What is pyrimethamine?

Pyrimethamine is an antiparasitic compound available in tablet form for oral administration. Each scored tablet contains 25 mg pyrimethamine USP and the inactive ingredients colloidal silicon dioxide, lactose monohydrate, magnesium stearate and pregelatinized starch (corn). Pyrimethamine USP, known chemically as 5-(4- chlorophenyl)-6-ethyl-2, 4-pyrimidinediamine, has the following structural formula: str

What kind of drug is pyrimethamine?

The FDA classifies pyrimethamine as a dihydrofolate reductase inhibitor antimalarial. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.

Can you take pyrimethamine with other medicines?

It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run pyrimethamine against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.

What brand names is pyrimethamine sold under?

We track 2 pyrimethamine-containing products in the U.S.: Pyrimethamine and Daraprim. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.

What forms does pyrimethamine come in?

Across the brands we track, pyrimethamine is currently marketed as tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.

Is there a generic pyrimethamine?

Yes. Our catalog lists 1 generic pyrimethamine product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.

Pyrimethamine: uses, dosing, side effects & brands

Pyrimethamine is a dihydrofolate reductase inhibitor antimalarial sold in the U.S. under 2 brand and generic names, for toxoplasmosis, falciparum malaria and aids-related opportunistic infections. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.

By the pharmaranks editorial teamReviewed against the FDA (openFDA label, NDC Directory & Enforcement) sourcesHow we research

Key facts

Drug class: Dihydrofolate Reductase Inhibitor Antimalarial
Treats: Toxoplasmosis, Falciparum Malaria and Aids-Related Opportunistic Infections
Available as: Tablet
Sold as: 2 products — Pyrimethamine and Daraprim
Prescription?: Prescription only
Generic available?: Yes
Typical price: about $4110 for a 30-count supply

How pyrimethamine is dosed

From the FDA label for Pyrimethamine (application ANDA216983). Other pyrimethamine products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.

For Treatment of Toxoplasmosis: The dosage of pyrimethamine tablets for the treatment of toxoplasmosis must be carefully adjusted so as to provide maximum therapeutic effect and a minimum of side effects. At the dosage required, there is a marked variation in the tolerance to the drug. Young patients may tolerate higher doses than older individuals. Concurrent administration of folinic acid is strongly recommended in all patients. The adult starting dose is 50 to 75 mg of the drug daily, together with 1 to 4 g daily of a sulfonamide of the sulfapyrimidine type, e.g. sulfadoxine. This dosage is ordinarily continued for 1 to 3 weeks, depending on the response of the patient and tolerance to therapy. The dosage may then be reduced to about one half that previously given for each drug and continued for an additional 4 to 5 weeks. The pediatric dosage of pyrimethamine tablets is 1 mg/kg/day divided into 2 equal daily doses; after 2 to 4 days this dose may be reduced to one half and continued for approximately 1 month. The usual pediatric sulfonamide dosage is used in conjunction with pyrimethamine tablets.

Pyrimethamine side effects

Hypersensitivity reactions, occasionally severe (such as Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme, and anaphylaxis), and hyperphenylalaninemia, can occur particularly when pyrimethamine is administered concomitantly with a sulfonamide. Consult the complete prescribing information for the relevant sulfonamide for sulfonamide-associated adverse events. With doses of pyrimethamine used for the treatment of toxoplasmosis, anorexia and vomiting may occur. Vomiting may be minimized by giving the medication with meals; it usually disappears promptly upon reduction of dosage. Doses used in toxoplasmosis may produce megaloblastic anemia, leukopenia, thrombocytopenia, pancytopenia, neutropenia, atrophic glossitis, hematuria, and disorders of cardiac rhythm. Hematologic effects, however, may also occur at low doses in certain individuals (see PRECAUTIONS ; General ). Pulmonary eosinophilia has been reported rarely.

Who shouldn’t take pyrimethamine

Use of pyrimethamine tablets are contraindicated in patients with known hypersensitivity to pyrimethamine or to any component of the formulation. Use of the drug is also contraindicated in patients with documented megaloblastic anemia due to folate deficiency.

Every pyrimethamine product we track (2)

Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.

Pyrimethamine products
#	Drug	Rating	Type	Form	Generic?	Typical price
1	Pyrimethamine	64/100	Prescription	Tablet	Generic	$4110	View →
2	Daraprim	Not yet rated	Prescription	Tablet	Generic	$4110

What pyrimethamine pills look like

Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.

Pyrimethamine pill imprints
Imprint	Strength	Colour	Shape	Maker
L;25	25 mg	white	round	—
L;25	25 mg	white	round	—
DARAPRIM;A3A	25 mg	white	round	—

Frequently asked questions

What is pyrimethamine?: Pyrimethamine is an antiparasitic compound available in tablet form for oral administration. Each scored tablet contains 25 mg pyrimethamine USP and the inactive ingredients colloidal silicon dioxide, lactose monohydrate, magnesium stearate and pregelatinized starch (corn). Pyrimethamine USP, known chemically as 5-(4- chlorophenyl)-6-ethyl-2, 4-pyrimidinediamine, has the following structural formula: str
What kind of drug is pyrimethamine?: The FDA classifies pyrimethamine as a dihydrofolate reductase inhibitor antimalarial. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take pyrimethamine with other medicines?: It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run pyrimethamine against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is pyrimethamine sold under?: We track 2 pyrimethamine-containing products in the U.S.: Pyrimethamine and Daraprim. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does pyrimethamine come in?: Across the brands we track, pyrimethamine is currently marketed as tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic pyrimethamine?: Yes. Our catalog lists 1 generic pyrimethamine product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.

Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.