The interaction of suxamethonium with propanidid and thiopentone.

An investigation was carried out in adults aged 20-60 years comparing the interaction of propanidid or thiopentone with the muscle relaxant suxamethonium. An attempt was made to correlate the apnoea time with the incidence and severity of muscle pains. No correlation was found between the apnoea times and the incidence of muscle pains. The overall incidence of muscle pains was 19 per cent. The older age-groups of both sexes had a significantly shorter apnoea time with propanidid Than with thiopentone, when the drugs were used in combination with suxamethonium; this was also true of the young females. On the other hand, there was no difference in the young males between propanidid and thiopentone and their interaction with suxamethonium, but young men had a higher incidence of muscle pains than anybody else.