The pharmacokinetics of muzolimine administered with and without aluminium hydroxide was investigated in volunteers (randomized non-blind cross-over study). Six healthy male volunteers aged 20 to 28 years with a mean body weight of 68 +/- 8 kg received 40 mg muzolimine after a standardized breakfast without and with 1760 mg aluminium hydroxide (Aludrox) administered 10 min before breakfast. Muzolimine concentrations were determined in plasma and urine between 0.5 and 48 h post dosing. The data were analysed using a two- or three-compartment open model. The pharmacokinetic parameters of muzolimine, e.g. absorption half-life, peak concentration, time to reach peak concentration, AUC and mean time, obtained with both treatment regimens, did not show any significant difference (analysis of variance). As a conclusion, the pharmacokinetics of muzolimine is not altered by the ingestion of aluminium hydroxide, which might be important for patients with advanced renal failure.