beta blockade and intermittent claudication: placebo controlled trial of atenolol and nifedipine and their combination.
OBJECTIVE
To determine the effects of the beta 1 selective adrenoceptor blocker atenolol, the dihydropyridine calcium antagonist nifedipine, and the combination of atenolol plus nifedipine on objective and subjective measures of walking performance and foot temperature in patients with intermittent claudication.


METHODS
Randomised controlled double blind four way crossover trial.


METHODS
Royal Hallamshire Hospital, Sheffield.


METHODS
49 patients (40 men) aged 39-70 with chronic stable intermittent claudication.


METHODS
Atenolol 50 mg twice daily; slow release nifedipine 20 mg twice daily; atenolol 50 mg plus slow release nifedipine 20 mg twice daily; placebo. Each treatment was given for four weeks with no washout interval between treatments.


METHODS
Claudication and walking distances on treadmill; skin temperature of feet as measured by thermistor and probe; blood pressure before and after exercise; subjective assessments of walking difficulty and foot coldness with visual analogue scales.


RESULTS
Atenolol did not significantly alter claudication distance (mean change -6%; 95% confidence interval 1% to -13%), walking distance (-2%; 4% to -8%), or foot temperature. Nifedipine did not alter claudication distance (-4%; 3% to -11%), walking distance (-4%; 3% to -10%), or foot temperature. Atenolol plus nifedipine did not alter claudication distance but significantly reduced walking distance (-9%; -3% to -15% (p less than 0.003)) and skin temperature of the more affected foot (-1.1 degrees C; 0 to -2.2 degrees C (p = 0.05)). These effects on walking distance and foot temperature seemed unrelated to blood pressure changes.


CONCLUSIONS
There was no evidence of adverse or beneficial effects of atenolol or nifedipine, when given singly, on peripheral vascular disease. The combined treatment, however, affected walking ability and foot temperature adversely. This may have been due to beta blockade plus reduced vascular resistance, which might also explain the reported adverse effects of pindolol and labetalol on claudication.
Solomon
S A
SA
University Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield.
Ramsay
L E
LE
Yeo
W W
WW
Parnell
L
L
Morris-Jones
W
W
D000328:Adult; D000368:Aged; D001262:Atenolol / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D015444:Exercise; D005528:Foot; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007383:Intermittent Claudication / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000627:therapeutic use*; D012881:Skin Temperature / Q000187:drug effects; D016138:Walking
D003692:Delayed-Action Preparations; D001262:Atenolol; D009543:Nifedipine