Exacerbation of asthma after pyridostigmine during Operation Desert Storm

Pyridostigmine was first used extensively during Operation Desert Storm for prophylaxis against the effects of nerve agents. After initial reports of asthma exacerbations following its use, we gave 10 asthmatic and 6 non-asthmatic soldiers a 30-mg dose of pyridostigmine. We found no changes in forced vital capacity in any of the soldiers, but observed exacerbation of asthma symptoms in seven of the asthmatics. Severity of the exacerbation correlated best with severity of asthma in the desert and inversely with body weight. The irritant effect of the dust may predispose asthmatics to worsen after pyridostigmine, an effect not seen in the laboratory.