[The effect of diuretics on the magnitude of the effect of isosorbide dinitrate given as a single dose and after long-term administration. Ergometric study in patients with stable angina pectoris].

The authors assessed in 24 men with stable angina pectoris, using means of ergometry, the antiischaemic and antianginose effects of a combination of the nitrate Iso-Mack retard and the diuretic Moduretic. The effects were compared with the effects of Iso-Mack retard administered alone and with the effects of placebo. The examination was made after a single dose of the drugs and after three-week administration. The authors revealed that a single dose of the diuretic significantly enhanced the effects of nitrate. During long-term administration the diuretic did not prevent a significant diminution of the nitrate effects. Finally the authors discuss possible mechanisms of development of tolerance for nitrates and possibilities how to influence this tolerance by a diuretic.