Medications used to prevent migraine headaches and their potential ocular adverse effects

We present a detailed review of the medications used in the USA, Canada, and the United Kingdom for the prevention of migraine and the potential ocular adverse effects associated with the use of these medications. Those drugs that are administered for the purpose of reducing the frequency or severity of migraine attacks are classified according to whether they act on the cerebral vasculature primarily at serotonin (5-HT2) receptors (e.g., methysergide, cyproheptadine, and pizotyline), beta adrenergic (primarily beta-2) receptors (e.g., propranolol and timolol), via central nervous system (CNS) adrenergic (alpha-2) receptors (e.g., clonidine), or calcium channels (e.g., flunarizine). The roles and mechanisms of action of tricyclic antidepressants (e.g., amitriptyline) and nonsteroidal anti-inflammatory drugs (NSAIDs) in the prophylactic management of migraine are also discussed, along with possible pharmacogenetic differences in the kinetics of action of some of these drugs. The general indications, contraindications, and potential ocular and systemic adverse effects of each class of drugs is reviewed and presented along with the references to original literature on these effects.