Clinical Efficacy of Sildenafil in Treatment of Pulmonary Arterial Hypertension in Dogs

• Published in: Journal of veterinary internal medicine 2010-07, Vol.24 (4), p.850-854
• Main Authors: Brown, A.J, Davison, E, Sleeper, M.M
• Format: Article
• Language: English
• Subjects: Animals; Cross-Over Studies; Dogs; Double-Blind Method; Echocardiography; exercise; Female; Heart disease; Hemodynamics; hypertension; Hypertension, Pulmonary - drug therapy; Hypertension, Pulmonary - veterinary; Male; medicine; people; Piperazines - therapeutic use; polycyclic aromatic hydrocarbons; prognosis; Pulmonary disease; Purines - therapeutic use; quality of life; Sildenafil Citrate; Sulfones - therapeutic use; Vasodilator Agents - therapeutic use
• ISSN: 0891-6640; 1939-1676
• DOI: 10.1111/j.1939-1676.2010.0517.x

Background: Pulmonary arterial hypertension (PAH) in dogs carries a poor prognosis. Sildenafil increases exercise capacity and improves hemodynamics in people with PAH. Hypothesis/Objectives: Dogs receiving sildenafil will have lower pulmonary arterial pressure, increased exercise capacity, and better quality of life (QOL) than dogs receiving placebo. Animals: Thirteen dogs with echocardiographic evidence of PAH. Methods: Prospective short-term, randomized, placebo controlled, double-blind, crossover study. Dogs with PAH were randomly allocated to receive sildenafil or placebo for 4 weeks, followed by the alternative treatment for 4 weeks. Results: Dogs receiving sildenafil had a significantly lower estimated pulmonary arterial pressure (median, 56 mmHg; range, 34–83 mmHg) than at baseline (median, 72 mmHg; range, 61–86 mmHg; P= .018), but not significantly lower than those receiving placebo (median, 62 mmHg; range, 49–197 mmHg). Exercise capacity was significantly greater in dogs receiving sildenafil than those receiving placebo (mean activity count per minute: 101 ± 47 versus 74 ± 32; P= .05). QOL scores were significantly higher in dogs receiving sildenafil than dogs receiving placebo. Conclusions and Clinical Importance: Sildenafil decreases systolic pulmonary arterial pressure from baseline in dogs with PAH and is associated with increased exercise capacity and QOL when compared to treatment with placebo.