A new study recently published in the journal Annals of the Rheumatic Diseases revealed that the drug sildenafil can help on the healing of digital ulcers in patients with systemic sclerosis. The study is entitled “Efficacy of sildenafil on ischaemic digital ulcer healing in systemic sclerosis: the placebo-controlled SEDUCE study” and was conducted by a team of researchers at several hospitals and universities in France.

Systemic sclerosis, also known as scleroderma, is a rare, chronic autoimmune disease in which the body’s own immune system attacks healthy tissues, resulting in a hardening and tightening of the skin and connective tissues due to excessive collagen deposition. The disease usually affects the skin, but it can also affect internal organs such as the lungs, heart, blood vessels, kidneys and the digestive tract.

Digital ulcers are a common complication in systemic sclerosis patients that result from microangiopathy, where the walls of small vessels become thick and weak, slowing blood flow. Digital ulcers can be very painful and lead to open sores on fingers and toes, affecting the patient’s ability to perform daily tasks and their quality of life.

Sildenafil, also known as Viagra, is a drug used in the treatment of erectile dysfunction and pulmonary arterial hypertension. The drug acts by inhibiting phosphodiesterase type 5 (PDE5), an enzyme that promotes the degradation of cGMP (cyclic guanosine monophosphate), which is a molecule that regulates blood flow. Sildenafil has vasodilation properties and has been reported to induce an increase in blood flow velocity in digital capillaries.

In the study, researchers conducted a randomized, placebo-controlled trial to assess the effect of sildenafil (20 mg), three times a day for a period of 12 weeks, on digital ulcer treatment in 83 systemic sclerosis patients. In total, the patients had 192 digital ulcers. The trial is registered under the number NCT01295736 (SEDUCE study).

Researchers found that at 8 and 12 weeks after treatment, the mean number of digital ulcers per patient was lower in the group under sildenafil treatment in comparison to the placebo group, suggesting that sildenafil promotes a greater healing rate. However, the team could not conclude that sildenafil treatment actually shortened the time of digital ulcer healing.

The team concluded that sildenafil seems to have a clinical benefit in digital ulcer healing in patients with systemic sclerosis.