Treatment of malaria caused by Plasmodium vivax or P. ovale. Provides a radical cure to prevent relapse of malaria caused by these Plasmodium. Not usually active against asexual erythrocytic forms of Plasmodium; a regimen that includes a blood schizonticidal agent (e.g., chloroquine, quinine with doxycycline or tetracycline) always is given in conjunction with primaquine for treatment of P. ovale or P. vivaxmalaria.
Terminal malaria prophylaxis in travelers who received chloroquine or other suitable antimalarials for prevention of malaria but are returning from areas where P. vivax or P. ovale are endemic. If primaquine prophylaxis is not used for terminal prophylaxis in individuals who may have been exposed to P. ovale or P. vivax malaria, delayed primary attacks or relapse caused by these Plasmodium can occur up to 4 years later.
Alternative for prevention of malaria† (primary prophylaxis) in travelers, including travelers to areas with chloroquine-resistant P. falciparum. Should be used for primary prophylaxis only in rare circumstances when the drugs of choice for malaria prevention (chloroquine, mefloquine, doxycycline, fixed combination of atovaquone and proguanil) cannot be used and only after consultation with malaria experts such as those available from the CDC Malaria Epidemiology Branch (770-488-7788).
Assistance with diagnosis or treatment of malaria available from CDC Malaria Epidemiology Branch by contacting CDC Malaria Hotline at 770-488-7788 from 8:00 a.m. to 4:30 p.m. Eastern Standard Time or CDC Emergency Operation Center at 770-488-7100 after hours, on weekends, and holidays.
Treament of Pneumocystis jiroveci (formerly Pneumocystis carinii) pneumonia† (PCP); used in conjunction with clindamycin. Designated an orphan drug by FDA for use in this condition.
Co-trimoxazole is initial drug of choice for treatment in most adults, adolescents, and children, including HIV-infected patients; a regimen of clindamycin and primaquine is an alternative for adults or adolescents with mild to moderately severe PCP who had an inadequate response to co-trimoxazole or when co-trimoxazole is contraindicated or not tolerated.
Clindamycin in conjunction with primaquine has been used as an alternative for long-term suppressive or chronic maintenance therapy (secondary prophylaxis) of PCP†, but USPHS/IDSA states the regimen should only be considered for primary or secondary prophylaxis of PCP in unusual situations when the usually recommended agents (co-trimoxazole, dapsone, dapsone with pyrimethamine and leucovorin, aerosolized pentamidine, atovaquone) cannot be used.
Dosage and Administration
General
Prior to use for treatment or prevention of malaria, CDC recommends appropriate laboratory tests to rule out glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and recommends consultation with CDC Malaria Hotline (770-488-7788) or other experts prior to use for primary prophylaxis of malaria†.
Administration
Oral Administration
Administer orally as a single dose at the same time each day.
Administration with a meal may decrease adverse GI effects.
Dosage
Available as primaquine phosphate; dosage usually expressed in terms of primaquine. Each 26.3 mg of primaquine phosphate is equivalent to 15 mg of primaquine.
Pediatric Patients
Malaria
Radical Cure and Prevention of Delayed Attacks or Relapse of P. ovale or P. vivax Malaria
Oral
0.6 mg/kg (1 mg/kg of primaquine phosphate) once daily for 14 days.
Terminal Prophylaxis to Prevent Delayed Primary Attacks or Relapse of P. ovale or P. vivax Malaria
Oral
0.6 mg/kg (1 mg/kg of primaquine phosphate) once daily for 14 days.
When used in individuals who have left areas where P. ovale or P. vivax are endemic, administer primaquine during the last 2 weeks of, or immediately following, primary prophylaxis with chloroquine, doxycycline, or mefloquine. If fixed-combination of atovaquone and proguanil is used for primary prophylaxis, administer primaquine either during the last 7 days of atovaquone and proguanil prophylaxis and then for an additional 7 days, or alternatively, for 14 days after atovaquone and proguanil prophylaxis is discontinued.
Primary Prophylaxis of Malaria (Including Chloroquine-resistant P. falciparum Malaria)
Oral
0.6 mg/kg (1 mg/kg of primaquine phosphate) once daily. Initiate prophylaxis 1–2 days prior to entering a malarious area and continue for 3–7 days after leaving the area.†
Adults
Malaria
Radical Cure and Prevention of Delayed Attacks or Relapse of P. ovale or P. vivax Malaria
Oral
30 mg of primaquine (52.6 mg of primaquine phosphate) once daily for 14 days recommended by CDC and others. Manufacturer recommends 15 mg of primaquine (26.3 mg of primaquine phosphate) once daily for 14 days.
As an alternative to the daily regimen or in patients with borderline G-6-PD deficiency, CDC recommends 45 mg of primaquine (79 mg of primaquine phosphate) once weekly for 8 weeks. Consultation with an expert in infectious disease and/or tropical medicine is recommended if this alternative regimen is considered for individuals with borderline G-6-PD deficiency. (See Hematologic Effects under Cautions.)
Terminal Prophylaxis to Prevent Delayed Primary Attacks or Relapse of P. ovale or P. vivax Malaria
Oral
30 mg of primaquine (52.6 mg of primaquine phosphate) once daily for 14 days recommended by CDC and others. Manufacturer recommends 15 mg of primaquine (26.3 mg of primaquine phosphate) once daily for 14 days.
When used in individuals who have left areas where P. ovale or P. vivax are endemic, administer primaquine during the last 2 weeks of, or immediately following, prophylaxis with chloroquine, doxycycline, or mefloquine. If the fixed-combination atovaquone and proguanil is used for primary prophylaxis, administer primaquine either during the last 7 days of atovaquone and proguanil prophylaxis and then for an additional 7 days, or alternatively, for 14 days after atovaquone and proguanil prophylaxis is discontinued.
Primary Prophylaxis of Malaria (Including Chloroquine-resistant P. falciparum Malaria)
Oral
30 mg of primaquine once daily. Initiate prophylaxis 1–2 days prior to entering a malarious area and continue for 3–7 days after leaving the area.†
15–30 mg of primaquine once daily for 21 days; used in conjunction with IV clindamycin (600–900 mg every 6–8 hours) or oral clindamycin (300–450 mg orally every 6–8 hours) given for 21 days.†
Prescribing Limits
Pediatric Patients
Pediatric dosage should not exceed usual adult dosage.
Patients receiving other potentially hemolytic drugs or agents capable of depressing the myeloid elements of bone marrow.
CDC states that use is contraindicated in individuals with G-6-PD deficiency, in pregnant women, and during lactation (unless the breast-fed infant has been determined not to have G-6-PD deficiency).
Warnings/Precautions
Warnings
Hematologic Effects
Acute hemolytic anemia, possibly fatal, may occur if used in patients with G-6-PD deficiency. CDC recommends that appropriate laboratory testing be done to rule out G-6-PD deficiency before initiating primaquineprophylaxis.
Hemolytic anemia may also occur if administered to individuals with other defects of the erythrocytic pentose phosphate pathway of glucose metabolism or in patients with certain hemoglobinopathies.
The severity of hemolytic anemia depends on dosage and the specific genetic defect in the individual with G-6-PD deficiency. In American and African Blacks with G-6-PD deficiency, hemolysis may be mild, self-limiting, and asymptomatic; in individuals of Mediterranean or certain Asian extractions, hemolysis may be severe.
There is some evidence that a once-weekly (rather than daily) primaquine regimen may result in a lower incidence of hemolytic anemia in American Blacks who are sensitive to primaquine.
Monitor closely if used in individuals who have had a previous idiosyncratic reaction to primaquine (as manifested by hemolytic anemia, methemoglobinemia, or leukopenia), individuals with a personal or family history of favism, or individuals with G-6-PD deficiency or NADH methemoglobin reductase deficiency.
Monitor CBCs periodically during therapy. Do not exceed recommended dosage.
Discontinue immediately if evidence of hemolytic anemia occurs (e.g., darkening of urine, marked fall in hemoglobin level or erythrocyte count).
Specific Populations
Pregnancy
Category C.
CDC and other experts state that use for malaria prophylaxis is contraindicated in pregnant women.
If a pregnant women requires treatment of Plasmodium vivax or P. ovalemalaria, CDC recommends use of oral chloroquine (300 mg once weekly) for prophylaxis for the duration of the pregnancy and deferral of primaquine (to provide a radical cure) until after delivery and after the women has been tested and determined not to have G-6-PD deficiency.
Lactation
CDC states contraindicated during lactation, unless the breast-fed infant has been determined not to have G-6-PD deficiency.
Geriatric Use
Insufficient experience in patients ≥65 years of age to determine whether geriatric patients respond differently than younger adults.
Select dosage with caution (starting at the low end of dosage range) because of age-related decreases in hepatic, renal, and/or cardiac function and potential for concomitant disease and drug therapy.
Well absorbed from GI tract. Peak plasma concentrations generally are attained within 6 hours; plasma concentrations may be negligible after 24 hours.
Considerable interindividual variation in peak plasma concentrations reported.
Distribution
Extent
Widely distributed following oral administration.
Elimination
Metabolism
Extensively and rapidly metabolized in the liver. The principal metabolite is carboxyprimaquine; plasma concentrations of the metabolite greatly exceed those of unchanged primaquine.
Elimination Route
Only small amounts excreted unchanged in urine.
Half-life
3.7–9.6 hours in healthy adults.
Stability
Storage
Oral
Tablets
25°C (may be exposed to 15–30°C) in tight container.
Actions
Tissue schizonticidal agent active against the preerythrocytic and exoerythrocytic forms of Plasmodium falciparum, P. malariae, P. ovale, and P. vivax. Also gametocytocidal against Plasmodium, especially the gametocytes of P. falciparum.
Has some activity against the asexual erythrocytic forms of P. vivax, but generally inactive against the erythrocytic forms of Plasmodium.
Mechanism of antimalarial activity appears to involve interference with Plasmodium DNA.
Advice to Patients
Necessity of taking protective measures to reduce contact with mosquitoes (protective clothing, insect repellents, mosquito nets, remaining in air-conditioned or well-screened areas).
Possibility of contracting malaria during travel, regardless of prophylactic regimen used.
Importance of seeking medical attention as soon as possible if febrile illness develops during or after return from a malaria-endemic area and of informing clinician of possible malaria exposure.
Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, and any concomitant illnesses.
Importance of women informing clinician if they are or plan to become pregnant or plan to breast-feed.
Importance of advising patients of other important precautionary information. (See Cautions.)
Preparations
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Comparative Pricing
This pricing information is subject to change at the sole discretion of DS Pharmacy. This pricing information was updated 09/2009. For the most current and up-to-date pricing information, please visit www.drugstore.com. Actual costs to patients will vary depending on the use of specific retail or mail-order locations and health insurance copays.
† Use is not currently included in the labeling approved by the US Food and Drug Administration.
Remember, keep this and all other medicines out of the reach of children,
never share your medicines with others, and use this medication only for the indication prescribed.
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