Effect of salbutamol and suxamethonium on the plasma potassium concentration.

In a double-blind randomized study, patients received premedication with lorazepam 0.04 mg kg-1 and salbutamol 0.1 mg kg-1 or lorazepam 0.04 mg kg-1 and placebo given orally 2.5-3 h before anaesthesia. The plasma potassium concentration was measured at the time of premedication, before the induction of anaesthesia and at selected intervals after suxamethonium 1 mg kg-1 i.v. The plasma potassium concentration was lower in those patients who received salbutamol than in those given placebo, and remained lower at all the subsequent sample times. Oral salbutamol did not appear to affect the incidence of suxamethonium related muscle pain.