Disposition of naproxen after oral administration during and between migraine attacks

Naproxen is an anti-inflammatory drug widely used in the management of pain and in the treatment of migraine and headache. As gastrointestinal disturbances are a common feature of migraine, the aim of this study was to evaluate the absorption and the efficacy of naproxen administered during migraine attacks. Ten patients were treated with 500 mg of a soluble form of naproxen during and between migraine attacks. Clinical parameters and drug plasma levels were recorded at scheduled times. Pain reduction, from severe to mild was evident by 6.5 +/- 3.4 hours and the total pain score showed a reduction from 2 hours onwards. Pharmacokinetic data showed a slight delay in drug absorption during attacks (absorption half-life and time of maximum drug concentration were increased during attacks), but overall bioavailability of naproxen, as reflected by area under the curve (AUC) and maximum plasma drug concentration were unchanged. Since pain relief was reported, it may be concluded that delayed absorption has little or no influence on the therapeutic effect of naproxen in migraine attacks in fasting patients.