Nitroglycerin patches help patients with common injuries to tendons, a research review suggests. The study team focused on overuse tendon injuries in the shoulders, wrists, heels and knees. Depending on its severity, the condition may be treated with physical therapy, corticosteroid injections to provide short-term pain relief or surgery to repair or replace damaged tendons.

The current study examined another treatment option, nitroglycerin patches, which can have fewer side effects than injections or surgery, said senior author Neal Millar of the University of Glasgow in Scotland. While topical nitroglycerin has been examined for tendon pain for more than two decades, research to date has offered a mixed picture of how well it works for this purpose, Millar said.

To get a better look at the effectiveness of this option, Millar and colleagues analyzed data combined from 10 smaller clinical trials that randomly assigned some patients with tendon pain to use nitroglycerin patches and others to an alternative treatment or to a placebo patch.

After six months of treatment, transdermal nitroglycerin provided more pain relief than placebo, Millar's team reported online in the British Journal of Sports Medicine. "This matters for patients because all other current pharmacological and injection therapies have failed to produce convincing results to improve patient care," Millar said by email.

Physical therapy

Up to one in five patients can suffer headaches from the treatment, and some also experienced stinging where the patches were placed, the analysis found. Based on these results, it may make sense for patients to consider using patches in conjunction with physical therapy in initial efforts to relieve tendon pain, Millar said.

Over 12 to 24 months, however, the patches didn't appear to affect pain when people were at rest. Longer-term use was still associated with better strength and range of motion in some instances.

Patients might also get nitroglycerin gels or ointments, which were not examined in the current study focused on patches. Even so, the results suggest that patches may be a viable option for some patients, said Dr. Selene Parekh of the North Carolina Orthopedic Clinic and Duke University in Durham, North Carolina.

"The benefits are better than placebo and seem to help patients restore activities of daily living," Parekh, who wasn't involved in the study, said. Some patients who get headaches from the patches may also be able to continue using them by cutting the dose, noted Dr. George Murrell. "The treatment for this headache is to cut the patch into smaller pieces, i.e. use a smaller dose," Murrell, who wasn't involved in the study, said.