HomeNDC LookupIngredientsPrimaquine Phosphate › 50742-0191-01
PRIMAQUINE PHOSPHATE 15 mg Tablet, Film Coated, 100-count — NDC 50742-0191-01 package photo

PRIMAQUINE PHOSPHATE 15 mg Tablet, Film Coated, 100-count

by Ingenus Pharmaceuticals, LLC · 100 TABLET, FILM COATED in 1 BOTTLE, PLASTIC (50742-191-01)
NDC 50742-0191-01
🏷️ FDA NDC (as labeled) 50742-191-01 billing pads the product segment with a zero
This package
Contains100-count Pack sizes2 compare ↓
Also priced by: Part D plans $1.96/unit — full pricing hub ↓
Also comes in: 500 tablets 50742-0191-05
Rx only Generic On market Non-controlled
🗂️ Data synced Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

🆔 Identity & classification

FDA NDC (as labeled) 50742-191-01
Product NDC 50742-191
11-digit billing NDC 50742019101
RxCUI 904170
UNII H0982HF78B
UPC 0350742191055
Application # ANDA206043
SPL Set ID 09531382-2e06-4164-a7e1-169a1488788a
Established class (EPC) Antimalarial
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2018-01-23
Route ORAL
Dosage form TABLET, FILM COATED
Substance PRIMAQUINE PHOSPHATE
GPI-14 13000030100310
GPI class Primaquine Phosphate
GCN Seq No 009577
GCN 42910
HICL code 004148
Ingredient (HICL) Primaquine Phosphate
HIC1 code W
Therapeutic class — broad (HIC1) Anti-Infecting Agents
HIC2 code W4
Therapeutic class — intermediate (HIC2) Antiparasitics
HIC3 code W4A
Therapeutic class — specific (HIC3) Antimalarial Drugs
AHFS code 08:30.08.00
AHFS class Antimalarials
FDB label name PRIMAQUINE 26.3 MG TABLET
FDB brand name Primaquine
Legend status F — Federal legend — prescription drug or device
TE code (Orange Book) AB · RLD · RS
Why two NDCs? The FDA registers this code as 50742-191-01 — a 5-3-2 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the product segment → 50742-0191-01. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

🏷️ RxNorm drug class

This medicine belongs to the Antimalarial class.

Pharmacologic class Antimalarial
Drug family (ATC) Aminoquinolines
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

🏭 Manufacturer & labeler

LabelerIngenus Pharmaceuticals, LLC
Application holderINGENUS PHARMACEUTICALS LLC
FDA applicationANDA206043 (ANDA)
Labeler code50742
First marketedJan 2018
Product typeHuman Prescription Drug
Portfolio139 products on file
The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

🩺 Clinical

Label name PRIMAQUINE 26.3 MG TABLET Ingredient Primaquine Phosphate
📖 What it is MedlinePlus · NLM

Primaquine is used to treat malaria (a serious infection spread by mosquitoes in some parts of the world) and to prevent the disease from coming back. Primaquine is in a class of medications called antimalarials. It works by killing the organisms that cause malaria.

Read the full MedlinePlus article ↗
📗 Our plain-language guide HelloPharmacist
  • Great question — this trips a lot of people up. Chloroquine clears the malaria parasites from your blood quickly and stops the active illness. But with vivax malaria, some parasite...
  • Why do I need to take primaquine if I already took chloroquine for malaria?
  • G6PD is an enzyme that helps protect your red blood cells from damage. Some people — particularly those with ancestry from Africa, the Mediterranean, the Middle East, South-East As...
  • What is G6PD deficiency, and why does my doctor need to test me before I start?
📖 Read our full Primaquine guide →
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

💊 What it looks like

Color orange
ShapeRound
Imprint059
Size7 mm
ScoringNot scored
One label can cover several strengths, so colors may be combined — always confirm a loose pill against the dispensed prescription label or a pharmacist.
Where does this data come from?
Physical description (imprint, shape, color, scoring, coating) from this product’s FDA Structured Product Labeling (SPL), mirrored from DailyMed / openFDA.

🧪 Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.

  • 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.
  • UNII H77VEI93A8
    A synthetic yellow dye used to color medications. It helps identify the drug and make it visually distinctive, with no effect on how the medicine works.
  • UNII 36SFW2JZ0W
    Hypromellose 2910 is a plant-based thickening agent derived from cellulose. In medicines, it forms a protective coating on tablets or capsules and controls how quickly the drug dissolves and releases into your body.
  • UNII EWQ57Q8I5X
    Lactose monohydrate is a natural sugar derived from milk. It serves as a filler and binder in tablets and capsules, helping create the proper size, texture, and consistency of the medicine.
  • 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.
  • UNII O8232NY3SJ
    A plant-based carbohydrate derived from corn kernels. It acts as a filler to add bulk, a binder to hold ingredients together, and a disintegrant to help the tablet break apart in your stomach for absorption.
  • 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.
  • 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.
  • UNII XHX3C3X673
    Triacetin is a clear, oily liquid made from glycerin and acetic acid. It works as a plasticizer and solvent in medicines, helping soften coatings and improve how liquids mix together in formulations.

9 inactive ingredients listed in the exact product block matched to this NDC.

Where does this data come from?
Data sourced from official FDA Structured Product Labeling (SPL) via DailyMedingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

💲 Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer eachPer 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.
Medicare drug plans payPart D · Q2 2026 $1.96 $195.92 / 100 tablets
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

🔁 Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Primaquine Phosphate 15 mg 00024-1596-01 Sanofi-Aventis 100 tablets $1.964 AB Availability likely
Primaquine Phosphate 15 mg 76385-0102-01 Unichem 100 tablets $1.964 AB Availability likely
Primaquine Phosphate 15 mg 42291-0510-01 AvKARE 100 tablets AB FDA listed
Primaquine Phosphate 15 mg 43063-0721-14 PD-Rx 14 tablets AB FDA listed
Primaquine Phosphate 15 mgthis 50742-0191-01 Ingenus 100 tablets AB FDA listed
About this product: this is a generic version of the medicine. FDA equivalence ratings are shown when available, and other versions are listed above, least expensive first.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

Availability & generic status

🏛️
2018
On the market since
Jan 2018
📍
2026
Currently FDA-listed
8 years listed
🔓
·
Generic on the market
this product is a generic
This is a generic drug

This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.

Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

📊 Medicare Part D spend CMS · PART D · 2026 (Q1)

Medicare Part D (outpatient prescription) spending for Primaquine (matched by generic name) — the program that covers self-administered drugs. 2 manufacturers.
⚠️ Drug-level data: CMS publishes Part D spending by drug, not by NDC — these figures combine every manufacturer, strength and package size sold under the name Primaquine. That’s a different level of aggregation than the Medicaid card above, which is specific to this exact 11-digit NDC (pack size included), so the two aren’t directly comparable.
Period
Total Part D spend
$6.2K
Claims incl. refills
122
Beneficiaries
101
Spend / beneficiary
$61.80
Spend / claim
$51.16
Trend by period
💵 About the dollar figures: spending is what Part D plans paid before confidential manufacturer rebates, so the program’s real net cost is lower. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part D Spending by Drug (data.cms.gov), updated quarterly.

📦 Packaging — all sizes for this product

Package NDCDescription Per unit Per pack Marketing startStatus
50742-0191-01 You're viewing this 100 TABLET, FILM COATED in 1 BOTTLE, PLASTIC (50742-191-01) 2018-01-23 Active
50742-0191-05 500 TABLET, FILM COATED in 1 BOTTLE, PLASTIC (50742-191-05) $1.96 / ea $981.93 2018-01-23 Active

You're viewing the smallest of 2 pack sizes for this product.

Pack size FAQ

What quantity is in NDC 50742-0191-01?
NDC 50742-0191-01 is a 100-count package — 100 tablet, film coated in 1 bottle, plastic.
What is the difference between NDC 50742-0191-01 and NDC 50742-0191-05?
Both are PRIMAQUINE PHOSPHATE 15 mg Tablet, Film Coated — the drug itself is identical. NDC 50742-0191-01 is the 100-count package, while NDC 50742-0191-05 is the 500 tablets package.
What NDC number is used to bill for this package of PRIMAQUINE PHOSPHATE 15 mg Tablet, Film Coated?
Bill NDC 50742-0191-01 — the 11-digit billing format is 50742019101. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

Prices are the latest CMS NADAC pharmacy acquisition cost per NDC; per-pack figures are per-unit × pack quantity, shown only when the pack is denominated in the same measure NADAC prices.

🧭 About this NDC listing & data coverage

Finished prescription product
What data is (and isn’t) available for this NDC — tap to expand
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.
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Why is there no price listed?
The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The FDA registers it as 50742-191-01, which is what is printed on the packaging and shown on DailyMed. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero: 50742-0191-01, written without dashes as 50742019101. The Identity section at the top of this page lists every form of this code.
What do the three segments of this NDC mean?
In 50742-0191-01, the first segment (50742) is the labeler code FDA assigned to Ingenus Pharmaceuticals, LLC; the middle segment (0191) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (01) identifies this exact package size and type. Together they name one specific package of one specific product.
Is this package still being marketed?
Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by Ingenus Pharmaceuticals, LLC. Listing status can change — the directory data on this page refreshes weekly.
Does this product come in other package sizes?
Yes — the FDA directory lists 1 other package presentation of this same product, including 500 tablets (50742-0191-05). Each has its own NDC and its own page — see the package list near the top of this page.
Who lists this product with the FDA?
Ingenus Pharmaceuticals, LLC is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
Do I need a prescription for this product?
This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.

📄 Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Jump with a chip, search within the label, or expand everything.
🎯 Indications and Usage 17 words

INDICATIONS AND USAGE Primaquine phosphate is indicated for the radical cure (prevention of relapse) of vivax malaria.

⏱️ Dosage and Administration 124 words

DOSAGE AND ADMINISTRATION Primaquine phosphate tablets are recommended only for the radical cure of vivax malaria, the prevention of relapse in vivax malaria, or following the termination of chloroquine phosphate suppressive therapy in an area where vivax malaria is endemic. Patients suffering from an attack of vivax malaria or having parasitized red blood cells should receive a course of chloroquine phosphate, which quickly destroys the erythrocytic parasites and terminates the paroxysm. Primaquine phosphate tablets should be administered concurrently to eradicate the exoerythrocytic parasites in adults at a dosage of 1 tablet (equivalent to 15 mg base) daily for 14 days.

Primaquine phosphate tablets can be taken with or without food. Administration of primaquine phosphate tablets with food may reduce the incidence of gastrointestinal symptoms.

Contraindications 100 words

CONTRAINDICATIONS Known hypersensitivity reactions to primaquine phosphate, other 8-­aminoquinolones, or to any component in primaquine. Severe glucose-6-phosphate dehydrogenase (G6PD) deficiency (see WARNINGS, Hemolytic Anemia ). Pregnant women (see WARNINGS, Pregnancy ).

Breastfeeding by a lactating woman when the infant is found to be G6PD deficient or if G6PD status is unknown (see WARNINGS, Nursing Mothers ). Because quinacrine hydrochloride appears to potentiate the toxicity of antimalarial compounds which are structurally related to primaquine, the use of quinacrine in patients receiving primaquine is contraindicated. Similarly, primaquine should not be administered to patients who have received quinacrine recently, as toxicity is increased.

⚠️ Warnings ~3 min read

WARNINGS Hemolytic Anemia Hemolytic reactions (moderate to severe) may occur in individuals with G6PD deficiency and in individuals with a family or personal history of favism. Areas of high prevalence of G6PD deficiency are Africa, Southern Europe, Mediterranean region, Middle East, South-East Asia, and Oceania. People from these regions have a greater tendency to develop hemolytic anemia due to a congenital deficiency of erythrocytic G6PD while receiving primaquine and related drugs.

Due to the risk of hemolytic anemia in patients with G6PD deficiency, G6PD testing must be performed before using primaquine. Before initiating treatment, obtain baseline hemoglobin and hematocrit. In case of severe anemia, postpone the G6PD test and decision on treatment with primaquine until recovery.

Due to the limitations of G6PD tests, physicians need to be aware of residual risk of hemolysis and adequate medical support and follow-up to manage hemolytic risk should be available. This is of particular importance in individuals with a personal or family history of hemolytic anemia. Patients with G6PD Deficiency Primaquine is contraindicated in patients with severe G6PD deficiency (see CONTRAINDICATIONS ).

In case of mild to moderate G6PD deficiency, a decision to prescribe primaquine must be based on an assessment of the risks and benefits of using primaquine. If primaquine administration is considered, baseline hematocrit and hemoglobin must be checked before treatment and close hematological monitoring (e.g., at day 3 and 8) is required. Adequate medical support to manage hemolytic risk should be available.

Patients with Unknown G6PD Status When the G6PD status is unknown and G6PD testing is not available, a decision to prescribe primaquine must be based on an assessment of the risks and benefits of using primaquine. Risk factors for G6PD deficiency or favism must be assessed. Baseline hematocrit and hemoglobin must be checked before treatment and close hematological monitoring (e.g., at day 3 and 8) is required.

Adequate medical support to manage hemolytic risk should be available. Patients without G6PD Deficiency In G6PD normal patients it is also advisable to perform routine blood examinations (particularly blood cell counts and hemoglobin determinations) during therapy. Risk of Hemolysis with Other Drugs Avoid the concurrent administration of hemolytic agents in all patients (see CLINICAL PHARMACOLOGY, Drug Interactions ).

Warn patients to discontinue the use of primaquine promptly if signs suggestive of hemolytic anemia occur (such as darkening of the urine, pale skin, shortness of breath, dizziness, and fatigue) and to contact their healthcare professional immediately. Pregnancy Safe usage of primaquine in pregnancy has not been established. Primaquine is contraindicated in pregnant women.

The use of primaquine during pregnancy may cause hemolytic anemia in a G6PD-deficient fetus. Even if a pregnant woman has normal levels of G6PD, the fetus could be G6PD-deficient (see CONTRAINDICATIONS ). Animal data show toxicity to reproduction and embryofetal development.

(See PRECAUTIONS, Animal Pharmacology and/or Animal Toxicology ). Nonclinical data from studies conducted in bacteria and in animals treated with primaquine show evidence of gene mutations and chromosomal/DNA damage, teratogenicity, and injury to embryos and developing fetuses when primaquine is administered to pregnant animals. Inform patients of the potential for adverse genetic and reproductive effects associated with primaquine treatment (see PRECAUTIONS, Carcinogenesis, Mutagenesis, and Impairment of Fertility , and Animal Pharmacology and/or Animal Toxicology ).

Use in Females and Males of Reproductive Potential Pregnancy Testing Sexually active females of reproductive potential should have a pregnancy test prior to starting treatment with primaquine. Contraception Patients should avoid pregnancy during treatment. The use of effective contraception is recommended during t…

🤒 Adverse Reactions 122 words

ADVERSE REACTIONS To report SUSPECTED ADVERSE REACTIONS, please call Ingenus Pharmaceuticals, LLC at 1-877-748-1970 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch Gastrointestinal: Nausea, vomiting, epigastric distress, abdominal cramps. Hematologic: Leukopenia, hemolytic anemia, decreased hemoglobin, methemoglobinemia. Hemolytic anemia occurs commonly in patients with G6PD deficiency and may be severe or fatal in patients with severe G6PD deficiency (see WARNINGS ).

Methemoglobin levels are usually <10%, but methemoglobinemia may be severe in nicotinamide adenine dinucleotide (NADH) methemoglobin reductase deficient individuals or in patients with other risk factors (see PRECAUTIONS ). Leukopenia was observed in patients with rheumatoid arthritis or lupus erythematosus (see PRECAUTIONS ). Cardiac: Cardiac arrhythmia and QT interval prolongation (see PRECAUTIONS , OVERDOSAGE ).

Nervous System: Dizziness. Skin and Soft Tissue: Rash, pruritus.

🔄 Drug Interactions ~1 min read

Drug Interactions Pharmacodynamics Interactions Quinacrine Concurrent use of quinacrine (mepacrine) and primaquine are contraindicated. Increased toxicity was seen when quinacrine was used with pamaquine, another 8-aminoquinoline (see CONTRAINDICATIONS ). Hemolytic Agents and Methemoglobinemia-Inducing Drugs The concurrent administration of hemolytic agents or methemoglobinemia-inducing drugs and primaquine should be avoided (see PRECAUTIONS ).

If the concurrent administration cannot be avoided, close blood monitoring is required. QT Interval Prolonging Drugs The pharmacodynamic interaction potential to prolong the QT interval of the electrocardiogram between primaquine and other drugs that effect cardiac conduction is unknown. If primaquine is used concomitantly with other drugs that prolong the QT interval, close and frequent electrocardiogram monitoring is advised (see PRECAUTIONS , ADVERSE REACTIONS , and OVERDOSAGE ).

Effects of Other Drugs on the Pharmacokinetics of Primaquine Potent CYP2D6 Inhibitors Published clinical and non-clinical reports indicate reduced CYP2D6 activity may decrease the formation of active metabolites of primaquine, which may reduce antimalarial efficacy of primaquine. Where possible, consider alternative medications that are not potent CYP2D6 inhibitors. If concurrent use with primaquine is necessary, increase monitoring for possible relapse.

Effects of Primaquine on the Pharmacokinetics of Other Drugs CYP1A2 Substrates Published clinical and non-clinical reports indicate primaquine inhibits CYP1A2 enzyme activity and thus may lead to increased exposure of CYP1A2 substrate drugs (e.g., duloxetine, alosetron, theophylline and tizanidine) when co-administered with primaquine. Since data are limited, no predictions can be made regarding the extent of the impact on CYP1A2 substrate drug exposures. Increase monitoring for adverse reactions associated with the CYP1A2 substrate drug when concurrently administered with primaquine.

P-gp Substrates with Narrow Therapeutic Index In vitro observations suggest that primaquine inhibits the P-gp membrane transporter. Therefore, there is a potential for increased concentrations of drugs that are P-gp substrates when co-administered with primaquine. Increase monitoring for adverse reactions associated with narrow therapeutic index drugs that are P-gp substrates (e.g., digoxin and dabigatran) when concomitantly administered with primaquine.

🧒 Pediatric Use 43 words

Pediatric Use Safety and effectiveness in pediatric patients have not been established. Primaquine is contraindicated in breastfeeding women when the infant is found to be G6PD deficient or the G6PD status of the infant is unknown (see CONTRAINDICATIONS and WARNINGS, Nursing Mothers ).

🧓 Geriatric Use 82 words

Geriatric Use Clinical studies of primaquine did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

🆘 Overdosage 82 words

OVERDOSAGE Signs and symptoms Symptoms of overdosage of primaquine phosphate include abdominal cramps, vomiting, burning epigastric distress, central nervous system disturbances including headache, insomnia, and cardiovascular disturbances, including cardiac arrhythmia and QT interval prolongation, methemoglobinemia (indicated by cyanosis), moderate leukocytosis or leukopenia, granulocytopenia, and anemia. Acute hemolysis may occur with particular severity in G6PD deficient patients. Management Treatment of overdosage consists of institution of appropriate symptomatic and/or supportive therapy.

Consider contacting a poison center or a medical toxicologist for overdosage management recommendations.

🧬 Clinical Pharmacology ~3 min read

CLINICAL PHARMACOLOGY Microbiology Mechanism of Action Primaquine phosphate is an 8-aminoquinoline antimalarial drug. The mechanism of action has not been fully established. The major assumptions are an inhibition of the mitochondrial system of dormant parasites, and an oxidative stress generated through reactive metabolites in infected cells.

In humans, primaquine phosphate activity is probably related to hydroxylated metabolites generated intrahepatically by CYP2D6. Antimicrobial Activity Primaquine phosphate is active against the dormant liver forms of P.vivax , namely hypnozoites, as well as exoerythrocytic stages of the parasite. Thereby, it prevents the development of the blood (erythrocytic) forms of the parasite which are responsible for relapses in vivax malaria.

Primaquine phosphate is also active against gametocytes of Plasmodium falciparum . Resistance Development of resistance to primaquine phosphate in Plasmodium species has not been well studied. Pharmacokinetics Following single oral dosing, the C max and AUC of primaquine increase approximately dose-proportionally over a primaquine base dose range of 15 mg to 45 mg (3 times the approved dose).

The pharmacokinetic parameters and properties of primaquine and carboxyprimaquine (main circulating metabolite not expected to be active) in patients with P. vivax malaria following Oral Administration of primaquine are provided in TABLE 1. TABLE 1: Summary of Pharmacokinetic Parameters and Properties (Mean ± SD) in Patients with P. vivax malaria. PK Parameter 15 mg once daily in adult patients (18 years of age and older) with P. vivax malaria, unless otherwise specified Day Primaquine Carboxyprimaquine C max (ng/mL) 1 50.7 ± 21.2 291 ± 52 C max (ng/mL) 14 49.7 ± 14.4 432 ±112 AUC or AUC 0-24 (μg/mL*h) AUC for primaquine, AUC 0-24 for carboxyprimaquine 1 0.48 ± 0.26 5.15 ±

1.01AUC or AUC 0-24 (μg/mL*h) † 14 0.49 ± 0.19 7.24 ±

1.82Primaquine Absorption Bioavailability Healthy participants >70 % T max 2.3 ± 1.1 hours Effect of food on primaquine (relative to fasting) Values refer to increase in mean systemic exposure with bread and butter: 82% fat, ~28g fat after single dose of 30 mg primaquine in healthy participants Geometric mean [95% confidence interval] ↑ 14% [3, 27] (AUC); ↑ 26% [12, 40] (C max ) Distribution % Bound to human plasma proteins 74% (mainly to alpha 1 acid glycoprotein) Volume of distribution (V) IV dose administration of [ 14 C]-primaquine in healthy participants 243 ± 69 L Metabolism Metabolic pathways -Oxidative deamination, MAO-A -Hydroxylation of the quinoline ring, CYP2D6 -Direct conjugations Elimination Major route of elimination Metabolism Apparent Clearance (CL/F) 37.6 ±

14.7L/hr Mean terminal half-life (t 1/2 ) The mean terminal half-life of carboxyprimaquine is approximately 22 hours 5.6 ± 1.0 hours % of dose excreted in urine The main circulating metabolite, carboxyprimaquine is subjected to further metabolism and not eliminated through urine , Oral administration of [ 14 C]-primaquine in healthy participants; no data in feces 64%, (including 3.6% of primaquine, the remnant being metabolites other than carboxyprimaquine) C max =maximum plasma concentration; AUC=area under the plasma concentration-time curve from time zero up to infinity; MAO-A = monoamine oxidase A Specific Populations Gender and ethnicity No gender nor ethnicity effect has been evidenced in studies conducted to date.

Elderly patients There are no pharmacokinetics studies in patients older than 52 years of age. Hepatic impairment Single dose pharmacokinetics study performed in patients with mild or moderate hepatic impairment indicate that only moderate hepatic dysfunction impacted significantly the PK of primaquine with a 3-fold lower primaquine C max in patients with moderate hepatic dysfunction as compared to healthy subjects. The primaquine AUC was not significantly modified.

No data are available after repeated dosing in patients with hepatic impairment. It is not kno…

📦 How Supplied / Storage and Handling 78 words

HOW SUPPLIED Primaquine phosphate tablets, USP are supplied as orange colored, round, biconvex, film-coated tablets of 26.3 mg (= 15 mg base), debossed with a "059" on one side and plain on the other side. Available in bottles of 100 tablets (NDC 50742-191-01) and bottles of 500 tablets (NDC 50742-191-05) Store at 25°C (77°F); excursions permitted to 15°C – 30°C (59°F – 86°F) [see USP Controlled Room Temperature] Dispense in tight, light-resistant container as defined in the USP/NF.

📋 Description 99 words

DESCRIPTION Primaquine phosphate is 8-[(4-amino-1-methylbutyl) amino]-6-methoxyquinoline phosphate, a synthetic compound with potent antimalarial activity. The molecular formula of primaquine phosphate is C 15 H 21 N 3 O·2H 3 PO 4 and its molecular weight is 455.34. The structural formula of primaquine phosphate is: Figure 1: Primaquine phosphate structure.

Each Primaquine phosphate tablet, USP contains 26.3 mg of primaquine phosphate (equivalent to 15 mg of primaquine base). The dosage is customarily expressed in terms of the base. Inactive Ingredients: Hypromellose, Lactose Monohydrate, Magnesium Stearate, Microcrystalline Cellulose, Triacetin, Pregelatinized Starch, FD&C Yellow#6/Sunset Yellow FCF Aluminum Lake, Talc, Titanium Dioxide.

Structure

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.