Adcirca Treatment Improves Survival in Dogs with Pulmonary Hypertension, Study Shows

Adcirca (tadalafil) helped to improve survival in dogs with pulmonary hypertension (PH), a new study suggests.

Knowing the underlying conditions associated with PH can lead to improved health outcomes in dogs, the study stated. The findings might also prove to be important in understanding the disease in humans.

The study, titled “Pulmonary hypertension secondary to respiratory disease and/or hypoxia in dogs: Clinical features, diagnostic testing and survival,” was published in The Veterinary Journal.

Respiratory diseases and hypoxia (abnormally low levels of oxygen) can lead to PH in both dogs and humans. However, relatively little is known about how diseases of the lung affect pulmonary blood pressure in canines. And although this information could have important implications for the management of PH in veterinary medicine, it might also help in the understanding and/or treatment of human disease.

“Understanding the diseases that contribute to pulmonary hypertension can lead to more tailored therapy approaches and help identify which medications are likely to be most beneficial,” Carol Reinero, PhD, professor at the College of Veterinary Medicine at the University of Missouri, and the study’s co-author, said in a news release.

The researchers detail the cases of 47 dogs with PH and associated lung diseases, including conditions such as fibrosis (scarring) of the lungs, blockage of the airway, emphysema, and bronchiectasis (where inflammation in the lungs leads to a thickening of lung tissue that interferes with normal lung function).

“As many of these dogs have multiple issues, a thorough evaluation is needed to address the underlying problems causing the pulmonary hypertension,” Reinero said.

Pulmonary blood pressure was estimated by performing an ultrasound of the heart — an echocardiogram.

Results showed that dogs with the highest pulmonary blood pressure (47 mmHg or greater) had significantly shorter survival times than those with lower pulmonary blood pressure.

The researchers also conducted statistical analyses to determine the factors most associated with longer survival times, and found the only factor to be whether or not the dog had been given tadalafil, an oral once-a-day pill.

Tadalafil is the active component of Adcirca, an approved PH therapy. The compound is also marketed under the brand name Cialis to treat erectile dysfunction and benign prostatic hypertrophy.

Similar to people with PH, “increased severity of PH is predictive of non-survival in dogs. Importantly, PDE5 inhibition [with Adcirca] provided a survival benefit,” the researchers said.