Intranasal medications for the treatment of migraine and cluster headache

Intranasal medications for the treatment of headache have recently received increased attention. This paper reviews intranasal formulations of a variety of available medications (dihydroergotamine mesylate [dihydroergotamine mesilate], sumatriptan, zolmitriptan, butorphanol, capsaicin and lidocaine [lignocaine]) and one experimental medication (civamide, a cis-isomer of capsaicin) for the treatment of migraine and cluster headache. Although the efficacy of intranasal agents varies with the product used, intranasal delivery may be both convenient and more effective than other modes of drug delivery for a variety of reasons: (i) intranasal administration bypasses small bowel gastrointestinal tract absorption, which is often significantly delayed during the acute phase of a migraine attack; (ii) nauseated patients may prefer non-oral formulations as they decrease the chance of vomiting and are more rapidly effective; (iii) intranasal administration causes no pain or injection site reaction and is easier and more convenient to administer than injection or suppository and so may be used earlier in a migraine attack, resulting in better efficacy; (iv) intranasal medication produces the same number or fewer adverse events than injections; and (v) intranasal formulations offer a more rapid onset of action than oral medications, for some of the above reasons and, as such, may be more useful in patients with cluster headache, although this needs to be verified. However, it is important to emphasise that a preference study showed that most patients prefer oral tablets to an intranasal formulation. Also, some nasal preparations have significant adverse effects or are not well absorbed and therefore do not work consistently; others are more challenging to administer as a result of their delivery apparatus. Nevertheless, it is our opinion that nasal preparations increase therapeutic options and may result in faster response times and better efficacy than oral formulations and better patient satisfaction than injectable preparations.