Carbamazepine is a drug commonly prescribed by medical and dental practitioners for the treatment of trigeminal neuralgia. Although included in the Dental Practitioners' Formulary, general dental practitioners (GDPs) rarely prescribe this medication. Those GDPs who do prescribe carbamazepine may need to liaise with the patient's medical practitioner for haematological monitoring. However, a significant number of patients attending their GDP are taking carbamazepine prescribed by hospital colleagues or general medical practitioners. Thus a knowledge of potential side-effects and adverse reactions is useful for all practitioners.