The list of drugs that may have adverse effects on hearing or balance is impressive (see also Chap. 24). It includes anaesthetics, anticonvulsants, antidepressants, analgesics, antidiabetics, antihypertensive agents, anti-inflammatory drugs, contraceptives, cytotoxic agents, cardiovascular drugs, sedatives, and tranquillizers (Table 28.1; Ballantyne and Ajodhia 1984; Black and Pesznecker 1993; Rascol et al. 1995). Historically, the first identified ototoxic drugs were naturally occurring substances, e.g. mercury as a primary treatment for syphilis, followed by the first aminoglycoside antibiotic effective against tuberculosis (Black and Pesznecker 1993). Irreversible deafness and disturbance of balance were reported in the first clinical trial of streptomycin (Hinshaw and Feldman 1945). An exhaustive treatment of the extensive literature on drugs causing vestibular and oculomotor dysfunction is, however, beyond the scope of this monograph.