Several drugs can cause agranulocytosis through immunosuppression, of which sore throat is an early indicator. These include: the anti-thyroid drugs carbimazole and propylthiouracil  (there is also a long list of drugs with which these interact to further increase the risk of myelosuppression, see BNF); anti-epileptics such as carbamazepine and valproate; the antibiotics penicillin, chloramphenicol and co-trimoxazole; cytotoxic drugs; NSAIDs (indomethacin, naproxen); allopurinol;  the antidepressants mianserin and mirtazapine, and some anti-psychotics, clozapine in particular.