Comparison of inhaled atropine sulphate and atropine methonitrate

Publisher Website
Google Scholar
Abstract
The bronchodilator potencies of inhaled atropine sulfate and atropine methonitrate were compared alone or in combination with fenoterol in a group of adult asthmatic patients. A cumulative dose response study showed that 2 mg of atropine sulfate produced near maximum bronchodilatation. A larger dose of 4 mg was used in comparing the potency of the drug with 2 mg of atropine methonitrate, a dose previously shown to produce optimum bronchodilatation. In a randomized double-blind fashion atropine methonitrate (2 mg), atropine sulfate (4 mg), fenoterol (400 .mu.g), a combination of atropine methonitrate with fenoterol, a combination of atropine sulfate with fenoterol, and 2 placebos were administered by inhalation on separate days to 8 stable adult asthmatics. Measurements of FEV1 [forced expiratory volume in 1 s] were made before administration of the drugs and at 20 min, 1, 2, 4 and 6 h afterwards. The 2 atropine drugs produced a similar peak effect but the bronchodilatation after atropine methonitrate was more prolonged. In combination the bronchodilatation achieved with both atropine drugs and fenoterol was greater than with either atropine or fenoterol alone, confirming that atropine and an adrenergic drug can have an additive effect. The response with atropine methonitrate and fenoterol showed a significant increase in the FEV1 for 6 h but with atropine sulfate and fenoterol the increase of FEV1 was significantly greater than the placebo for only 4 h. The atropine drugs produce useful bronchodilatation alone or in combination with an adrenergic agent. Of the 2 atropine drugs, the methonitrate appears to be superior to the sulfate as an inhaled bronchodilator in adult asthmatics.