Pyrimethamine Pharmacology

Pyrimethamine

About Pyrimethamine
Folic acid antagonist, Pyrimidine derivative, Antiprotozoal, Antimalarial.
Mechanism of Action of Pyrimethamine
Pyrimethamine binds to dihydrofolate reductase enzyme and inhibits the reduction of Dihydrofolic acid (DHFA) to Tetra hydrofolic acid (THFA) .This will interfere the synthesis of folic acid in malarial parasite.
Pharmacokinets of Pyrimethamine
Absorption: It is well absorbed after oral administration.Distribution: It is widely distributed in the body in plasma protein bound form.Metabolism: It undergoes metabolism in the liver. Excretion: Excreted mainly through urine and also through breast milk.
Onset of Action for Pyrimethamine
30 - 60 minute
Duration of Action for Pyrimethamine
8 - 10 hours
Half Life of Pyrimethamine
2 - 6 days
Side Effects of Pyrimethamine
1.Nausea
2.Vomiting
3.Anorexia
4.Abdominal cramps
5.Thrombocytopenia
6.Megaloblastic anaemia
7.Glossitis
8.Pruritis
9.Rash


Contra-indications of Pyrimethamine
1.Hypersensitivity to Pyrimethamine
2.Megaloblastic anaemia caused by folic acid deficiency
Special Precautions while taking Pyrimethamine
1. Hepatic dysfunction
2. Renal impairment
3. Epilepsy
4. Patients with G -6-PD deficiency
5. Asthma
Pregnancy Related Information
Contraindicated.
Old Age Related Information
Use with caution
Breast Feeding Related Information
Contraindicated.
Children Related Information
Use with caution
Indications for Pyrimethamine
1. Malaria (treatment and chemoprophylaxis)
2. Toxoplasmosis
3. Isosporiasis
Interactions for Pyrimethamine
Antifolic drugs (e.g: Methotrexate, Sulphonamides TMP-SMZ): Do not use these agents while the patient is receiving sulfadoxine/pyrimethamine.

Typical Dosage for Pyrimethamine
Adult: Malaria: 50 mg once daily for 2 days followed by 25 mg once in 7 days for 2 - 3 months along with a Sulphonamide
Chemoprophylaxis: 25 mg once weekly for 2 - 3 months
Schedule of Pyrimethamine
H
Storage Requirements for Pyrimethamine
The drug should be stored in cool dark place. Protect away from sun light. Keep out of the reach of children
Effects of Missed Dosage of Pyrimethamine
Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.
Effects of Overdose of Pyrimethamine
Give supportive measures and treatment. Gastric lavage has to be done followed by administration of cathartic. To control seizure Barbiturates can be given to the patient.Leucovorin is given to reduce the hematological side effect.

Home Delivery for Pyrimethamine in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including pyrimethamine.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for pyrimethamine and other medicines and health products. Home delivery services for pyrimethamine may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take pyrimethamine only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for pyrimethamine before they complete the sale. You can get this information while placing the order for pyrimethamine with the pharmacy.

Pyrimethamine is a generic medicine name and there are several brands available for it. Some of the brands for pyrimethamine might be better known than pyrimethamine itself. If the pharmacy that's willing to deliver medicines to your home doesn't have pyrimethamine in stock, you can ask for one of the branded alternatives for pyrimethamine.