Both
diltiazem (D) and
nifedipine (N) have been shown to be effective in the treatment of
spastic angina, but they sometimes prove inadequate, even in high doses. These two drugs have been given in combination on the grounds of a possible synergistic action, but the results obtained were limited by side-effects. We decided to administer the combined treatment in half doses to patients with
spastic angina and normal coronary vessels in order to assess its effectiveness and acceptance. The trial was conducted on 13 patients: 11 men and 2 women aged from 37 to 71 years (mean 53 years) with normal or subnormal coronary arteriography. In the absence of any treatment, these patients responded to the
ergonovine test by a coronary
spasm which we were subsequently unable to prevent with either D or N. Each patient underwent, at the same hours, 4
ergonovine tests, the product being injected intravenously every 3 minutes in incremental doses of 1, 2, 3 and 6 micrograms/kg. These tests were performed without treatment, after 3 days of treatments with D alone (360 mg/kg), after 3 days of treatment with N alone (60 mg/kg) and after 3 days of treatment with D (180 mg/kg) plus
N (30 mg/kg). Without treatment,
ergonovine triggered the coronary
spasm in all 13 patients at a mean threshold dose of 2.7 micrograms/kg. Under treatment with D or N given separately, no test became negative, but the threshold doses of
ergonovine rose to 4.5 and 4.6 micrograms/kg respectively (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)