- Serious side effects such as agranulocytosis may occur in patients receiving methimazole. Patients should be instructed to report signs and symptoms of agranulocytosis, such as fever or sore throat
- Leukopenia, thrombocytopenia, and aplastic anemia (pancytopenia) have also been reported with methimazole. Discontinue therapy in the presence of agranulocytosis, aplastic anemia (pancytopenia), hepatitis, or exfoliative dermatitis and monitor bone marrow function
- Severe hepatic reactions and rare cases of fulminant hepatitis, hepatic necrosis, encephalopathy, and death may occur with use of methimazole
- Examine liver function tests if symptoms of hepatic dysfunction such as anorexia, pruritus, or right upper quadrant pain occur
- Discontinue therapy in the event of clinically significant evidence of liver abnormality, including hepatic transaminase values exceeding 3 times the upper limit of normal
- Therapy can cause fetal harm in pregnant women as it crosses the placental membranes and can induce goiter and cretinism in the developing fetus
- Rare cases of congenital defects have occurred in infants born to mothers who received methimazole during pregnancy
- Advise patient about the potential hazard to the fetus when therapy is used during pregnancy or if the patient becomes pregnant while taking this drug
- Postpartum patients receiving therapy should avoid nursing
- Advise patient to report any evidence of illness, particularly sore throat, skin eruptions, fever, headache, or general malaise while on therapy
- Therapy may cause hypoprothrombinemia and bleeding; monitor prothrombin time during therapy, especially before surgical procedures
Cautions: Use cautiously in:
- Hepatic impairment
- Pregnancy
- Other agents that may cause agranulocytosis
Pregnancy Category:D
Breastfeeding: Maternal doses up to 20 mg/day do not affect thyroid function/intellectual development in breastfed infants. Rare idiosyncratic reactions (e.g; agranulocytosis) might occur with doses > 20 mg/day. Monitor infant's complete blood count with differential count if there is a suspicion of a drug-induced blood dyscrasia. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT)This drug is compatible and considered safe with breastfeeding based upon data from AAP Policy Guidelines (available at http://aappolicy.aappublications.org/cgi/content/full/pediatrics;108/3/776 last accessed 31 March 2011). According to manufacturer's data, use during breastfeeding is contraindicated.
Pricing data from www.DrugStore.com in U.S.A.
- Tapazole 10 MG TABS [Bottle] (KING PHARMA)
100 mg = $146
200 mg = $282.96 - Methimazole 5 MG TABS [Bottle] (SANDOZ)
90 mg = $31
100 mg = $34 - Tapazole 5 MG TABS [Bottle] (KING PHARMA)
100 mg = $91.99
300 mg = $264.96 - Methimazole 10 MG TABS [Bottle] (PAR)
100 mg = $63.99
200 mg = $119.98
Warning: This pricing information is subject to change at the sole discretion of DS Pharmacy. For the most current and up-to-date pricing information, please visit drugstore.com.
