Clinical inquiries. Are topical nitrates safe and effective for upper extremity tendinopathies?

Topical nitrates provide shortterm relief with some side effects, especially headache. Topical nitroglycerin (NTG) patches improve subjective pain scores by about 30% and range of motion over 3 days in patients with acute shoulder tendinopathy (strength of recommendation [SOR]: C, small randomized controlled trial [RCT] with no methodologic flaws). NTG patches, when combined with tendon rehabilitation, improve subjective pain ratings by about 30% and shoulder strength by about 10% in patients with chronic shoulder tendinopathy over 3 to 6 months, but not in the long term (SOR: C, RCTs with methodologic flaws). They improve pain and strength 15% to 50% for chronic extensor tendinosis of the elbow over a 6-month period (SOR: C, small RCT with methodologic flaws). NTG patches used without tendon rehabilitation don’t improve pain or strength in chronic lateral epicondylitis over 8 weeks (SOR: C, RCT). Topical NTG patches commonly produce headaches and rashes (SOR: B, multiple RCTs).