Version July 2025
Note: Screen for G6PD deficiency prior to initiating treatment (Ref). Dosage expressed as mg of base (15 mg base = 26.3 mg primaquine phosphate):
Malaria, uncomplicated; relapse prevention (radical cure) ( P. vivax or P. ovale) : Limited data available:
Patients without G6PD-deficiency:
14-Day Regimen:
Infants, Children, and Adolescents: Note: Guideline-recommended regimen (Ref):
<70 kg: Oral: 0.5 mg base/kg/dose once daily for 14 days; maximum dose: 30 mg base/dose; must be used in combination with appropriate acute antimalarial treatment; consult guidelines to determine the appropriate agent (Ref).
≥70 kg: Oral: 30 mg base/day once daily to complete a total course of 6 mg base/kg (duration is the number of days it takes to complete total dose of 6 mg base/kg divided into 30 mg doses); must be used in combination with appropriate acute antimalarial treatment; consult guidelines to determine the appropriate agent (Ref).
7-Day Regimen: Note: This regimen has only been studied in patients with P. vivax.
Infants ≥6 months weighing ≥5 kg, Children, and Adolescents: Limited data available: Oral: 1 mg base/kg daily for 7 days; dosing based on 2 randomized noninferiority trials in which primaquine was given concomitantly with chloroquine or dihydroartemisinin-piperaquine for the treatment of uncomplicated P. vivax monoinfection; primaquine was administered for either 7 days at a dose of 1 mg/kg/day or at the same total dose divided over 14 days; malaria recurrence was similar between groups and gastrointestinal symptoms were more common in patients who received the 7-day regimen (Ref).
Patients with G6PD-deficiency:
Note: Recommended for patients with mild to moderate or intermediate G6PD deficiency; if patient has more severe G6PD deficiency or is not expected to tolerate primaquine, see guidelines for treatment options (Ref). Must be used in combination with appropriate acute antimalarial treatment; consult guidelines to determine the appropriate agents (Ref).
Infants ≥6 months, Children, and Adolescents: Limited data available: Oral: 0.75 mg base/kg/dose once weekly for 8 weeks under close medical supervision and monitoring for hemolysis; maximum dose: 45 mg base/dose (Ref).
Malaria, prophylaxis: Limited data available:
Primary prophylaxis for short-duration travel (<6 months) for travelers going to areas with primarily P. vivax: Infants, Children, and Adolescents (independent of HIV status): Oral: 0.5 mg base/kg/dose once daily; maximum dose: 30 mg base/dose; initiate 1 to 2 days prior to travel, and continue while in the area with malaria risk and for 7 days after departure(Ref).
Terminal prophylaxis (presumptive antirelapse therapy [PART]): Infants, Children, and Adolescents (independent of HIV status): Oral: 0.5 mg base/kg/dose once daily for 14 days after departure from malaria-endemic area; maximum dose: 30 mg base/dose (Ref).
Malaria, reduction in transmissibility in low transmission endemic areas (P. falciparum): Limited data available:
Infants ≥6 months, Children, and Adolescents: Oral: 0.25 mg base/kg as a single dose on the first day of malaria treatment, in addition to recommended malaria therapy (Ref). Note: G6PD testing is not required for single dose.
Pneumocystis jirovecii pneumonia (PCP), treatment (alternative) (HIV-exposed/-infected patients): Limited data available:
Infants and Children (doses extrapolated from use in other indications): Mild to moderate disease: Oral: 0.3 mg base/kg/dose once daily for 21 days in combination with clindamycin; maximum dose: 30 mg base/dose (Ref).
Adolescents: Oral: 30 mg base once daily for 21 days in combination with clindamycin (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
There are no dosage adjustments provided in the manufacturer's labeling.
There are no dosage adjustments provided in the manufacturer's labeling.
(For additional information see "Primaquine: Drug information")
Dosage guidance:
Dose: Dosage expressed as mg of base (15 mg base = 26.3 mg primaquine phosphate).
Safety: Screen for G6PD deficiency prior to initiating treatment.
Malaria:
Treatment (antirelapse therapy/radical cure), P. vivax or P. ovale malaria:
CDC recommendations: Oral: 30 mg once daily for 14 days in combination with another appropriate antimalarial agent; in patients weighing ≥70 kg, adjust to a total dose of 6 mg/kg, administered in daily doses of 30 mg once daily for the number of days required to complete the total calculated dose. For patients with intermediate G6PD activity, may consider 45 mg once weekly for 8 weeks, with close monitoring for hemolysis (use only after consultation with an infectious disease/tropical medicine expert) (Ref).
WHO recommendations:
Temperate strains: Oral: 0.25 mg/kg once daily for 14 days or 0.5 mg/kg once daily for 7 days. Total recommended dose: 3.5 mg/kg given over 7 or 14 days (Ref).
Tropical, frequent-relapsing P. vivax: Oral: 0.5 mg/kg (maximum daily dose: 30 mg) once daily for 14 days. Total recommended dose: 7 mg/kg given over 14 days; in patients ≥70 kg, extend treatment duration to achieve total recommended dose without exceeding the maximum daily dose (Ref).
Patients with mild-to-moderate G6PD deficiency: Oral: 0.75 mg/kg once weekly for 8 weeks (Ref).
Prophylaxis (off-label use):
Primary prophylaxis: Oral: 30 mg once daily; start 1 to 2 days prior to travel and continue while in the malaria-endemic area and for 7 days after departure from the area (Ref).
Terminal prophylaxis (presumptive antirelapse therapy): Note: For patients who had prolonged exposure to ≥1 species of relapsing malaria (eg, P. vivax, P. ovale). Presumptive antirelapse therapy is not needed if primaquine or tafenoquine is taken for primary prophylaxis (Ref).
Oral: 30 mg once daily for 14 days after leaving malaria-endemic area, administered concurrently with primary prophylaxis medication; terminal prophylaxis start date is dependent on agent used for primary prophylaxis (Ref).
Pneumocystis pneumonia, treatment (alternative agent) (off-label use): Oral: 30 mg once daily in combination with clindamycin for 21 days (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
There are no dosage adjustments provided in the manufacturer’s labeling (limited data); monitor for efficacy and adverse reactions, especially in patients with severe impairment.
There are no dosage adjustments provided in the manufacturer’s labeling (limited data); monitor for efficacy and adverse reactions, especially in patients with severe impairment.
The following adverse drug reactions are derived from product labeling unless otherwise specified.
Frequency not defined:
Cardiovascular: Cardiac arrhythmia, prolonged QT interval on ECG
Dermatologic: Pruritus, skin rash
Gastrointestinal: Abdominal cramps
Hematologic & oncologic: Leukopenia
Postmarketing:
Gastrointestinal: Epigastric distress (Kheng 2015), nausea (Kheng 2015), vomiting (Kheng 2015)
Hematologic & oncologic: Anemia (Kheng 2015), hemolytic anemia (in patients with glucose-6-phosphate dehydrogenase deficiency) (Ashley 2014), methemoglobinemia (Ashley 2014)
Nervous: Dizziness (Kheng 2015)
Hypersensitivity to primaquine, other 8-aminoquinolines, or any component of the formulation; severe G6PD deficiency; pregnancy; breastfeeding when the infant is found to be G6PD deficient or if the G6PD status of the infant is unknown; concurrent or recent use of quinacrine.
Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Canadian labeling: Additional contraindications (not in US labeling): Hypersensitivity to primaquine or any component of the formulation.
Concerns related to adverse effects:
• Cardiovascular effects: May cause QT prolongation.
• Hematologic effects: Hemolytic anemia, methemoglobinemia, and leukopenia have been associated with primaquine use; do not exceed recommended dosage and duration. Immediately discontinue if marked darkening of the urine or sudden decrease in hemoglobin concentration or leukocyte count occurs.
Disease-related concerns:
• G6PD deficiency: Moderate to severe hemolytic reactions may occur in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency and personal or familial history of favism. Geographic regions with a high prevalence of G6PD deficiency (eg, Africa, southern Europe, Mediterranean region, Middle East, southeast Asia, Oceania) are associated with a higher incidence of hemolytic anemia. Assess benefits/risks of treatment when considering use in patients with mild to moderate G6PD deficiency or those patients whose G6PD status is unknown and testing is not available. Also assess risk factors for G6PD deficiency or favism in patients with unknown G6PD status. Immediately discontinue treatment if signs of hemolytic anemia occur.
• Methemoglobinemia: Methemoglobinemia may occur in patients without risk factors; patients who are deficient in nicotinamide adenine dinucleotide (NADH), methemoglobin reductase, or treated with methemoglobinemia-inducing drugs may experience severe methemoglobinemia.
Dosage form specific issues:
• Polysorbate 80: Some dosage forms may contain polysorbate 80 (also known as Tweens). Hypersensitivity reactions, usually a delayed reaction, have been reported following exposure to pharmaceutical products containing polysorbate 80 in certain individuals (Isaksson 2002; Lucente 2000; Shelley 1995). Thrombocytopenia, ascites, pulmonary deterioration, and renal and hepatic failure have been reported in premature neonates after receiving parenteral products containing polysorbate 80 (Alade 1986; CDC 1984). See manufacturer's labeling.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, Oral, as phosphate:
Generic: 26.3 mg (equivalent to primaquine base 15 mg)
Yes
Tablets (Primaquine Phosphate Oral)
26.3 (15 Base) mg (per each): $1.80 - $2.46
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, Oral, as phosphate:
Generic: 26.3 mg (equivalent to primaquine base 15 mg)
6 mg base/5 mL Oral Suspension
A 6 mg base/5 mL oral suspension may be made using tablets. Crush ten 15 mg base tablets and reduce to a fine powder. In small amounts, add a total of 10 mL Carboxymethylcellulose 1.5% and mix to a uniform paste; mix while adding Simple Syrup, NF to almost 125 mL; transfer to a calibrated bottle, rinse mortar with vehicle, and add quantity of vehicle sufficient to make 125 mL. Label "shake well" and "refrigerate". Stable 7 days.
Oral: Administer with meals to decrease adverse GI effects (Ref). Tablet may be crushed and mixed with a small amount of applesauce, chocolate syrup, or jelly (Ref).
Oral: Administer with food to decrease adverse GI effects (Ref). Tablet may be crushed and mixed with a small amount of applesauce, chocolate syrup, or jelly (Ref).
Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F). Protect from light.
For the radical cure (prevention of relapse) of vivax malaria (Plasmodium vivax) (FDA approved in adults); has also been used for radical cure (relapse prevention) of Plasmodium ovale, prevention of malaria (in areas with primarily P. vivax), reduction of Plasmodium falciparum malaria transmission in low-transmission endemic areas, and treatment of Pneumocystis jirovecii pneumonia.
Primaquine may be confused with primidone
The Institute for Safe Medication Practices (ISMP) includes this medication among its list of drugs (contraindicated in pregnancy) which have a heightened risk of causing significant patient harm when used in error (High-Alert Medications in Community/Ambulatory Care Settings).
Substrate of CYP2D6 (Minor), CYP3A4 (Minor); Note: Assignment of Major/Minor substrate status based on clinically relevant drug interaction potential;
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program
Artemether and Lumefantrine: Antimalarial Agents may increase adverse/toxic effects of Artemether and Lumefantrine. Management: Artemether/lumefantrine (combination product) should not be used with other antimalarials unless there is no other treatment option. If combined, monitor patients for increased toxicities of both agents, including QTc interval prolongation. Risk D: Consider Therapy Modification
Artesunate: May increase QTc-prolonging effects of Primaquine. Artesunate may increase serum concentration of Primaquine. Risk C: Monitor
Chloroquine: May increase serum concentration of Primaquine. Risk C: Monitor
Chlorprothixene: May increase QTc-prolonging effects of Antimalarial Agents. Risk X: Avoid
CYP1A2 Substrates (High risk with Inhibitors): Primaquine may increase serum concentration of CYP1A2 Substrates (High risk with Inhibitors). Risk C: Monitor
CYP2D6 Inhibitors (Strong): May decrease therapeutic effects of Primaquine. CYP2D6 Inhibitors (Strong) may decrease active metabolite exposure of Primaquine. Management: Consider alternatives to the combination of primaquine and strong CYP2D6 inhibitors. If concomitant use is necessary, monitor for signs and symptoms of possible primaquine treatment failure. Risk D: Consider Therapy Modification
Dapsone (Systemic): Antimalarial Agents may increase adverse/toxic effects of Dapsone (Systemic). Specifically, concomitant use of antimalarial agents with dapsone may increase the risk of hemolytic reactions. Dapsone (Systemic) may increase adverse/toxic effects of Antimalarial Agents. Specifically, concomitant use of dapsone with antimalarial agents may increase the risk for hemolytic reactions. Management: Closely monitor patients for signs/symptoms of hemolytic reactions with concomitant use of dapsone and antimalarial agents, particularly in patients deficient in glucose-6-phosphate dehydrogenase (G6PD), methemoglobin reductase, or with hemoglobin M. Risk D: Consider Therapy Modification
Dapsone (Topical): Antimalarial Agents may increase adverse/toxic effects of Dapsone (Topical). Specifically, the risk of hemolytic reactions may be increased. Management: Consider avoidance of this combination when possible. If combined, closely monitor for signs/symptoms of hemolytic reactions. Patients with glucose-6-phosphate dehydrogenase deficiency may be at particularly high risk for adverse hematologic effects. Risk D: Consider Therapy Modification
Haloperidol: QT-prolonging Agents (Indeterminate Risk - Caution) may increase QTc-prolonging effects of Haloperidol. Risk C: Monitor
Local Anesthetics: Methemoglobinemia Associated Agents may increase adverse/toxic effects of Local Anesthetics. Specifically, the risk for methemoglobinemia may be increased. Risk C: Monitor
Mefloquine: Aminoquinolines (Antimalarial) may increase adverse/toxic effects of Mefloquine. Specifically, the risk for QTc-prolongation and the risk for convulsions may be increased. Management: Avoid concurrent use, and delay administration of mefloquine until at least 12 hours after the last dose of an aminoquinoline antimalarial. Risk X: Avoid
Methemoglobinemia Associated Agents: May increase adverse/toxic effects of Primaquine. Specifically, the risk for methemoglobinemia may be increased. Management: Avoid concomitant use of primaquine and other drugs that are associated with methemoglobinemia when possible. If combined, monitor methemoglobin levels closely. Risk D: Consider Therapy Modification
P-glycoprotein/ABCB1 Substrates (Narrow Therapeutic Index/Sensitive with Inhibitors): Primaquine may increase serum concentration of P-glycoprotein/ABCB1 Substrates (Narrow Therapeutic Index/Sensitive with Inhibitors). Risk C: Monitor
QT-prolonging Agents (Highest Risk): QT-prolonging Agents (Indeterminate Risk - Caution) may increase QTc-prolonging effects of QT-prolonging Agents (Highest Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Rabies Vaccine: Aminoquinolines (Antimalarial) may decrease therapeutic effects of Rabies Vaccine. Management: If coadministration is unavoidable during rabies post-exposure vaccination, give a 5th dose of the rabies vaccine. If coadministration is unavoidable during rabies pre-exposure vaccination, ensure antibody titers are greater than or equal to 0.5 IU/mL. Risk D: Consider Therapy Modification
Pregnancy testing is recommended prior to use in patients who may become pregnant. Patients who could become pregnant should use effective contraception during therapy and until the next menses following discontinuation of treatment. Patients with partners who could become pregnant should use condoms during therapy and for 3 months after treatment is discontinued.
Patients who are likely to become pregnant are advised to avoid travel to malaria-risk areas. When travel is unavoidable, precautions should be taken to avoid mosquito bites and effective prophylactic medications should be used. Medications considered acceptable for the prophylaxis of malaria during pregnancy may be used in patients trying to conceive. Primaquine is contraindicated for use in pregnant patients (CDC 2023; CDC Yellow Book 2024).
Malaria infection in pregnant patients may be more severe than in nonpregnant patients and has a high risk of maternal and perinatal morbidity and mortality. Malaria infection during pregnancy can lead to miscarriage, premature delivery, low birth weight, congenital infection, and/or perinatal death. Therefore, pregnant persons are advised to avoid travel to malaria-risk areas. When travel is unavoidable, pregnant persons should take precautions to avoid mosquito bites and use effective prophylactic medications (CDC 2023; CDC Yellow Book 2024).
Because primaquine may cause acute hemolytic anemia in a fetus with glucose-6-phosphate dehydrogenase deficiency, use is contraindicated during pregnancy (CDC 2023; CDC Yellow Book 2024). Consult current CDC guidelines for the treatment of malaria during pregnancy.
Screen for G6PD deficiency prior to initiating treatment (CDC 2019). Pregnancy test prior to therapy in sexually-active females. CBC (baseline and periodic), visual color check of urine (periodic), glucose; ECG (in patients at risk for QT prolongation). If hemolysis is suspected, monitor CBC, haptoglobin, reticulocyte count, peripheral smear, liver function tests (Frank 2005).
Primaquine is an antiprotozoal agent active against exoerythrocytic stages of Plasmodium ovale and P. vivax, also active against the primary exoerythrocytic stages of P. falciparum and gametocytes of Plasmodia; disrupts mitochondria and binds to DNA
Bioavailability: >70%.
Distribution: Vd: 243 ± 69 L.
Protein binding: 74% (primarily to alpha-1 acid glycoprotein).
Metabolism: Hepatic via MAO type A oxidative deamination and CYP2D6 to carboxyprimaquine (active); also undergoes direct conjugations.
Half-life elimination: 5.6 ± 1 hours.
Time to peak, serum: 2.3 ± 1.1 hours.
Excretion: Urine (64%; 3.6% as unchanged drug).
