Pyrimethamine 25 mg Tablet, 100-count
🆔 Identity & classification
Where does this data come from?
🏷️ RxNorm drug class
This medicine belongs to the Dihydrofolate Reductase Inhibitor Antimalarial class.
Where does this data come from?
🏭 Manufacturer & labeler
Where does this data come from?
🩺 Clinical
Patient education
Supplement & herbal interactions
Some supplements/herbs that may interact with Pyrimethamine — tap one for details:
Pyrimethamine may be associated with lower levels of 4 nutrients — worth a chat with your pharmacist, not a cause for alarm.
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Ask a licensed pharmacist directly — free, answered by our team.
💊 What it looks like
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🧪 Inactive Ingredients / Excipients
Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.
💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.
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UNII EWQ57Q8I5X
Lactose monohydrate is a natural sugar derived from milk. It serves as a filler and binder in tablets and capsules, helping create the proper size, texture, and consistency of the medicine.
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UNII 70097M6I30
Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
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UNII O8232NY3SJ
A plant-based carbohydrate derived from corn kernels. It acts as a filler to add bulk, a binder to hold ingredients together, and a disintegrant to help the tablet break apart in your stomach for absorption.
3 inactive ingredients listed in the exact product block matched to this NDC.
Where does this data come from?
ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.Inactive ingredient FAQ
Are inactive ingredients the same for every manufacturer?
Why might an inactive ingredient be missing?
Can inactive ingredients matter?
💲 Pricing
A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.
| Price system | Per ea | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | $137.009 | $13,700.90 / 100 tablets |
| Medicaid paysCMS SDUD · 12 mo | $268.37 | $26,837.20 / 100 tablets |
| Medicare drug plans payPart D · Q2 2026 | $284.05 | $28,404.63 / 100 tablets |
Where does this data come from?
🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Pyrimethamine 25 mg 00480-3720-01 | Teva | 100 tablets | $137.009 | AB | Availability likely | — |
| Pyrimethamine 25 mgthis 43598-0672-01 | DR.REDDYS | 100 tablets | $137.009 | AB | Availability likely | — |
| Pyrimethamine 25 mg 59651-0590-01 | Aurobindo | 100 tablets | $137.009 | AB | Availability likely | — |
| Pyrimethamine 25 mg 72603-0262-01 | NorthStar | 30 tablets | $137.009 | AB | Discontinued | — |
| Daraprim 25 mg 69413-0330-10 | Vyera | 100 tablets | — | AB | FDA listed | — |
| Pyrimethamine 25 mg 72647-0330-01 | OAKRUM | 100 tablets | — | AB | FDA listed | — |
| Daraprim 25 mg 83649-0330-01 | TILDE | 100 tablets | — | AB | FDA listed | — |
Where does this data come from?
⏳ Availability & generic status
This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.
Where does this data come from?
🗺️ Medicaid utilization & spend
💊 Medicaid utilization by pack size
📊 Medicare Part D spend CMS · PART D · 2026 (Q1)
📦 Packaging — all sizes for this product
| Package NDC | Description | Per unit | Per pack | Marketing start | Status |
|---|---|---|---|---|---|
| 43598-0672-01 You're viewing this | 100 TABLET in 1 BOTTLE, PLASTIC (43598-672-01) | $137.01 / ea | $13,700.90 | 2020-03-16 | Active |
| 43598-0672-30 | 30 TABLET in 1 BOTTLE, PLASTIC (43598-672-30) | $137.01 / ea | $4,110.27 | 2020-03-16 | Active |
You're viewing the largest of 2 pack sizes for this product.
This pack has the lowest per-ea cost of the 2 priced pack sizes ($137.01 NADAC).
Pack size FAQ
What quantity is in NDC 43598-0672-01?
What is the difference between NDC 43598-0672-01 and NDC 43598-0672-30?
What NDC number is used to bill for this package of Pyrimethamine 25 mg Tablet?
Prices are the latest CMS NADAC pharmacy acquisition cost per NDC; per-pack figures are per-unit × pack quantity, shown only when the pack is denominated in the same measure NADAC prices.
📄 Full prescribing information FDA SPL
🎯 Indications and Usage ▾
INDICATIONS AND USAGE Treatment of Toxoplasmosis: Pyrimethamine is indicated for the treatment of toxoplasmosis when used conjointly with a sulfonamide, since synergism exists with this combination.
⏱️ Dosage and Administration ▾
DOSAGE AND ADMINISTRATION For Treatment of Toxoplasmosis : The dosage of Pyrimethamine 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 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.
⛔ Contraindications ▾
CONTRAINDICATIONS Use of Pyrimethamine is 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.
⚠️ Warnings ▾
WARNINGS The dosage of pyrimethamine required for the treatment of toxoplasmosis has a narrow therapeutic window. If signs of folate deficiency develop (see ADVERSE REACTIONS ), reduce the dosage or discontinue the drug according to the response of the patient. Folinic acid (leucovorin) should be administered in a dosage of 5 to 15 mg daily (orally, IV, or IM) until normal hematopoiesis is restored.
Data in 2 humans indicate that pyrimethamine may be carcinogenic; a 51-year-old female who developed chronic granulocytic leukemia after taking pyrimethamine for 2 years for toxoplasmosis 3 and a 56-year-old patient who developed reticulum cell sarcoma after 14 months of pyrimethamine for toxoplasmosis. 4 Pyrimethamine has been reported to produce a significant increase in the number of lung tumors in mice when given intraperitoneally at doses of 25 mg/kg. 5 Pyrimethamine should be kept out of the reach of infants and children as they are extremely susceptible to adverse effects from an overdose.
Deaths in pediatric patients have been reported after accidental ingestion.
🤒 Adverse Reactions ▾
ADVERSE REACTIONS 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. To report SUSPECTED ADVERSE REACTIONS, contact Cerovene, Inc. at 1-833-304-9569 or FDA at 1-800-FDA-1088 or www.fda.gov/ medwatch.
🔄 Drug Interactions ▾
Drug Interactions: Pyrimethamine may be used with sulfonamides, quinine and other antimalarials, and with other antibiotics. However, the concomitant use of other antifolic drugs or agents associated with myelosuppression including sulfonamides or trimethoprim-sulfamethoxazole combinations, proguanil, zidovudine, or cytostatic agents (e.g., methotrexate), while the patient is receiving pyrimethamine, may increase the risk of bone marrow suppression. If signs of folate deficiency develop, pyrimethamine should be discontinued.
Folinic acid (leucovorin) should be administered until normal hematopoiesis is restored (see WARNINGS ). Mild hepatotoxicity has been reported in some patients when lorazepam and pyrimethamine were administered concomitantly.
🤰 Pregnancy ▾
Pregnancy: Teratogenic Effects: Pregnancy Category C. Pyrimethamine has been shown to be teratogenic in rats when given in oral doses 2.5 times the human dose for treatment of toxoplasmosis. At these doses in rats, there was a significant increase in abnormalities such as cleft palate, brachygnathia, oligodactyly, and microphthalamia.
Pyrimethamine has also been shown to produce terata such as meningocele in hamsters and cleft palate in miniature pigs when given in oral doses 5 times the human dose for treatment of toxoplasmosis. There are no adequate and well-controlled studies in pregnant women. Pyrimethamine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Concurrent administration of folinic acid is strongly recommended when used for the treatment of toxoplasmosis during pregnancy.
🧒 Pediatric Use ▾
Pediatric Use: See DOSAGE AND ADMINISTRATION section.
🧓 Geriatric Use ▾
Geriatric Use: Clinical studies of Pyrimethamine 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.
🆘 Overdosage ▾
OVERDOSAGE Following the ingestion of 300 mg or more of pyrimethamine, gastrointestinal and/or central nervous system signs may be present, including convulsions. The initial symptoms are usually gastrointestinal and may include abdominal pain, nausea, severe and repeated vomiting, possibly including hematemesis. Central nervous system toxicity may be manifest by initial excitability, generalized and prolonged convulsions which may be followed by respiratory depression, circulatory collapse, and death within a few hours.
Neurological symptoms appear rapidly (30 minutes to 2 hours after drug ingestion), suggesting that in gross overdosage pyrimethamine has a direct toxic effect on the central nervous system. The fatal dose is variable, with the smallest reported fatal single dose being 375 mg. There are, however, reports of pediatric patients who have recovered after taking 375 to 625 mg.
There is no specific antidote to acute pyrimethamine poisoning. In the event of overdosage, symptomatic and supportive measures should be employed. Gastric lavage is recommended and is effective if carried out very soon after drug ingestion.
Parenteral diazepam may be used to control convulsions. Folinic acid should be administered within 2 hours of drug ingestion to be most effective in counteracting the effects on the hematopoietic system (see WARNINGS ). Due to the long half-life of pyrimethamine, daily monitoring of peripheral blood counts is recommended for up to several weeks after the overdose until normal hematologic values are restored.
🧬 Clinical Pharmacology ▾
CLINICAL PHARMACOLOGY Pyrimethamine is well absorbed with peak levels occurring between 2 to 6 hours following administration. It is eliminated slowly and has a plasma half-life of approximately 96 hours. Pyrimethamine is 87% bound to human plasma proteins.
Microbiology: Pyrimethamine is a folic acid antagonist and the rationale for its therapeutic action is based on the differential requirement between host and parasite for nucleic acid precursors involved in growth. This activity is highly selective against Toxoplasma gondii . The action of pyrimethamine against Toxoplasma gondii is greatly enhanced when used in conjunction with sulfonamides.
This was demonstrated by Eyles and Coleman 1 in the treatment of experimental toxoplasmosis in the mouse. Jacobs et al 2 demonstrated that combination of the 2 drugs effectively prevented the development of severe uveitis in most rabbits following the inoculation of the anterior chamber of the eye with toxoplasma.
📦 How Supplied / Storage and Handling ▾
HOW SUPPLIED: Pyrimethamine Tablets USP, 25 mg are supplied as: White, round, biconvex, scored tablet, with C/127 on the upper side; and plain on the lower side in bottles of 100 (NDC 43598-672-01) and bottles of 30 (NDC 43598-672-30) Store at 15° to 25°C (59° to 77°F) in a dry place and protect from light.
📦 Storage and Handling ▾
Store at 15° to 25°C (59° to 77°F) in a dry place and protect from light.
📋 Description ▾
DESCRIPTION Pyrimethamine is an antiparasitic compound available in tablet form for oral administration. Each scored tablet contains 25 mg pyrimethamine and the inactive ingredients pregelatinized starch, lactose monohydrate, and magnesium stearate. Pyrimethamine, known chemically as 5-(4-chlorophenyl)-6-ethyl-2,4-pyrimidinediamine, has the following structural formula: C 12 H 13 CIN 4 Mol.
Wt. 248.71 “FDA approved dissolution test specifications differ from USP”. Structural Formula
💬 Information for Patients ▾
Information for Patients: Patients should be warned that at the first appearance of a skin rash they should stop use of Pyrimethamine and seek medical attention immediately. Patients should also be warned that the appearance of sore throat, pallor, purpura, or glossitis may be early indications of serious disorders which require treatment with Pyrimethamine to be stopped and medical treatment to be sought. Women of childbearing potential who are taking Pyrimethamine should be warned against becoming pregnant.
Patients should be warned to keep Pyrimethamine out of the reach of children. Patients should be advised not to exceed recommended doses. Patients should be warned that if anorexia and vomiting occur, they may be minimized by taking the drug with meals.
Concurrent administration of folinic acid is strongly recommended when used for the treatment of toxoplasmosis in all patients.