TREATMENT OF THE HYPERVENTILATION SYNDROME WITH BISOPROLOL - A PLACEBO-CONTROLLED CLINICAL-TRIAL

The hyperventilation syndrome (HVS) can be regarded as a form of panic disorder associated with a relative increase in sympathomimetic tone, the effects of which can be counterbalanced by beta-adrenoceptor bloc kade. The efficacy of the beta-blocker bisoprolol was investigated in a double-blind placebo-controlled randomised crossover trial involving 60 patients from 17 general practices. Following a single-blind place bo prephase, patients who met the inclusion criteria were randomised t o treatment with either 5 mg bisoprolol or an identical-looking placeb o tablet once daily for three weeks. They were then crossed over to th e other treatment arm. At the end of each treatment phase the number o f hyperventilation attacks and the severity of symptoms were assessed and side effects recorded. The number of attacks decreased from 4.04 p er week at baseline to 3.52 with placebo and to 1.26 with bisoprolol. The decrease of attacks with bisoprolol was significant (p < 0.05) com pared to baseline and placebo. The severity of the complaints improved from 29 (scale 0 to 64) at baseline not significantly to 26 with plac ebo and significantly (p < 0.05) to 15 with bisoprolol. No serious sid e effects were reported. Five milligrams of bisoprolol once daily is e ffective and safe in the maintenance of symptom reduction in patients with the hyperventilation syndrome.