Plasma concentration and efficacy of tolvaptan in cirrhotic patients with refractory ascites

To investigate the relationship between the exposure and efficacy of tolvaptan, we measured pharmacokinetics of total drug at 7 days after repeated doses of 3.75 mg/day tolvaptan in 16 patients with hepatic edema. Nine patients (56.3%) were responders, which were defined as those with body weight reduction of >1.5 kg/week. Serum albumin levels were significantly lower in responders than in non-responders (P = 0.031). However, the pharmacokinetics varied greatly among individuals and was not relevant to the clinical response.