Determination of the optimum dose of subcutaneous salbutamol in asthmatic patients.

Saline and salbutamol (250 mug, 500 mug, 750 mug, and 1000 mug) injections were administered under double-blind conditions to seven chronic stable asthmatic patients. The response on the respiratory system (FEV1, FVC) and cardiovascular system (pulse rate, blood pressure and ECG) was monitored for 3 hours. Increasing the dose of salbutamol increased the peak and weighted average effects of FEV1 and pulse rate. The optimum dose, a titration of desired increases in FEV1 and undesirable increases in pulse rate, is 500 mug but doses up to 1000 mug may be administered if necessary.