The Medicines and Healthcare products Regulatory Agency (MHRA) on Monday (18 February) issued a new drug safety update, warning increased risk of congenital malformations and risk of acute pancreatitis associated with Carbimazole drug.
MHRA directs women of childbearing potential to use effective contraception during treatment with carbimazole, which is authorised for hyperthyroidism, as it is associated with an increased risk of congenital malformations, especially when administrated in the first trimester of pregnancy and at high doses.
The malformations reported include aplasia cutis congenital (absence of a portion of skin, often localised on the head), craniofacial malformations (choanal atresia; facial dysmorphism), defects of the abdominal wall and gastrointestinal tract (exomphalos, oesophageal atresia, omphalomesenteric duct anomaly), and ventricular septal defect.
Carbimazole should only be considered in pregnancy only after a thorough individual assessment of benefits and risks of treatment, and only at the lowest effective dose without additional administration of thyroid hormones. Close maternal, foetal, and neonatal monitoring is recommended.
The agency also suggests to immediately discontinue the treatment with carbimazole if the patient develops acute pancreatitis and advises that re-exposure to carbimazole may result in life-threatening acute pancreatitis with a decreased time to onset. Re-exposure to carbimazole must be avoided in patients who have a history of acute pancreatitis with carbimazole or thiamazole.
Healthcare professionals, patients and caregivers can report suspected side effects through the Yellow Card scheme.