Ans. is 'a' i.e., Check blood counts o The most common side effect of carbimazole is maculopapular pruritic rash, while most serious adverse effect is agranulocytosis which is reversible.o Patient in the given question presents writh sudden onset fever, rigors and sore throat. Infection of any site which is sudden onset and rapidly progressive in a patient on carbimazole therapy the suspicion should be development of agranulocytosis, so it is essential to do blood counts.