Revatio (sildenafil) has been unexpectedly linked to an increased risk of death when it is prescribed to children — a use that is not approved by the FDA. This finding has prompted the FDA to warn that Revatio should not be prescribed to children suffering from Pulmonary Arterial Hypertension (PAH). The FDA is updating the label, and they are asking Pfizer to conduct additional studies to find out whether the increased risk of death also applies to adults taking Revatio.
UPDATE: FDA Clarifies Warnings on Revatio in Children
March 31, 2014 — The FDA has published a Drug Safety Communication to clarify warnings about using Revatio in children. The FDA is concerned that doctors may not prescribe the medication when it is actually necessary. Revatio can still be prescribed to children if the benefits outweigh the risks — for example, if other treatment options are limited, or if the child is being monitored very closely. Click here to read more.
What is Revatio?
Revatio (sildenafil) is a treatment for Pulmonary Arterial Hypertension (PAH). It works by relaxing the blood vessels in the lungs, which reduces blood pressure. It was invented by Pfizer as an off-shoot of Viagra (which also contains sildenafil, but at much lower doses). The U.S. Food and Drug Administration (FDA) approved Revatio in June 2005 for the treatment of PAH in adults. The FDA has never approved Revatio for use in children, but it is often prescribed “off-label.”
Pulmonary Arterial Hypertension (PAH) is a chronic, incurable disease in which the arteries in the lungs are too narrow, causing chronic high blood pressure (hypertension) in the lungs. Arteries in the lungs can become progressively more damaged. The heart muscle (specifically, the right ventricle) must work harder to force blood into narrow arteries. Over time, the heart muscle gets larger, thickens, loses flexibility, and may ultimately weaken and fail.
Study of Revatio in Children
In 2005, Pfizer conducted the cornerstone clinical trial necessary to gain FDA approval. Researchers found that adults with PAH who were prescribed 20-mg of Revatio three times per day showed a 45-meter improvement in their six-minute walking distance.
In 2012, the journal Circulation published a study conducted by researchers who wanted to know whether Revatio would improve exercise ability in children with PAH. The researchers prescribed Revatio to 234 children between the ages of 1 and 17 years old, who were randomized to receive low, medium, or high dose Revatio, or a placebo.
After 16 weeks, the researchers found that Revatio did not improve the exercise ability of children with PAH. They decided to continue the study, and followed the children for an average of three years. After one year, the researchers began observing deaths. After five years, approximately 20% of the children on high-dose Revatio had died, compared to 5% of children on low-dose Revatio.
Revatio FDA Warnings
August 30, 2012 — The FDA has published a Safety Communication to warn that Revatio should not be prescribed to children with Pulmonary Arterial Hypertension (PAH) due to the increased risk of death and lack of benefit for exercise ability. The FDA made several announcements, including:
- The label on Revatio will be updated to include warnings against using the medication in children (especially chronic use)
- The FDA does not know if adults taking Revatio also have a higher risk of death. They have asked Pfizer to conduct additional safety studies.
- Although Viagra also contains sildinafil, the FDA is not updating the label on Viagra at this time, because the drug is used by different patients, at lower doses, and only intermittently instead of regularly
This is the second Safety Communication the FDA has published for Revatio. The first Safety Communication was published in 2007, and warned about the risk of sudden hearing loss.