Dose proportionality of moricizine after escalating multiple doses in healthy volunteers

This study was designed to determine the dose linearity and proportionality of moricizine after multiple-dose administrations of 450 to 900 mg/day. The study design was an open-label, four-treatment, four-period sequentials escalating dose. Twelve subjects each received multiple doses of 150, 200, 250, and 300 mg of moricizine every 8 hours during 7 days of treatment. Blood samples for pharmacokinetic determinations were obtained on day 7 of each treatment period during an 8-hour time interval. Cmin determinations were also made on specific days of each treatment period. The AUC tau (area under the curve from time 0 to 8 hours), Cmax, and Cmin parameters were all normalized to the 250-mg (750 mg/day) dose. No statistically significant differences were seen in these parameters at the four treatment levels. It was concluded that moricizine follows first-order or linear pharmacokinetics after multiple dosing and exhibits dose proportional pharmacokinetics in the dosage-range studies. This range corresponds to the clinically useful dosage range.