Lack of pharmacokinetic interaction between butorphanol tartrate nasal spray and sumatriptan succinate

The pharmacokinetics of butorphanol tartrate given in a nasal spray with and without the co-administration of sumatriptan succinate were studied in 24 healthy men and women. In this crossover design study, all subjects received 2 treatments: a single 1-mg dose of butorphanol nasal spray and a 1-mg dose of butorphanol nasal spray plus a single 6-mg subcutaneous (SC) dose of sumatriptan. There was a two-week washout period between sessions. Serial blood samples were collected and plasma samples analyzed using validated radioimmunoassay and high-performance liquid chromatography/electrochemical procedures to determine the concentrations of unchanged butorphanol and sumatriptan, respectively. There were no statistically significant differences for butorphanol between the 2 treatments on any of the following pharmacokinetic parameters: Cmax, tmax, AUC, t1/2, CL/f, and Vz/f. Similarly, the pharmacokinetic parameters obtained for sumatriptan (given with butorphanol nasal spray) were comparable with the literature values obtained for a single 6-mg SC dose of sumatriptan. These data show a lack of pharmacokinetic interaction between butorphanol nasal spray and sumatriptan. Butorphanol nasal spray and sumatriptan were well tolerated. The adverse experience profiles of butorphanol nasal spray were comparable between the treatments, with and without sumatriptan. It can be concluded that regimens of butorphanol nasal spray and sumatriptan need not be changed for either pharmacokinetic or safety considerations when the two compounds are co-administered in treating acute migraine attacks.