Medically reviewed by Drugs.com. Last updated on Feb 20, 2022.
Physicians should completely familiarize themselves with the complete contents of this leaflet before prescribing primaquine phosphate .
Available Dosage Forms:
Therapeutic Class: Antimalarial
Chemical Class: Aminoquinoline
Uses for primaquine
Primaquine is used to treat malaria and prevents it from coming back after treatment (relapse).
Primaquine belongs to a group of medicines, called antiprotozoals. It works by treating malaria, a red blood cell infection transmitted by the bite of a mosquito. It also prevents the development of the blood forms of the parasite, which are responsible for the relapse.
Primaquine is available only with your doctor's prescription.
Before using primaquine
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For primaquine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to primaquine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
No information is available on the relationship of age to the effects of primaquine in pediatric patients.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of primaquine in the elderly. However, elderly patients are more likely to have age-related liver, kidney, or heart problems, which may require caution and an adjustment in the dose for patients receiving primaquine.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking primaquine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using primaquine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using primaquine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Other medical problems
The presence of other medical problems may affect the use of primaquine. Make sure you tell your doctor if you have any other medical problems, especially:
- Bradycardia (slow heartbeat) or
- Heart disease or
- Heart rhythm problems, or history of or
- Hypokalemia (low potassium in the blood), uncorrected or
- Hypomagnesemia (low magnesium in the blood), uncorrected—Use with caution. May prolong the QT interval.
- Favism, family or personal history of or
- Glucose-6-phosphate dehydrogenase (G6PD) deficiency, mild to moderate or
- Hemolytic anemia, personal or family history of or
- Nicotinamide adenine dinucleotide (NADH) methemoglobin reductase deficiency—May make these conditions worse. May cause hemolytic anemia in patients with these conditions.
- Glucose-6-phosphate dehydrogenase (G6PD) deficiency, severe or
- Lupus or
- Rheumatoid arthritis—Should not be used in patients with these conditions.
Proper use of primaquine
Take primaquine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.
Keep using primaquine for the full treatment time, even if you feel better after the first few doses. Your infection may not clear up if you stop using primaquine too soon.
The dose of primaquine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of primaquine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For malaria:
- Adults— 15 milligrams (mg) once a day for 14 days.
- Children— Use and dose must be determined by your doctor.
- For malaria:
If you miss a dose of primaquine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions while using primaquine
It is very important that your doctor check your progress at regular visits to make sure that primaquine is working properly. Blood tests are needed to check for unwanted effects.
Do not use primaquine together with quinacrine or medicines that can cause bleeding or bone marrow problems.
If your symptoms do not improve within a few days, or if they become worse, check with your doctor.
Using primaquine while you are pregnant can harm your unborn baby. It may also cause birth defects if the father is using it when his sexual partner becomes pregnant. Female patients should use effective birth control during and after treatment with primaquine. Male patients who have female partners should use effective birth control during treatment with primaquine and for at least 3 months after the last dose. If you think you have become pregnant while using primaquine, tell your doctor right away.
Before taking primaquine, you should be tested for G6PD deficiency or favism (blood disorder). Primaquine may cause hemolytic anemia in patients with these conditions. Talk to your doctor if you have concerns about this.
Primaquine may cause heart rhythm problems. Tell your doctor right away if you get dizzy or lightheaded, have fast or irregular heart beats, or feel like fainting.
Malaria is spread by the bites of certain kinds of infected female mosquitoes. If you are living in or will be traveling to an area where there is a chance of getting malaria, the following mosquito-control measures will help to prevent infection:
- If possible, avoid going out between dusk and dawn because it is at these times that mosquitoes most commonly bite.
- Remain in air-conditioned or well-screened rooms to reduce contact with mosquitoes.
- Wear long-sleeved shirts or blouses and long trousers to protect your arms and legs, especially from dusk through dawn when mosquitoes are out.
- Apply insect repellant, preferably one containing DEET, to uncovered areas of the skin from dusk through dawn when mosquitoes are out.
- If possible, sleep in a screened or air-conditioned room or under mosquito netting, preferably coated or soaked with pyrethrum, to avoid being bitten by malaria-carrying mosquitoes.
- Use mosquito coils or sprays to kill mosquitoes in living and sleeping quarters during evening and nighttime hours.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Primaquine side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Incidence not known
- Back, leg, or stomach pains
- black, tarry stools
- bleeding gums
- bluish-colored lips, fingernails, or palms
- chest pain
- dark urine
- difficulty breathing
- dizziness, faintness, or lightheadedness
- fast, slow, pounding, or irregular heartbeat
- general body swelling
- loss of appetite
- nausea or vomiting
- painful or difficult urination
- pale skin
- rapid heart rate
- sore throat
- sores, ulcers, or white spots on the lips or in the mouth
- swollen glands
- unusual bleeding or bruising
- unusual tiredness or weakness
- yellowing of the eyes or skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- itching, skin rash
- pain or discomfort in the chest, upper stomach, or throat
- stomach cramps
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about primaquine
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- Drug class: antimalarial quinolines
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