🍽️ pyrimethamine,(prescription)

Antimalarial Properties: Pyrimethamine is effective against the malaria parasite Plasmodium falciparum, which causes the most severe form of malaria. It works by inhibiting the enzyme dihydrofolate reductase (DHFR) in the parasite, thereby disrupting its ability to synthesize DNA and replicate.

Treatment of Malaria: Pyrimethamine is often used in combination with other antimalarial drugs, such as sulfadoxine or chlorproguanil, to treat uncomplicated malaria infections. It is also used in combination with sulfadoxine as a preventive treatment for malaria in certain regions where drug resistance is not widespread.

Toxoplasmosis Treatment: Pyrimethamine is also used for the treatment of toxoplasmosis, a parasitic infection caused by the protozoan Toxoplasma gondii. It is particularly important in individuals with weakened immune systems, such as those with HIV/AIDS, to prevent severe complications of toxoplasmosis.

Prevention of Congenital Toxoplasmosis: Pyrimethamine may be used in pregnant women to prevent the transmission of toxoplasmosis to the fetus and reduce the risk of congenital toxoplasmosis. It is often used in combination with sulfadiazine and folinic acid in this setting.

Side Effects: Common side effects of pyrimethamine may include gastrointestinal symptoms such as nausea, vomiting, diarrhea, and abdominal pain. It may also cause headache, dizziness, rash, and elevated liver enzymes. These side effects are usually mild and temporary.

Hematologic Effects: Pyrimethamine can suppress the bone marrow's production of blood cells, leading to hematologic side effects such as leukopenia (reduced white blood cell count), thrombocytopenia (reduced platelet count), and megaloblastic anemia (due to folate deficiency).

Folic Acid Supplementation: Pyrimethamine inhibits the action of dihydrofolate reductase, which can lead to folate deficiency. To mitigate this risk, folinic acid (also known as leucovorin) is often prescribed alongside pyrimethamine to prevent or treat folate deficiency and its associated side effects.

Allergic Reactions: Some individuals may experience allergic reactions to pyrimethamine, which can manifest as rash, itching, swelling, or difficulty breathing. Severe allergic reactions such as anaphylaxis are rare but possible.

Drug Interactions: Pyrimethamine may interact with other medications, including antifolate drugs such as methotrexate, increasing the risk of hematologic toxicity. It may also interact with anticonvulsant medications, leading to reduced effectiveness or increased side effects.

Pregnancy and Lactation: Pyrimethamine should be used with caution during pregnancy, especially during the first trimester, as it may pose risks to the developing fetus. It may also be excreted in breast milk, so breastfeeding women should consult their healthcare providers before taking pyrimethamine.