RESUMO
OBJECTIVE: Rapid delivery of migraine-specific medication to its site(s) of action is thought to be crucial in preventing or minimizing sensitization of central pain pathways and thereby in optimizing pain-free outcomes in patients with migraine. Sumatriptan has been developed as a new tablet formulation to enhance the rate of systemic drug delivery by improving tablet disintegration and drug dispersion relative to those of conventional tablets. These enhanced formulation characteristics may be beneficial during occurrences of the gastric stasis that can accompany migraine. METHODS: This randomized, open-label, 4-way crossover study (n = 32) was conducted to determine whether the new formulation of sumatriptan 50 and 100 mg is bioequivalent to sumatriptan conventional tablets and to compare the pharmacokinetic profiles of the new formulation and the conventional tablet during the early (0-2 h) postdose interval in healthy volunteers. Pharmacokinetics during the early post-dose interval are important in determining a drug's onset of action, an important parameter to patients with migraine. RESULTS: The results confirm that the new formulation of sumatriptan and sumatriptan conventional tablets are bioequivalent as demonstrated by the finding that the 90% confidence intervals for the sumatriptan area under the concentration time curve to infinity and to the last evaluable time point (AUC(0- infinity ) and AUC(0-t), respectively) and maximum plasma concentration (C(max)) fell within the predetermined bounds defining bioequivalence (0.80-1.25) for both doses. Pharmacokinetic parameters measured early (0-2 h) after dosing reveal slightly faster absorption, on average, of the new sumatriptan formulation than sumatriptan conventional tablets although high intersubject variability was observed. For the new sumatriptan formulation, AUC(0-2) (AUC up to 2 h post dose) was, on average, 1% greater (50 mg) and 8% greater (100 mg) and maximal sumatriptan levels were attained, on average, 10 min earlier (50 mg) and 15 min earlier (100 mg) compared with the conventional tablet. Other measures including AUC(0-0.5) (AUC to 30 min post-dose), times to achieve sumatriptan concentrations of 5 and 10 ng/mL, and mean percentage C(max) 15, 20 and 30 min post-dose demonstrate an observable improvement in rate of drug absorption for the new form of sumatriptan compared with conventional tablets. CONCLUSION: The new form of sumatriptan is bioequivalent to sumatriptan conventional tablets and is absorbed more quickly than conventional tablets.
