Electrocardiographic changes during antihypertensive treatment with diltiazem in relation to the achieved serum levels of the drug.
Diltiazem is a calcium channel blocker with antihypertensive and antiarrhythmic actions. In the present study 24 hypertensive patients were treated with diltiazem (180-360 mg daily) for 6 months. The effects on the electrocardiogram (ECG) were studied and were related to the serum levels of diltiazem. Treatment with diltiazem induced a non-significant reduction in heart rate with 3 beats min-1 and decreased blood pressure (-11/-9 mm Hg, p < 0.001). The treatment also induced a prolongation of the PQ-interval (+1.4 cs, p < 0.02), a prolongation only being weakly related to the plasma levels of diltiazem (r = 0.28, not significant) and its metabolite MA (r = 0.37, p = 0.07). Neither was the induced increase in the QT-interval (+0.9 cs, p < 0.05), significantly related to the plasma levels of diltiazem. In conclusion, the plasma levels of diltiazem were not clearly related to the induced changes at the ECG during antihypertensive treatment.
Lind
L
L
Department of Internal Medicine, University Hospital of Uppsala, Sweden.
Lithell
H
H
Johansson
C G
CG
Mörlin
C
C
Ljunghall
S
S
D000328:Adult; D000368:Aged; D004110:Diltiazem / Q000097:blood* / Q000627:therapeutic use*; D004562:Electrocardiography / Q000187:drug effects*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D008297:Male; D008875:Middle Aged
D004110:Diltiazem