Effects of clomipramine hydrochloride on heart rate and rhythm in healthy dogs.
OBJECTIVE
To determine the effects of clomipramine hydrochloride on heart rate and rhythm in dogs.


METHODS
17 healthy Beagles.


METHODS
In experiment 1, 8 dogs received placebo or clomipramine (20 mg/kg of body weight, q 24 h, PO) for 7 days in a 2-way crossover design. In experiment 2, 9 dogs were evaluated for 48 hours before and 24 hours after oral administration of clomipramine (4 or 12 mg/kg) in a 2-way crossover design. Electrocardiogram and heart rate were monitored continuously by use of telemetry.


RESULTS
A significant diurnal rhythm in heart rate was detected; minimum values were recorded at night. Administration of 20 mg of clomipramine/kg induced a significant reduction in heart rate, with peak effect achieved approximately 12 hours after dosing. Administration of 4 or 12 mg of clomipramine/kg did not result in significant changes in heart rate. Sinoatrial and second-degree atrioventricular block and ventricular escape beats were observed during periods of slow heart rate in more dogs that received clomipramine (3 to 4 of 8 dogs), compared with dogs that received placebo (1 to 2 of 8 dogs), but this difference was not significant.


CONCLUSIONS
Short-term administration of clomipramine induced benign cardiovascular effects in dogs rather than the potentially dangerous arrhythmias or tachycardia reported following administration of tricyclic antidepressants to humans. Precautions regarding cardiovascular effects may not be needed for the use of clomipramine in healthy dogs.
Pouchelon
J L
JL
Department of Clinical Veterinary Medicine, University of Maisons-Alfort, France.
Martel
E
E
Champeroux
P
P
Richard
S
S
King
J N
JN
D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D001145:Arrhythmias, Cardiac / Q000662:veterinary; D001772:Blood Cell Count / Q000662:veterinary; D001774:Blood Chemical Analysis; D002997:Clomipramine / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D018592:Cross-Over Studies; D004285:Dogs / Q000502:physiology*; D004562:Electrocardiography / Q000662:veterinary; D005260:Female; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects*; D008297:Male; D013686:Telemetry / Q000662:veterinary
D000929:Antidepressive Agents, Tricyclic; D002997:Clomipramine