Evoked-muscle tension increases with acute administration of pyridostigmine. During train-of-four stimulation, tension in the tibialis muscle was recorded. There was a dose-dependant increase of both the first (T1) and fourth (T4) twitches. The increase in T4 was less than that of T1, resulting in fade of the train-of-four responses. The mean train-of-four ratio was 0.87 ± 0.05 at a cumulative pyridostigmine dose of 0.24 mg/kg and above. * P < 0.05 when T1 or T4 is compared with the respective previous T1 or T4 value. # P < 0.05 when T4 is compared with the respective T1 value.