Federal health regulators are warning doctors against using Revatio (sildenafil) in children to treat pulmonary arterial hypertension (PAH). According to a Drug Safety Communication from the U.S. Food & Drug Administration (FDA), the warning was prompted by a clinical trial that showed children taking a high dose of Revatio had an unexpectedly higher risk of death than children taking a low dose. However, low doses of Revatio were not shown to be effective in improving exercise ability.
Sildenafil is the same active ingredient found in Viagra. Revatio is approved to treat patients with PAH, and works by relaxing the blood vessels in the lungs to reduce blood pressure. However, it has never been approved to treat the condition in children, though it is used off-label in this way.
PAH is characterized by continuous high blood pressure in the pulmonary artery. In patients with PAH, the pulmonary arteries become narrow or blocked, forcing the heart to work harder to pump blood through the lungs. Patients with PAH generally suffer from symptoms such as trouble breathing, dizziness, or chronic fatigue. As the condition worsens, the symptoms may limit all physical activity.
According to the FDA, most of the deaths seen in the study that prompted its Revatio warning were the result of pulmonary hypertension and heart failure, which are the most common causes of death in children with PAH. As a result of the study’s findings, the following new information is being added to the Revatio drug label:
• A new warning stating the use of Revatio is not recommended in pediatric patients
• Results of the Revatio trial in pediatric patients
According to the FDA, it is not known how long-term use of Revatio in adults with PAH affects the risk of death. The FDA is requiring Pfizer, the manufacturer of Revatio, to evaluate this risk.
At this time, the FDA says does not believe that the same concern applies Viagra, given the differences in patient population and the different recommended dosing regimens.