Aim and background To assess drug-related problems in patients with liver cirrhosis by investigating the prevalence of inadequately dosed drugs and their association with adverse drug reactions (ADRs) and hospitalizations. Methods This was a cross-sectional retrospective study assessing the dose adequacy of drug treatment of 400 cirrhotic patients at hospital admission based on the authors' own previous studies and standard literature. The prevalence of total and preventable ADRs and of hospitalizations due to preventable ADRs was determined. Results Of all 1653 drugs prescribed (median 4 per patient), 336 (20 %) drugs were inadequately dosed in 184 patients. Overall, 210 ADRs (78 % preventable) occurred in 120 patients. Sixty-nine ADRs (33 % of all ADRs) were associated with inadequate drug dosing in 46 patients, of which 68 % were preventable. Nonsteroidal anti-inflammatory drugs and psycholeptics in particular frequently caused preventable ADRs associated with inadequate drug dosing. Inadequate drug dosing was more frequently associated with ADRs than adequate drug dosing, and patients receiving inadequately dosed drugs were more frequently admitted to the hospital due to ADRs. Hospitalization of patients receiving inadequately dosed drugs that caused preventable ADRs resulted in 94 additional hospital days. ConclusionIn this retrospective study, inadequate drug dosing was associated with an increased frequency of ADRs, hospital admissions and hospital days in cirrhotic patients. We therefore conclude that the careful dosing of critical drugs is important in patients with liver cirrhosis.