Primaquine Phosphate 15 mg Tablet, 100-count
🆔 Identity & classification
Where does this data come from?
🏷️ RxNorm drug class
This medicine belongs to the Antimalarial class.
Where does this data come from?
🏭 Manufacturer & labeler
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🩺 Clinical
- 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?
Patient education
Supplement & herbal interactions
Some supplements/herbs that may interact with Primaquine Phosphate — tap one for details:
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🧪 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.
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IACT rows and label-wide narrative are kept separate; availability and product-level specificity depend on the submitted label.Inactive ingredient FAQ
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💲 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 system | Per ea | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | $1.964 | $196.39 / 100 tablets |
| Medicaid paysCMS SDUD · 12 mo | $1.67 | $166.99 / 100 tablets |
| Medicare drug plans payPart D · Q2 2026 | $1.96 | $195.92 / 100 tablets |
Where does this data come from?
🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Primaquine Phosphate 15 mg 00024-1596-01 | Sanofi-Aventis | 100 tablets | $1.964 | AB | Availability likely | — |
| Primaquine Phosphate 15 mgthis 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 mg 50742-0191-01 | Ingenus | 100 tablets | — | AB | FDA listed | — |
Where does this data come from?
⏳ Availability & generic status
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?
🗺️ Medicaid utilization & spend
📊 Medicare Part D spend CMS · PART D · 2026 (Q1)
📦 Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Status |
|---|---|---|---|
| 76385-0102-01 You're viewing this | 100 TABLET in 1 BOTTLE (76385-102-01) | 2014-08-01 | Active |
📄 Full prescribing information FDA SPL
🎯 Indications and Usage ▾
INDICATIONS AND USAGE Primaquine phosphate Tablets are indicated for the radical cure (prevention of relapse) of vivax malaria.
⏱️ Dosage and Administration ▾
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 ▾
CONTRAINDICATIONS Known hypersensitivity reactions to primaquine phosphate, other 8-aminoquinolones, or to any component in Primaquine phosphate Tablets. 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 phosphate Tablets is contraindicated. Similarly, Primaquine phosphate Tablets should not be administered to patients who have received quinacrine recently, as toxicity is increased.
⚠️ Warnings ▾
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 phosphate Tablets are 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 phosphate Tablets 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 phosphate Tablets in pregnancy has not been established. Primaquine is contraindicated in pregnant women.
The use of Primaquine phosphate Tablets 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…
🤒 Adverse Reactions ▾
ADVERSE REACTIONS 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 ▾
Drug Interactions Pharmacodynamics Interactions Quinacrine Concurrent use of quinacrine (mepacrine) and Primaquine phosphate Tablets 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 phosphate Tablets and other drugs that effect cardiac conduction is unknown. If Primaquine phosphate Tablets are 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 Strong 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 phosphate Tablets (see CLINICAL PHARMACOLOGY , Pharmacogenomics ). Where possible, consider alternative medications that are not strong CYP2D6 inhibitors. If concurrent use with Primaquine phosphate Tablets is necessary, increase monitoring for possible relapse.
Concomitant use of an MAO-A inhibitor in patients with reduced or absent CYP2D6 activity (e.g., strong CYP2D6 inhibitor, CYP2D6 intermediate or poor metabolizer) is expected to increase primaquine exposure which may increase the risk of adverse reactions (see CLINICAL PHARMACOLOGY , Pharmacogenomics ). Defer initiation of MAO-A inhibitor therapy or consider alternative drug therapy in patients with reduced or absent CYP2D6 activity until primaquine treatment is completed. If concurrent use with Primaquine phosphate Tablets is necessary, increase patient monitoring for potential adverse reactions (see PRECAUTIONS ).
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 phosphate Tablets. 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 phosphate tablets.
CYP3A4 Substrates Refer to the Prescribing Information for a CYP3A substrate where minimal concentration changes may lead to serious adverse reactions (e.g. rivaroxaban, calcineurin inhibitors, ergot derivatives, tyrosine kinase inhibitors) for the recommended dosage modification and/or monitoring. Published clinical reports indicate primaquine may inhibit CYP3A4 enzyme activity and thus may lead to increased exposure of oral CYP3A4 substrate drugs when co-administered with Primaquine phosphate Tablets. Since data are limited, no predictions can be made regarding the extent of the impact on oral CYP3A4 substrate drug exposures.
Increase monitoring for adverse reactions associated with CYP3A4 substrate drugs that prolong the QT interval (e.g., pimozide) or where minimal concentration changes may lead to serious adverse reactions when concurrently administered with Primaquine phosphate Tablets . P-gp Substrates Refer to the Prescribing Information for a P-gp substrate where minimal concentration changes may lead to serious adverse reactions (e.g., digoxin and dabigatran) for the recommended dosage modification and/or monitoring. In vitro observations suggest that primaquine inhibits the P-gp membr…
🧓 Geriatric Use ▾
Geriatric Use Clinical studies of Primaquine phosphate Tablets 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 ▾
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 ▾
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 phosphate Tablets are provided in TABLE 1. TABLE 1: Summary of Pharmacokinetic Parameters and Properties (Mean ± SD) in Patients with P. vivax malaria. PK Parameter a 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) b 1 0.48 ± 0.26 5.15 ±
1.01AUC or AUC 0-24 (μg/mL*h) b 14 0.49 ± 0.19 7.24 ±
1.82Primaquine Absorption Bioavailability c >70 % T max 2.3 ± 1.1 hours Effect of food on Primaquine Phosphate Tablet (relative to fasting) d 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) e 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 ) f 5.6 ± 1.0 hours % of dose excreted in urine g, h 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 a 15 mg once daily in adult patients (18 years of age and older) with P. vivax malaria, unless otherwise specified b AUC for primaquine, AUC 0-24 for carboxyprimaquine c Healthy participants d 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 e IV dose administration of [ 14 C]-primaquine in healthy participants f The mean terminal half-life of carboxyprimaquine is approximately 22 hours g Oral administration of [ 14 C]-primaquine in healthy participants; no data in feces h The main circulating metabolite, carboxyprimaquine is subjected to further metabolism and not eliminated through urine 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 r…
📦 How Supplied / Storage and Handling ▾
HOW SUPPLIED Primaquine phosphate Tablets USP are solid oral formulation round purple tablet debossed "BY4" available in 26.3 mg (=15 mg base) and 100 count. Available in bottles of 100 tablets. (NDC 76385-102-01) Store at 25° C (77° F); excursions permitted to 15° - 30° C (59° - 86° F) [see USP Controlled Room Temperature]. Dispense in tight, light-resistant container as defined in the USP/NF.
📋 Description ▾
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 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: Microcrystalline Cellulose, Pregelatinized Starch, Lactose Monohydrate, Magnesium Stearate, Purified Water, Hypromellose, Opadry Purple, Titanium Dioxide, Macrogol/PEG, FD&C Red #40 and FD&C Blue #2. structure