Primaquine phosphate is 8-[(4-Amino-1-methylbutyl) amino]-6-methoxyquinoline phosphate, a synthetic compound with potent antimalarial activity. Each 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: Carnauba Wax, Hydroxypropyl Methylcellulose, Lactose, Magnesium Stearate, Microcrystalline Cellulose, Polyethylene Glycol 400, Polysorbate 80, Pregelatinized Starch, Red Ferric Oxide , Talc, Titanium Dioxide.

Last updated on RxList: 9/25/2008

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

Primaquine phosphate is 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 should be administered concurrently in order to eradicate the exoerythrocytic parasites in a dosage of 1 tablet (equivalent to 15 mg base) daily for 14 days.

Primaquine phosphate is supplied in tablets of 26.3 mg (= 15 mg base), bottles of 100. (NDC 0024-1596-01)

Store at 25° C (77° F); excursions permitted to 15° - 30° C (59° - 86° F) [see USP Controlled Room Temperature]

Manufactured for Sanofi-Synthelabo Inc. New York, NY 10016 by Bayer Corporation, Myerstown, PA 17067. Revised November 2007. FDA Rev date: 7/28/2008

Last updated on RxList: 9/25/2008

Gastrointestinal: nausea, vomiting, epigastric distress, and abdominal cramps.

Hematologic: leukopenia, hemolytic anemia in glucose-6-phosphate dehydrogenase (G-6-PD) deficient individuals, and methemoglobinemia in nicotinamide adenine dinucleotide (NADH) methemoglobin reductase deficient individuals.

No information provided.

Last updated on RxList: 9/25/2008

Discontinue the use of Primaquine phosphate promptly if signs suggestive of hemolytic anemia occur (darkening of the urine, marked fall of hemoglobin or erythrocytic count).

Hemolytic reactions (moderate to severe) may occur in individuals with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and in individuals with a family or personal history of favism. Areas of high prevalence of G-6-PD 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 glucose-6-phosphate dehydrogenase) while receiving Primaquine and related drugs.

Usage in Pregnancy

Safe usage of this preparation in pregnancy has not been established. Therefore, use of it during pregnancy should be avoided except when in the judgment of the physician the benefit outweighs the possible hazard.

Since anemia, methemoglobinemia, and leukopenia have been observed following administration of large doses of primaquine, the adult dosage of 1 tablet (= 15 mg base) daily for fourteen days should not be exceeded. It is also advisable to make routine blood examinations (particularly blood cell counts and hemoglobin determinations) during therapy.

If primaquine phosphate is prescribed for (1) an individual who has shown a previous idiosyncrasy to primaquine phosphate (as manifested by hemolytic anemia, methemoglobinemia, or leukopenia), (2) an individual with a family or personal history of favism, or (3) an individual with erythrocytic glucose-6-phosphate dehydrogenase (G-6-PD) deficiency or nicotinamide adenine dinucleotide (NADH) methemoglobin reductase deficiency, the person should be observed closely for tolerance. The drug should be discontinued immediately if marked darkening of the urine or sudden decrease in hemoglobin concentration or leukocyte count occurs.

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.

Last updated on RxList: 9/25/2008

Symptoms of overdosage of primaquine phosphate are similar to those seen after overdosage of pamaquine. They include abdominal cramps, vomiting, burning epigastric distress, central nervous system and cardiovascular disturbances, cyanosis, methemoglobinemia, moderate leukocytosis or leukopenia, and anemia. The most striking symptoms are granulocytopenia and acute hemolytic anemia in sensitive persons. Acute hemolysis occurs, but patients recover completely if the dosage is discontinued.

Primaquine phosphate is contraindicated in acutely ill patients suffering from systemic disease manifested by tendency to granulocytopenia, such as rheumatoid arthritis and lupus erythematosus. The drug is also contraindicated in patients receiving concurrently other potentially hemolytic drugs or depressants of myeloid elements of the bone marrow.

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.

Last updated on RxList: 9/25/2008

Primaquine phosphate is an 8-amino-quinoline compound which eliminates tissue (exoerythrocytic) infection. 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.

Clinical Studies

Malariologists agree that malaria produced by Plasmodium vivax is the most difficult form to treat. This is ascribed to the ability of the parasite to develop extremely resistant tissue forms which are not eradicated by ordinary antimalarial compounds.

Thus, persons with acute attacks of vivax malaria, provoked by the release of erythrocytic forms of the parasite, respond readily to therapy, particularly to Chloroquine phosphate. However, prior to the discovery of primaquine phosphate, no antimalarial drug was available that could be relied on to eliminate tissue (exoerythrocytic) infection and to prevent relapses. The various investigations made with primaquine in experimentally induced vivax malaria in human volunteers and in persons with naturally occurring infections have demonstrated that the drug is a valuable adjunct to conventional therapy in this refractory form of the disease.

Last updated on RxList: 9/25/2008

No information provided. Please refer to the WARNINGS and PRECAUTIONS sections.

Last updated on RxList: 9/25/2008

IMPORTANT NOTE: This is a summary and does not contain all possible information about this product. For complete information about this product or your specific health needs, ask your health care professional. Always seek the advice of your health care professional if you have any questions about this product or your medical condition. This information is not intended as individual medical advice and does not substitute for the knowledge and judgment of your health care professional. This information does not contain any assurances that this product is safe, effective, or appropriate for you.

PRIMAQUINE PHOSPHATE - ORAL

(PRIM-uh-kwin FOSS-fate)

COMMON BRAND NAME(S): Primaquine

USES: This medication is used with other medications to prevent the return (relapse) of a certain parasite that causes malaria (Plasmodium vivax). Primaquine phosphate belongs to a class of drugs known as antiparasitics. It works by killing parasites that may still be alive in the liver, therefore preventing the return of the infection.

OTHER USES: This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

This drug may also be used to treat another kind of malaria, Plasmodium ovale. It may also be used with other medications to treat Pneumocystis pneumonia in AIDS patients.

HOW TO USE: Take this medication by mouth with or without food, usually once daily for 14 days. Follow your doctor's directions exactly. If stomach upset occurs, take primaquine with food.

Dosage is based on the kind of infection you have and response to treatment.

This medication works best when the amount of drug in your body is kept at a constant level. Therefore, take this drug and other antiparasitic drugs at evenly spaced intervals exactly as prescribed by your doctor. To help you remember, take it at the same time each day.

Do not take more or less of this drug than prescribed. Do not stop taking it before completing this prescription unless directed to do so by your doctor, even if you feel better. Skipping or changing your dose without approval from your doctor may cause the amount of parasite to increase, make the infection more difficult to treat (resistant), or worsen side effects.

Tell your doctor if your condition persists or worsens after 1-2 days of taking this medication. If your fever returns after you have completed your treatment with this prescription, contact your doctor so that he/she can determine if the malaria has returned.

SIDE EFFECTS: See also Overdose section.

Nausea, vomiting, stomach upset, and abdominal cramps may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: signs of a certain blood problem methemoglobinemia (e.g., bluish skin/lips/nails, headache, shortness of breath, lightheadedness, weakness, confusion, chest pain, sudden pounding heartbeat), signs of a sudden loss of red blood cells hemolytic anemia (e.g., severe tiredness, brown urine, pale lips/nails/skin, fast heartbeat/breathing with usual activities).

Tell your doctor immediately if any of these rare but very serious side effects occur: signs of serious infection (e.g., high fever, severe shills, persistent sore throat).

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching, swelling, severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

Contact your doctor for medical advice about side effects. The following numbers do not provide medical advice, but in the US you may report side effects to the Food and Drug Administration (FDA) at 1-800-FDA-1088. In Canada, you may call Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking primaquine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: rheumatoid arthritis, lupus, low levels of certain blood enzymes (glucose-6-phosphate dehydrogenase-G6PD, NADH methemoglobin reductase).

Before using this medication, tell your doctor or pharmacist your medical history, especially of: family history of favism/G6PD deficiency.

Caution is advised when using this drug in the elderly because they may be more sensitive to its side effects.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is not known whether this drug passes into breast milk. Do not breastfeed if your infant has G6PD deficiency. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.

This drug should not be used with the following medications because very serious interactions may occur: quinacrine, penicillamine, drugs that may cause decreased white blood cells (e.g., trimethoprim, zidovudine, pyrimethamine, azathioprine).

If you are currently using any of these medications listed above, tell your doctor or pharmacist before starting primaquine.

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US National Poison Hotline at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: persistent nausea/vomiting, burning stomach pain, bluish skin/lips/nails, irregular heartbeat.

NOTES: Do not share this medication with others.

Laboratory and/or medical tests (e.g., G6PD blood test, blood cell counts, hemoglobin) should be performed at the start of treatment and periodically to monitor your progress or check for side effects. Consult your doctor for more details.

MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

STORAGE: Store at room temperature at 77 degrees F (25 degrees C) away from light and moisture. Brief storage between 59-86 degrees F (15-30 degrees C) is permitted. Do not store in the bathroom. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

Information last revised July 2008 Copyright(c) 2008 First DataBank, Inc.