Capsules, chews, oral suspension
In dogs and cats, sildenafil is most often prescribed to treat heart and lung problems, including pulmonary hypertension resulting from heart failure, pulmonary abnormalities, and cardiac abnormalities. Sildenafil relaxes the lungs, which allows blood to flow more readily, and decreases stress on the heart.
Possible drug interactions: cimetidine, rifampin, phenobarbital, itraconazole erythromycin, clarithromycin, and ketoconazole. Tell your veterinarian if your pet is on any of these medications.
Flushed or red skin and digestive distress.