Fosamprenavir Calcium 700 mg Tablet, Coated, 60-count
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🏷️ RxNorm drug class
This medicine belongs to the Protease inhibitors class.
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🏭 Manufacturer & labeler
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🩺 Clinical
Fosamprenavir is used to treat human immunodeficiency virus (HIV) infection. Fosamprenavir is in a class of medications called protease inhibitors. It works by decreasing the amount of HIV in the blood. Although fosamprenavir does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses. Taking these medications and making other life-style changes may decrease the risk of giving the HIV virus to other people.
Read the full MedlinePlus article ↗- Fosamprenavir is an HIV protease inhibitor — it blocks a key enzyme HIV needs to replicate. The reason you can't take it alone is that HIV is tricky: if it's only facing one type o...
- What exactly is fosamprenavir and why do I need to take other HIV medicines with it?
- It depends on the form you're taking. If you're taking the tablet, good news — you can take it with or without food, whichever is easier for you to stick to a routine. If you're ta...
- The most common side effects are diarrhea, nausea, vomiting, skin rash, and headache — these are usually manageable and don't necessarily mean you need to stop the medicine. The on...
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UNII M28OL1HH48
Croscarmellose sodium is a plant-based substance derived from cellulose. It acts as a disintegrant, helping tablets and capsules break down quickly in the digestive system so the medicine can be absorbed.
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UNII 7Z8S9VYZ4B
Ethylcellulose is a plant-derived thickener and film-former made by chemically modifying cellulose. It's used as a binder to hold tablet ingredients together, a coating to control how quickly medicine is released, or a thickener in liquid formulations.
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UNII 1K09F3G675
Ferric oxide red is an inorganic iron compound used as a colorant in medicines. It gives tablets, capsules, or other dosage forms a red or reddish tint for identification and appearance.
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UNII XM0M87F357
A dark iron oxide compound that gives medicines their black or dark color. It's used as a colorant in tablets and capsules to help identify the product and make it visually distinctive.
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UNII 3NXW29V3WO
Hypromellose is a plant-based thickener made from cellulose. It's used in medicines as a binder to hold ingredients together, a coating for tablets, and a thickener for liquids.
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UNII 70097M6I30
Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
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UNII OP1R32D61U
Microcrystalline cellulose is a purified form of cellulose, a natural fiber from plant sources. It acts as a binder and filler in tablets and capsules, helping hold ingredients together and give the medicine its shape and size.
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UNII FZ989GH94E
Povidone is a synthetic polymer made from a plastic-like material. It acts as a binder to hold tablet ingredients together and as a disintegrant to help the tablet break apart in your stomach so the medicine can be absorbed.
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UNII 6DC9Q167V3
Propylene glycol is a clear liquid derived from petroleum or vegetable sources. It acts as a solvent, humectant, and preservative in medicines, helping dissolve active ingredients and maintain product stability.
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UNII 46N107B71O
Shellac is a natural resin secreted by the lac beetle. It's used as a coating on tablets and capsules to control how quickly the medicine dissolves and to improve appearance and stability.
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UNII ETJ7Z6XBU4
Silicon dioxide is a naturally occurring mineral used as a glidant and anti-caking agent. It helps powder ingredients flow smoothly and prevents clumping during manufacturing and storage.
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UNII 7SEV7J4R1U
A powder made from a naturally occurring mineral. In medicines, talc works as a glidant and anti-caking agent, helping tablets and capsules flow smoothly during manufacturing and preventing clumping.
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UNII 15FIX9V2JP
Titanium dioxide is a bright white mineral powder commonly used as a colorant and opacifying agent. It makes pills and tablets white or lighter in color and helps make coatings non-transparent.
13 inactive ingredients listed in the exact product block matched to this NDC.
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| Price system | Per each | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | Not in the retail survey — common for institutional, discontinued, or low-volume packs. | |
| Medicaid paysCMS SDUD · 12 mo | No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data. | |
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🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Fosamprenavir Calcium 700 mg 00378-3520-91 | Mylan | 60 tablets | — | AB | FDA listed | — |
| Fosamprenavir Calcium 700 mgthis 63304-0583-60 | Sun | 60 tablets | — | AB | FDA listed | — |
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This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.
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📊 Medicare Part D spend CMS · PART D · 2026 (Q1)
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📦 Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Status |
|---|---|---|---|
| 63304-0583-01 | 100 TABLET, COATED in 1 BOTTLE (63304-583-01) | 2019-11-28 | Active |
| 63304-0583-30 | 30 TABLET, COATED in 1 BOTTLE (63304-583-30) | 2019-11-28 | Active |
| 63304-0583-60 You're viewing this | 60 TABLET, COATED in 1 BOTTLE (63304-583-60) | 2019-11-28 | Active |
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| NDC identity (package / product / labeler codes) | ✓ Available |
| Labeler | ✓ Available |
| Product & package description | ✓ Available |
| Marketing category & status | ✓ Available |
| Active ingredient / dosage form / route | ✓ Available |
| FDA label (SPL via DailyMed) | ✓ Available |
| Package photos | ✓ Available |
| Inactive ingredients (structured) | ✓ Available |
| NADAC pharmacy acquisition price (CMS) | — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey. |
| Orange Book / therapeutic-equivalence data | ✓ Available |
| HCPCS J-code billing crosswalk | — Not published for this NDC Most self-administered / retail products have no J-code — that is normal. |
| Medicaid utilization (CMS SDUD) | — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold. |
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📄 Full prescribing information FDA SPL
🎯 Indications and Usage ▾
1 INDICATIONS AND USAGE Fosamprenavir calcium tablets are indicated in combination with other antiretroviral agents for the treatment of human immunodeficiency virus (HIV-1) infection. The following points should be considered when initiating therapy with fosamprenavir calcium tablets plus ritonavir in protease inhibitor-experienced patients: The protease inhibitor-experienced patient trial was not large enough to reach a definitive conclusion that fosamprenavir calcium tablets plus ritonavir and lopinavir plus ritonavir are clinically equivalent [see Clinical Studies (14.2)] .
Once-daily administration of fosamprenavir calcium tablets plus ritonavir is not recommended for adult protease inhibitor-experienced patients or any pediatric patients [see Dosage and Administration (2.2, 2.3), Clinical Studies (14.2, 14.3)] . Dosing of fosamprenavir calcium tablets plus ritonavir is not recommended for protease inhibitor-experienced pediatric patients younger than 6 months [see Clinical Pharmacology (12.3)] . Fosamprenavir calcium tablets are HIV protease inhibitor indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection.
(1)
⏱️ Dosage and Administration ▾
2 DOSAGE AND ADMINISTRATION Therapy-Naive Adults: Fosamprenavir calcium tablets 1,400 mg twice daily; fosamprenavir calcium tablets 1,400 mg once daily plus ritonavir 200 mg once daily; fosamprenavir calcium tablets 1,400 mg once daily plus ritonavir 100 mg once daily; fosamprenavir calcium tablets 700 mg twice daily plus ritonavir 100 mg twice daily. (2.2) Protease Inhibitor-Experienced Adults: Fosamprenavir calcium tablets 700 mg twice daily plus ritonavir 100 mg twice daily. (2.2) Pregnant Patients: Fosamprenavir calcium tablets 700 mg twice daily plus ritonavir 100 mg twice daily should only be considered in women who are already on a stable twice-daily regimen of fosamprenavir calcium /ritonavir 700 mg/100 mg prior to pregnancy and who are virologically suppressed (HIV-1 RNA less than 50 copies per mL).
(2.2) Pediatric Patients (aged at least 4 weeks to 18 years): Dosage should be calculated based on body weight (kg) and should not exceed adult dose. (2.3) Hepatic Impairment: Recommended adjustments for patients with mild, moderate, or severe hepatic impairment. (2.4) Dosing Considerations Fosamprenavir calcium tablets may be taken with or without food.
(2.1) Fosamprenavir Calcium Oral Suspension: Adults should take without food; pediatric patients should take with food. (2.1)
2.1General Dosing Information Fosamprenavir calcium tablets may be taken with or without food. Adults should take fosamprenavir calcium oral suspension without food. Pediatric patients should take fosamprenavir calcium oral suspension with food [see Clinical Pharmacology (12.3)] .
If emesis occurs within 30 minutes after dosing, re-dosing of fosamprenavir calcium oral suspension should occur. Higher-than-approved dose combinations of fosamprenavir calcium tablets plus ritonavir are not recommended due to an increased risk of transaminase elevations [see Overdosage (10)] . When fosamprenavir calcium tablets are used in combination with ritonavir, prescribers should consult the full prescribing information for ritonavir.
2.2Adults Therapy-Naive Adults Fosamprenavir calcium tablets 1,400 mg twice daily (without ritonavir). Fosamprenavir calcium tablets 1,400 mg once daily plus ritonavir 200 mg once daily. Fosamprenavir calcium tablets 1,400 mg once daily plus ritonavir 100 mg once daily.
Fosamprenavir calcium tablets 700 mg twice daily plus ritonavir 100 mg twice daily. Dosing of fosamprenavir calcium tablets 1,400 mg once daily plus ritonavir 100 mg once daily is supported by pharmacokinetic data [see Clinical Pharmacology (12.3)] . Dosing of fosamprenavir calcium tablets 700 mg twice daily plus ritonavir 100 mg twice daily is supported by pharmacokinetic and safety data [see Clinical Pharmacology (12.3)] .
Protease Inhibitor-Experienced Adults Fosamprenavir calcium tablets 700 mg twice daily plus ritonavir 100 mg twice daily. Pregnancy Fosamprenavir calcium tablets 700 mg twice daily plus ritonavir 100 mg twice daily. Dosing of fosamprenavir calcium tablets 700 mg twice daily plus ritonavir 100 mg twice daily should only be considered in pregnant patients who are already on a stable twice-daily regimen of fosamprenavir calcium /ritonavir 700 mg/100 mg prior to pregnancy and who are virologically suppressed (HIV-1 RNA less than 50 copies per mL).
Lower exposures of amprenavir were observed during pregnancy; therefore, viral load should be monitored closely to ensure viral suppression is maintained [see Use in Specific Populations (8.1), Clinical Pharmacology (12.3)]. Data regarding use of other regimens of fosamprenavir calcium tablets (with or without ritonavir) in pregnancy are not available.
2.3Pediatric Patients (Aged at Least 4 Weeks to 18 Years) The recommended dosage of fosamprenavir calcium in patients aged at least 4 weeks to 18 years should be calculated based on body weight (kg) and should not exceed the recommended adult dose (Table 1). Table 1. Twice-Daily Dosage Regimens by Weight for Protease Inhibitor-Naive Pediatric Patients (Aged…
💊 Dosage Forms and Strengths ▾
3 DOSAGE FORMS AND STRENGTHS Fosamprenavir calcium tablets, USP, 700 mg, are pink colored, coated, oval-shaped tablets with “ RJ47 ” imprinted on one side with black ink and plain on the other side. 700 mg tablets (3)
⛔ Contraindications ▾
4 CONTRAINDICATIONS Fosamprenavir calcium is contraindicated in patients with previously demonstrated clinically significant hypersensitivity (e.g., Stevens-Johnson syndrome) to any of the components of this product or to amprenavir. Fosamprenavir calcium is contraindicated when coadministered with drugs that are highly dependent on cytochrome P450 (CYP)3A4 for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events. These drugs and other contraindicated drugs (which may lead to reduced efficacy of fosamprenavir calcium and possible resistance) are listed below [see Drug Interactions (7), Clinical Pharmacology (12.3)] .
The list of contraindicated drugs applies to the use of fosamprenavir calcium with or without ritonavir, unless otherwise indicated. If fosamprenavir calcium is coadministered with ritonavir, reference should be made to the full prescribing information for ritonavir for additional contraindications. Fosamprenavir calcium is contraindicated when coadministered with the following drugs: Alpha 1-adrenoreceptor antagonist: Alfuzosin Antiarrhythmics: Flecainide (with ritonavir ), propafenone (with ritonavir ) Antimycobacterial: Rifampin Antipsychotic: Lurasidone (with ritonavir ), pimozide Ergot derivatives: Dihydroergotamine, ergonovine, ergotamine, methylergonovine GI motility agent: Cisapride Herbal product: St.
John’s wort ( Hypericum perforatum ) Lipid modifying agents: Lomitapide, lovastatin, simvastatin Non-nucleoside reverse transcriptase inhibitor: Delavirdine PDE5 inhibitor: Sildenafil (Revatio) (for treatment of pulmonary arterial hypertension) Sedative/hypnotics: Midazolam, triazolam Hypersensitivity to fosamprenavir calcium or amprenavir (e.g., Stevens-Johnson syndrome). (4) Drugs highly dependent on cytochrome P450 (CYP)3A4 for clearance and for which elevated plasma levels may result in serious and/or life-threatening events.
(4) Review ritonavir contraindications when used in combination. (4)
⚠️ Warnings and Cautions ▾
5 WARNINGS AND PRECAUTIONS The concomitant use of fosamprenavir calcium with ritonavir and certain other drugs may result in known or potentially significant drug interactions. Consult the full prescribing information prior to and during treatment for potential drug interactions. (5.1, 7.3) Fosamprenavir calcium should be discontinued for severe skin reactions, including Stevens-Johnson syndrome.
(5.2) Fosamprenavir calcium should be used with caution in patients with a known sulfonamide allergy. (5.3) Use of higher-than-approved doses may lead to transaminase elevations. Patients with hepatitis B or C are at increased risk of transaminase elevations.
(5.4) Patients receiving fosamprenavir calcium may develop new onset or exacerbations of diabetes mellitus, hyperglycemia (5.5), immune reconstitution syndrome (5.6), increase of body fat (5.7), and elevated triglyceride and cholesterol concentrations (5.8). Monitor cholesterol and triglycerides prior to therapy and periodically thereafter. Acute hemolytic anemia has been reported with amprenavir.
(5.9) Hemophilia: Spontaneous bleeding may occur, and additional factor VIII may be required. (5.10) Nephrolithiasis: Cases of nephrolithiasis have been reported with fosamprenavir. (5.11)
5.1Risk of Serious Adverse Reactions Due to Drug Interactions Initiation of fosamprenavir calcium/ritonavir, a CYP3A inhibitor, in patients receiving medications metabolized by CYP3A, or initiation of medications metabolized by CYP3A in patients already receiving fosamprenavir calcium/ritonavir may increase plasma concentrations of medications metabolized by CYP3A. Initiation of medications that inhibit or induce CYP3A may increase or decrease concentrations of fosamprenavir calcium/ritonavir, respectively. These interactions may lead to: clinically significant adverse reactions, potentially leading to severe, life-threatening, or fatal events from greater exposures of concomitant medications. clinically significant adverse reactions from greater exposures of fosamprenavir calcium/ritonavir. loss of therapeutic effect of fosamprenavir calcium/ritonavir and possible development of resistance.
See Table 6 for steps to prevent or manage these possible and known significant drug interactions, including dosing recommendations [see Drug Interactions (7)] . Consider the potential for drug interactions prior to and during therapy with fosamprenavir calcium/ritonavir; review concomitant medications during therapy with fosamprenavir calcium/ritonavir, and monitor for the adverse reactions associated with the concomitant medications [see Contraindications (4), Drug Interactions (7)] .
5.2Skin Reactions Severe and life-threatening skin reactions, including 1 case of Stevens-Johnson syndrome among 700 subjects treated with fosamprenavir calcium in clinical trials. Treatment with fosamprenavir calcium should be discontinued for severe or life-threatening rashes and for moderate rashes accompanied by systemic symptoms [see Adverse Reactions (6)] .
5.3Sulfa Allergy Fosamprenavir calcium should be used with caution in patients with a known sulfonamide allergy. Fosamprenavir contains a sulfonamide moiety. The potential for cross-sensitivity between drugs in the sulfonamide class and fosamprenavir is unknown.
In a clinical trial of fosamprenavir calcium used as the sole protease inhibitor, rash occurred in 2 of 10 subjects (20%) with a history of sulfonamide allergy compared with 42 of 126 subjects (33%) with no history of sulfonamide allergy. In 2 clinical trials of fosamprenavir calcium plus low-dose ritonavir, rash occurred in 8 of 50 subjects (16%) with a history of sulfonamide allergy compared with 50 of 412 subjects (12%) with no history of sulfonamide allergy.
5.4Hepatic Toxicity Use of fosamprenavir calcium with ritonavir at higher-than-recommended dosages may result in transaminase elevations and should not be used [see Dosage and Administration (2), Overdosage (10)] . Patients with underlying hepatitis B o…
🤒 Adverse Reactions ▾
6 ADVERSE REACTIONS Severe or life-threatening skin reactions have been reported with the use of fosamprenavir calcium [see Warnings and Precautions (5.2)]. The most common moderate to severe adverse reactions in clinical trials of fosamprenavir calcium were diarrhea, rash, nausea, vomiting, and headache. Treatment discontinuation due to adverse events occurred in 6.4% of subjects receiving fosamprenavir calcium and in 5.9% of subjects receiving comparator treatments.
The most common adverse reactions leading to discontinuation of fosamprenavir calcium (incidence less than or equal to 1% of subjects) included diarrhea, nausea, vomiting, AST increased, ALT increased, and rash. In adults the most common adverse reactions (incidence greater than or equal to 4%) are diarrhea, rash, nausea, vomiting, and headache. (6.1) Vomiting and neutropenia were more frequent in pediatrics than in adults.
(6.1) To report SUSPECTED ADVERSE REACTIONS, contact Sun Pharmaceutical Industries, Inc. at 1-800-406-7984 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
6.1Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Adult Trials The data for the 3 active-controlled clinical trials described below reflect exposure of 700 HIV-1-infected subjects to fosamprenavir calcium tablets, including 599 subjects exposed to fosamprenavir calcium for greater than 24 weeks, and 409 subjects exposed for greater than 48 weeks.
The population age ranged from 17 to 72 years. Of these subjects, 26% were female, 51% white, 31% black, 16% American Hispanic, and 70% were antiretroviral-naive. Sixty-one percent received fosamprenavir calcium 1,400 mg once daily plus ritonavir 200 mg once daily; 24% received fosamprenavir calcium 1,400 mg twice daily; and 15% received fosamprenavir calcium 700 mg twice daily plus ritonavir 100 mg twice daily.
Selected adverse reactions reported during the clinical efficacy trials of fosamprenavir calcium are shown in Tables 2 and 3. Each table presents adverse reactions of moderate or severe intensity in subjects treated with combination therapy for up to 48 weeks. Table 2.
Selected Moderate/Severe Clinical Adverse Reactions Reported in Greater than or Equal to 2% of Antiretroviral-Naive Adult Subjects Adverse Reaction APV30001 a APV30002 a Fosamprenavir Calcium 1,400 mg Twice Daily (n = 166) Nelfinavir 1,250 mg Twice Daily (n = 83) Fosamprenavir Calcium 1,400 mg and Ritonavir 200 mg Once Daily (n = 322) Nelfinavir 1,250 mg Twice Daily (n = 327) Gastrointestinal Diarrhea 5% 18% 10% 18% Nausea 7% 4% 7% 5% Vomiting 2% 4% 6% 4% Abdominal pain 1% 0% 2% 2% Skin Rash 8% 2% 3% 2% General disorders Fatigue 2% 1% 4% 2% Nervous system Headache 2% 4% 3% 3% a All subjects also received abacavir and lamivudine twice daily.
Table 3. Selected Moderate/Severe Clinical Adverse Reactions Reported in Greater than or Equal to 2% of Protease Inhibitor-Experienced Adult Subjects (Trial APV30003) Adverse Reaction Fosamprenavir Calcium 700 mg and Ritonavir 100 mg Twice Daily a (n = 106) Lopinavir 400 mg and Ritonavir 100 mg Twice Daily a (n = 103) Gastrointestinal Diarrhea 13% 11% Nausea 3% 9% Vomiting 3% 5% Abdominal pain < 1% 2% Skin Rash 3% 0% Nervous system Headache 4% 2% a All subjects also received 2 reverse transcriptase inhibitors. Skin rash (without regard to causality) occurred in approximately 19% of subjects treated with fosamprenavir calcium in the pivotal efficacy trials.
Rashes were usually maculopapular and of mild or moderate intensity, some with pruritus. Rash had a median onset of 11 days after initiation of fosamprenavir calcium and had a median duration of 13 days. Skin rash led to discontinuation of fosamprenavir calcium in less than 1% of subjects.
In some subjects with mild or moderate rash, d…
🔄 Drug Interactions ▾
7 DRUG INTERACTIONS Coadministration of fosamprenavir calcium with drugs that induce CYP3A4 may decrease amprenavir (active metabolite) concentrations leading to potential loss of virologic activity. (7, 12.3) Coadministration with drugs that inhibit CYP3A4 may increase amprenavir concentrations. (7, 12.3) Coadministration of fosamprenavir calcium or fosamprenavir calcium and ritonavir may result in clinically significant interactions with drugs metabolized by CYP3A4.
(7) Coadministration of fosamprenavir calcium and ritonavir may result in clinically significant interactions with drugs metabolized by CYP2D6. (7)
7.1Cytochrome P450 Inhibitors and Inducers Amprenavir, the active metabolite of fosamprenavir, is an inhibitor of CYP3A4 metabolism and therefore should not be administered concurrently with medications with narrow therapeutic windows that are substrates of CYP3A4. Data also suggest that amprenavir induces CYP3A4. Amprenavir is metabolized by CYP3A4.
Coadministration of fosamprenavir calcium and drugs that induce CYP3A4, such as rifampin, may decrease amprenavir concentrations and reduce its therapeutic effect. Coadministration of fosamprenavir calcium and drugs that inhibit CYP3A4 may increase amprenavir concentrations and increase the incidence of adverse effects. The potential for drug interactions with fosamprenavir calcium changes when fosamprenavir calcium is coadministered with the potent CYP3A4 inhibitor ritonavir.
The magnitude of CYP3A4-mediated drug interactions (effect on amprenavir or effect on coadministered drug) may change when fosamprenavir calcium is coadministered with ritonavir. Because ritonavir is a CYP2D6 inhibitor, clinically significant interactions with drugs metabolized by CYP2D6 are possible when coadministered with fosamprenavir calcium plus ritonavir. Ritonavir also appears to induce CYP3A, CYP1A2, CYP2C9, CYP2C19, and CYP2B6, as well as other enzymes, including glucuronosyl transferase.
There are other agents that may result in serious and/or life-threatening drug interactions [see Contraindications (4)] .
7.2Established and Other Potentially Significant Drug Interactions If fosamprenavir calcium is used in combination with ritonavir, see full prescribing information for ritonavir for additional information on drug interactions [see Contraindications (4), Clinical Pharmacology (12.3)] . Table 6 provides a listing of established or potentially clinically significant drug interactions. Information in the table applies to fosamprenavir calcium with or without ritonavir, unless otherwise indicated.
Table 6. Established and Other Potentially Significant Drug Interactions Concomitant Drug Class: Drug Name Effect on Concentration of Amprenavir or Concomitant Drug Clinical Comment HCV/HIV-Antiviral Agents HCV protease inhibitor: Boceprevir Fosamprenavir calcium: ↓ Amprenavir (predicted) ↔ or ↓ Boceprevir (predicted) Fosamprenavir calcium /ritonavir: ↓Amprenavir (predicted) ↓Boceprevir (predicted) Coadministration of fosamprenavir calcium or fosamprenavir calcium/ ritonavir and boceprevir is not recommended. HCV protease inhibitor: Simeprevir Fosamprenavir calcium: ↔ Amprenavir (predicted) ↑ or ↓ Simeprevir (predicted) Fosamprenavir calcium /ritonavir: ↔Amprenavir (predicted) ↑Simeprevir (predicted) Coadministration of fosamprenavir calcium or fosamprenavir calcium/ritonavir and simeprevir is not recommended.
HCV protease inhibitor: Paritaprevir (coformulated with ritonavir and ombitasvir and coadministered with dasabuvir) Fosamprenavir calcium: ↑Amprenavir (predicted) ↑ or ↔Paritaprevir (predicted) Fosamprenavir calcium /ritonavir: ↑ or ↔Amprenavir (predicted) ↑Paritaprevir (predicted) Appropriate doses of the combinations with respect to safety and efficacy have not been established. Fosamprenavircalcium 1,400 mg once daily may be considered when coadministered with paritaprevir/ritonavir/ombitasvir/ dasabuvir. Coadministration of Fosamprenavircalcium /ritonavir and paritaprevir/ritonavir/omb…
👥 Use in Specific Populations ▾
8 USE IN SPECIFIC POPULATIONS Lactation: Breastfeeding is not recommended due to potential for HIV transmission. (8.2)
8.1Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to fosamprenavir calcium during pregnancy. Healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263. Risk Summary Limited data are available for use of fosamprenavir calcium in pregnancy. fosamprenavir calcium 700 mg twice daily taken with ritonavir 100 mg twice daily should only be considered in pregnant patients who are already on a stable twice-daily regimen of fosamprenavir calcium/ritonavir 700 mg/100 mg prior to pregnancy, and who are virologically suppressed (HIV-1 RNA less than 50 copies per mL) (see Clinical Considerations and Data).
There are insufficient human data on the use of fosamprenavir during pregnancy to adequately assess a drug-associated risk for birth defects and miscarriage. Given the limited number of pregnancies exposed to fosamprenavir-based regimens, no conclusions can be drawn on the safety of fosamprenavir in pregnancy. The background risk for major birth defects and miscarriage for the indicated population is unknown.
The background rate for major birth defects in a U.S. reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP) is 2.7% (see Data) . The estimated background rate of miscarriage in clinically recognized pregnancies in the U.S. general population is 15% to 20%. In animal reproduction studies, no evidence of major adverse developmental outcomes was observed following oral administration of fosamprenavir.
Systemic exposure to amprenavir (the active ingredient) was less than (rabbits) or up to 2 times (rats) those in humans at the maximum recommended human dose (MRHD) with or without ritonavir. In contrast, oral administration of amprenavir was associated with abortions in pregnant rabbits at doses that produced approximately one-twentieth the human exposure at the MRHD. In the rat pre- and postnatal development study, toxicities to the offspring, including reduced survival and reproductive performance, were observed at maternal systemic exposures (AUC) to amprenavir that were approximately 2 times the exposure in humans at the MRHD of fosamprenavir alone or approximately the same as those seen in humans following administration of the MRHD of fosamprenavir in combination with ritonavir (see Data).
Clinical Considerations Virologic Monitoring During Pregnancy and the Postpartum Period: Based on limited data on the use of fosamprenavir calcium during pregnancy, no dosage adjustments are required for pregnant patients who are already on a stable twice-daily regimen of fosamprenavir calcium 700 mg taken with ritonavir 100 mg prior to pregnancy, and who are virologically suppressed (HIV-1 RNA less than 50 copies per mL) [see Dosage and Administration (2.3), Clinical Pharmacology (12.3)] . In a clinical trial of 10 HIV-1–infected pregnant women treated with fosamprenavir calcium 700 mg taken with ritonavir 100 mg twice daily through postpartum, total amprenavir exposures were lower during pregnancy compared with the postpartum period.
Therefore, viral load should be monitored closely to ensure viral suppression is maintained [see Data, Dosage and Administration (2.2), Clinical Pharmacology (12.3)] . Pregnancy data with other dosage regimens of fosamprenavir calcium (with or without ritonavir) are not available. Data Human Data: fosamprenavir calcium 700 mg taken with ritonavir 100 mg twice daily in combination with a background regimen was evaluated in a clinical trial of 10 HIV-1–infected pregnant women during the second and third trimesters and postpartum.
Subjects initiated fosamprenavir calcium /ritonavir during pregnancy at a median of 19 weeks’ gestation; 4 had undetectable HIV-1 RNA viral load (less than 50 copies/mL) at the time of initiation…
🤰 Pregnancy ▾
8.1Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to fosamprenavir calcium during pregnancy. Healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263. Risk Summary Limited data are available for use of fosamprenavir calcium in pregnancy. fosamprenavir calcium 700 mg twice daily taken with ritonavir 100 mg twice daily should only be considered in pregnant patients who are already on a stable twice-daily regimen of fosamprenavir calcium/ritonavir 700 mg/100 mg prior to pregnancy, and who are virologically suppressed (HIV-1 RNA less than 50 copies per mL) (see Clinical Considerations and Data).
There are insufficient human data on the use of fosamprenavir during pregnancy to adequately assess a drug-associated risk for birth defects and miscarriage. Given the limited number of pregnancies exposed to fosamprenavir-based regimens, no conclusions can be drawn on the safety of fosamprenavir in pregnancy. The background risk for major birth defects and miscarriage for the indicated population is unknown.
The background rate for major birth defects in a U.S. reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP) is 2.7% (see Data) . The estimated background rate of miscarriage in clinically recognized pregnancies in the U.S. general population is 15% to 20%. In animal reproduction studies, no evidence of major adverse developmental outcomes was observed following oral administration of fosamprenavir.
Systemic exposure to amprenavir (the active ingredient) was less than (rabbits) or up to 2 times (rats) those in humans at the maximum recommended human dose (MRHD) with or without ritonavir. In contrast, oral administration of amprenavir was associated with abortions in pregnant rabbits at doses that produced approximately one-twentieth the human exposure at the MRHD. In the rat pre- and postnatal development study, toxicities to the offspring, including reduced survival and reproductive performance, were observed at maternal systemic exposures (AUC) to amprenavir that were approximately 2 times the exposure in humans at the MRHD of fosamprenavir alone or approximately the same as those seen in humans following administration of the MRHD of fosamprenavir in combination with ritonavir (see Data).
Clinical Considerations Virologic Monitoring During Pregnancy and the Postpartum Period: Based on limited data on the use of fosamprenavir calcium during pregnancy, no dosage adjustments are required for pregnant patients who are already on a stable twice-daily regimen of fosamprenavir calcium 700 mg taken with ritonavir 100 mg prior to pregnancy, and who are virologically suppressed (HIV-1 RNA less than 50 copies per mL) [see Dosage and Administration (2.3), Clinical Pharmacology (12.3)] . In a clinical trial of 10 HIV-1–infected pregnant women treated with fosamprenavir calcium 700 mg taken with ritonavir 100 mg twice daily through postpartum, total amprenavir exposures were lower during pregnancy compared with the postpartum period.
Therefore, viral load should be monitored closely to ensure viral suppression is maintained [see Data, Dosage and Administration (2.2), Clinical Pharmacology (12.3)] . Pregnancy data with other dosage regimens of fosamprenavir calcium (with or without ritonavir) are not available. Data Human Data: fosamprenavir calcium 700 mg taken with ritonavir 100 mg twice daily in combination with a background regimen was evaluated in a clinical trial of 10 HIV-1–infected pregnant women during the second and third trimesters and postpartum.
Subjects initiated fosamprenavir calcium /ritonavir during pregnancy at a median of 19 weeks’ gestation; 4 had undetectable HIV-1 RNA viral load (less than 50 copies/mL) at the time of initiation. Amprenavir pharmacokinetics and placental transfer were studied during the second trimester (n = 6) or third trimeste…
🧒 Pediatric Use ▾
8.4Pediatric Use The safety, pharmacokinetic profile, and virologic and immunologic responses of fosamprenavir calcium with and without ritonavir were evaluated in protease inhibitor-naive and -experienced HIV-1–infected pediatric subjects aged at least 4 weeks to younger than 18 years and weighing at least 3 kg in 3 open-label trials [see Adverse Reactions (6.1), Clinical Pharmacology (12.3), Clinical Studies (14.3)] . Treatment with fosamprenavir calcium is not recommended in protease inhibitor-experienced pediatric patients younger than 6 months.
The pharmacokinetics, safety, tolerability, and efficacy of fosamprenavir calcium in pediatric patients younger than 4 weeks have not been established [see Clinical Pharmacology (12.3)] . Available pharmacokinetic and clinical data do not support once-daily dosing of fosamprenavir calcium alone or in combination with ritonavir for any pediatrics or twice-daily dosing without ritonavir in pediatric patients younger than 2 years [see Clinical Pharmacology (12.3), Clinical Studies (14.3)] . See Dosage and Administration (2.3) for dosing recommendations for pediatric patients.
🧓 Geriatric Use ▾
8.5Geriatric Use Clinical studies of fosamprenavir calcium did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently from younger adults. In general, dose selection for an elderly patient should be cautious, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy.
🆘 Overdosage ▾
10 OVERDOSAGE In a healthy volunteer repeat-dose pharmacokinetic trial evaluating high-dose combinations of fosamprenavir calcium plus ritonavir, an increased frequency of Grade 2/3 ALT elevations (greater than 2.5 x ULN) was observed with fosamprenavir calcium 1,400 mg twice daily plus ritonavir 200 mg twice daily (4 of 25 subjects). Concurrent Grade 1/2 elevations in AST (greater than 1.25 x ULN) were noted in 3 of these 4 subjects. These transaminase elevations resolved following discontinuation of dosing.
There is no known antidote for fosamprenavir calcium. It is not known whether amprenavir can be removed by peritoneal dialysis or hemodialysis, although it is unlikely as amprenavir is highly protein bound. If overdosage occurs, the patient should be monitored for evidence of toxicity and standard supportive treatment applied as necessary.
🧬 Clinical Pharmacology ▾
12 CLINICAL PHARMACOLOGY
12.1Mechanism of Action Fosamprenavir is an HIV-1 antiretroviral agent [see Microbiology (12.4)] .
12.3Pharmacokinetics The pharmacokinetic properties of amprenavir after administration of fosamprenavir calcium, with or without ritonavir, have been evaluated in both healthy adult volunteers and in HIV-1-infected subjects; no substantial differences in steady-state amprenavir concentrations were observed between the 2 populations. The pharmacokinetic parameters of amprenavir after administration of fosamprenavir calcium (with and without concomitant ritonavir) are shown in Table 7. Table 7.
Geometric Mean (95% CI) Steady-State Plasma Amprenavir Pharmacokinetic Parameters in Adults Regimen C max (mcg/mL) T max (hours) a AUC 24 (mcg•h/mL) C tau b (mcg/mL) Fosamprenavir calcium 1,400 mg Twice Daily(n = 22) c 4.82 (4.06 to 5.72) 1.3 (0.8to 4) 33 d (27.6to 39.2) 0.35 (0.27to 0.46) Fosamprenavir calcium 1,400 mg Once Daily plus Ritonavir 200 mg Once Daily (n = 22) e 7.24 (6.32 to 8.28) 2.1 (0.8t o 5) 69.4 (59.7 to 80.8) 1.45 (1.16 to 1.81) Fosamprenavir calcium 1,400 mg Once Daily plus Ritonavir 100 mg Once Daily (n = 36) e 7.93 (7.25 to 8.68) 1.5 (0.75 to 5) 66.4 (61.1 to 72.1) 0.86 (0.74 to 1.01) Fosamprenavir calcium 700 mg Twice Daily plus Ritonavir 100 mg Twice Daily (n = 24) e 6.08 (5.38 to 6.86) 1.5 (0.75 to 5) 79.2 d (69 to 90.6) 2.12 (1.77 to 2.54) a Data shown are median (range). b C tau is the concentration at the end of the dose interval. c HIV-infected adults. d AUC 24 was calculated from AUC 12 summary data x 2. e Healthy adults.
The mean plasma amprenavir concentrations of the dosing regimens over the dosing intervals are displayed in Figure 1. Figure 1. Mean (±SD) Steady-State Plasma Amprenavir Concentrations and Mean EC 50 Values against HIV from Protease Inhibitor-Naive Subjects (in the Absence of Human Serum) Absorption After administration of a single dose of fosamprenavir calcium to HIV-1-infected subjects, the time to peak amprenavir concentration (T max ) occurred between 1.5 and 4 hours (median 2.5 hours).
The absolute oral bioavailability of amprenavir after administration of fosamprenavir calcium in humans has not been established. After administration of a single 1,400-mg dose in the fasted state, fosamprenavir calcium oral suspension (50 mg per mL) and fosamprenavir calcium tablets (700 mg) provided similar amprenavir exposures (AUC); however, the C max of amprenavir after administration of the suspension formulation was 14.5% higher compared with the tablet. Amprenavir is both a substrate for and inducer of P-glycoprotein.
Effects of Food on Oral Absorption Administration of a single 1,400 mg dose of fosamprenavir calcium tablets in the fed state (standardized high-fat meal: 967 kcal, 67 grams fat, 33 grams protein, 58 grams carbohydrate) compared with the fasted state was associated with no significant changes in amprenavir C max , T max , or AUC 0-∞ [see Dosage and Administration (2)] . Administration of a single 1,400 mg dose of fosamprenavir calcium oral suspension in the fed state (standardized high-fat meal: 967 kcal, 67 grams fat, 33 grams protein, 58 grams carbohydrate) compared with the fasted state was associated with a 46% reduction in C max , a 0.72-hour delay in T max , and a 28% reduction in amprenavir AUC 0-∞.
Distribution In vitro , amprenavir is approximately 90% bound to plasma proteins, primarily to alpha 1 -acid glycoprotein. In vitro , concentration-dependent binding was observed over the concentration range of 1 to 10 mcg per mL, with decreased binding at higher concentrations. The partitioning of amprenavir into erythrocytes is low, but increases as amprenavir concentrations increase, reflecting the higher amount of unbound drug at higher concentrations.
Metabolism After oral administration, fosamprenavir is rapidly and almost completely hydrolyzed to amprenavir and inorganic phosphate prior to reaching the systemic circulation. This occurs in the gut epit…
🧬 Mechanism of Action ▾
12.1Mechanism of Action Fosamprenavir is an HIV-1 antiretroviral agent [see Microbiology (12.4)] .
📦 How Supplied / Storage and Handling ▾
16 HOW SUPPLIED/STORAGE AND HANDLING Fosamprenavir calcium tablets, USP, 700 mg, are pink colored, coated, oval-shaped tablets with “RJ47” imprinted on one side with black ink and plain on the other side. They are supplied as follows- NDC 63304-583-30 Bottles of 30 with child-resistant closure NDC 63304-583-60 Bottles of 60 with child-resistant closure NDC 63304-583-01 Bottles of 100 Store at 20° C to 25° C (68° F to 77° F) [See USP Controlled Room Temperature]. Keep bottle tightly closed.
Protect from moisture.
📋 Description ▾
11 DESCRIPTION Fosamprenavir calcium, USP is a prodrug of amprenavir, an inhibitor of HIV protease. The chemical name of fosamprenavir calcium, USP is (3S)-tetrahydrofuran-3-yl (1S,2R)-3-[[(4-aminophenyl) sulfonyl](isobutyl)amino]-1-benzyl-2-(phosphonooxy) propylcarbamate monocalcium salt. Fosamprenavir calcium, USP is a single stereoisomer with the (3S)(1S,2R) configuration.
It has a molecular formula of C25H34CaN3O9PS and a molecular weight of 623.7. It has the following structural formula: Fosamprenavir calcium, USP is a white to cream color solid which is soluble in methanol. Fosamprenavir calcium tablets, USP are available for oral administration in a strength of 700 mg of fosamprenavir as fosamprenavir calcium, USP (equivalent to approximately 600 mg of amprenavir).
Each 700 mg tablet contains the inactive ingredients colloidal silicon dioxide, croscarmellose sodium, magnesium stearate, microcrystalline cellulose, and povidone. The tablet coating contains the inactive ingredients ethylcellulose, ferric oxide red, hypromellose, talc, and titanium dioxide. The imprinting ink contains the inactive ingredients ferric oxide black, propylene glycol, and shellac.
Meets USP dissolution test 3. Structure
💬 Information for Patients ▾
17 PATIENT COUNSELING INFORMATION Advise the patient to read the FDA-approved patient labeling (Patient Information). Drug Interactions A statement to patients and healthcare providers is included on the product’s bottle label: ALERT: Find out about medicines that should NOT be taken with fosamprenavir calcium tablets. Fosamprenavir calcium tablets may interact with many drugs; therefore, advise patients to report to their healthcare provider the use of any other prescription or nonprescription medication or herbal products, particularly St.
John’s wort. Advise patients receiving PDE5 inhibitors that they may be at an increased risk of PDE5 inhibitor-associated adverse events, including hypotension, visual changes, and priapism, and should promptly report any symptoms to their healthcare provider [see Contraindications (4), Warnings and Precautions (5.1), Drug Interactions (7)]. Contraception Instruct patients receiving combined hormonal contraception to use an effective alternative contraceptive method or an additional barrier method during therapy with fosamprenavir calcium tablets because hormonal levels may decrease, and if used in combination with fosamprenavir calcium tablets and ritonavir, liver enzyme elevations may occur [see Drug Interactions (7.2), Use in Specific Populations (8.3)] .
Severe Skin Reactions Advise patients that skin reactions ranging from mild to severe, including Stevens-Johnson Syndrome, have been reported with fosamprenavir calcium tablets. Advise patients to discontinue fosamprenavir calcium tablets immediately for severe or life-threatening skin reactions or for moderate rashes accompanied by systemic symptoms [see Warnings and Precautions (5.2), Adverse Reactions (6)] . Sulfa Allergy Advise patients to inform their healthcare provider if they have a sulfa allergy.
The potential for cross-sensitivity between drugs in the sulfonamide class and fosamprenavir is unknown [see Warnings and Precautions (5.3)]. Hepatic Toxicity Advise patients that it is recommended to have laboratory testing before and during therapy as patients with underlying hepatitis B or C or marked elevations of transaminases prior to treatment may be at increased risk for developing or worsening transaminase elevations with use of fosamprenavir calcium tablets, particularly at higher than recommended doses which should not be used. [see Warnings and Precautions (5.4)] .
Immune Reconstitution Syndrome Advise patients to inform their healthcare provider immediately of any signs or symptoms of infection as inflammation from previous infection may occur soon after combination antiretroviral therapy, including when fosamprenavir calcium tablets is started [see Warnings and Precautions (5.6)] . Increase in Body Fat Inform patients that an increase of body fat may occur in patients receiving protease inhibitors, including fosamprenavir calcium tablets, and that the cause and long-term health effects of these conditions are not known at this time [see Warnings and Precautions (5.7)] .
Lipid Elevations Advise patients that it is recommended to have laboratory testing before and during therapy as increases in the concentration of triglycerides and cholesterol have been reported with use of fosamprenavir calcium tablets [see Warnings and Precautions (5.8), Adverse Reactions (6)] . Pregnancy Registry Advise patients that there is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to fosamprenavir calcium tablets during pregnancy [see Use in Specific Populations (8.1)] . Lactation Instruct women with HIV-1 infection not to breastfeed because HIV-1 can be passed to the baby in the breast milk [see Use in Specific Populations (8.2)] .
Missed Dose Instruct patients that if they miss a dose of fosamprenavir calcium tablets, to take it as soon as they remember. Advise patients not to double their next dose or take more than the prescribed dose [see Dosage and Administration (2)] . All trademarks are the property of t…