Controlled clinical investigation of dimetophrine versus midodrine in the management of moderately decreased arterial blood pressure

Summary

An open, controlled study was carried out in 30 in-patients with low arterial pressure syndrome to compare the effectiveness and tolerance of dimetophrine and midodrine in restoring blood pressure to normal levels and relieving symptoms. Patients were allocated at random to receive treatment for 15 days with either 100 mg dimetophrine tablets or 2.5 mg midodrine tablets and dosage was adjusted according to each patient's condition. Blood pressure and heart rate were monitored daily, symptoms were assessed every 8 days, and laboratory tests carried out before and after treatment. The results showed that both drugs significantly increased systolic and diastolic pressure to normal levels during the trial period and no patient failed to respond. Dimetophrine showed a significantly faster onset of action in increasing systolic pressure and levels reached a plateau significantly earlier than with midodrine. No significant differences were observed between the effects of the two drugs on diastolic pressure, although there was a smoother and more progressive increase in dimetophrine-treatedpatients. Neither drug significantly modified the heart rate. Both drugs were effective in relieving symptoms but, although there was no significant difference between treatments, patients on dimetophrine experienced somewhat faster and greater relief than those receiving midodrine. At the end of the treatment period, only 11% of dimetophrine-treated patients still complained of mild symptoms compared with 33% of those on midodrine. The mean daily dosage was 3.7 tablets of dimetophrine and 4.9 tablets of midodrine. Both drugs were well tolerated; no side-effects were reported and there were no abnormalities in the laboratory tests.

Key Words::

• Dimetophrine
• midodrine
• hypotension