Methimazole cannot be taken in which condition?

Methimazole cannot be taken in which condition?

• A. Breastfeeding
• B. Pregnancy
• C. Hyperthyroidism
• D. Hypertension

Answer: (A)

Teratogenic risk during early pregnancy is the key idea here. Methimazole crosses the placenta and, if taken in the first trimester, can cause fetal birth defects such as scalp abnormalities and other malformations. Because of this, it is not used when a patient is pregnant, especially in the first trimester. In practice, clinicians often use an alternative antithyroid drug early on and may switch to methimazole later in pregnancy if needed. Breastfeeding is generally not a contraindication, since small amounts can pass into breast milk, and hypertension is unrelated to methimazole’s effects. The main reason it cannot be used is the risk to the developing fetus in early pregnancy.

Teratogenic risk during early pregnancy is the key idea here. Methimazole crosses the placenta and, if taken in the first trimester, can cause fetal birth defects such as scalp abnormalities and other malformations. Because of this, it is not used when a patient is pregnant, especially in the first trimester. In practice, clinicians often use an alternative antithyroid drug early on and may switch to methimazole later in pregnancy if needed. Breastfeeding is generally not a contraindication, since small amounts can pass into breast milk, and hypertension is unrelated to methimazole’s effects. The main reason it cannot be used is the risk to the developing fetus in early pregnancy.