Nitroglycerin Patch for Tendinopathy
Nitroglycerin patches are NOT recommended for tendinopathy treatment, as the most recent high-quality evidence shows no clinically meaningful benefit over placebo, despite earlier promising studies.
Evidence Assessment
The evidence for topical nitroglycerin in tendinopathy has evolved significantly, with more recent and rigorous studies contradicting earlier findings:
Most Recent Evidence (2024) - Highest Quality
The 2024 NEAT trial 1 - a well-designed randomized double-blind placebo-controlled study of Achilles tendinopathy - found no significant difference between GTN ointment plus eccentric exercises versus placebo plus eccentric exercises at 6,12, or 24 weeks. The adjusted mean between-group difference in VISA-A scores was -3.8 (95% CI -10.6 to 3.0) at 24 weeks, which is not clinically significant.
Systematic Review Evidence (2022)
A comprehensive meta-analysis 2 examining eight RCTs across multiple tendinopathies (rotator cuff, Achilles, patellar, lateral epicondylitis) concluded that there is no evidence that NTG is more effective than placebo for reducing pain. The effects were "insignificant or borderline significant (probably insignificant clinically)" across all tendinopathy types, regardless of dosage used.
Contradictory Earlier Evidence
Older systematic reviews from 2019 3 and 2011 4 suggested some benefit, particularly for pain with activities of daily living in the short-to-mid term (up to 6 months). However, these reviews included lower-quality studies and have been superseded by more rigorous recent trials.
Clinical Guideline Context
The 2005 American Family Physician guideline 5 on tendinopathy management does not include nitroglycerin in its evidence-based recommendations. Instead, it recommends:
- Relative rest and activity modification
- Eccentric strengthening exercises (Level B evidence)
- NSAIDs for short-term pain relief only
- Corticosteroid injections for acute-phase pain (but no long-term benefit)
- Surgery after 3-6 months of failed conservative therapy
Important Safety Considerations
If nitroglycerin were to be considered despite lack of efficacy evidence, the FDA labeling 6 indicates it is approved only for angina, not tendinopathy. Key safety concerns include:
- Severe hypotension, particularly with upright posture
- Headaches (most common side effect, occurring in significantly more patients than placebo - OR 1.73,95% CI 1.01-2.97) 4
- Contact dermatitis
- Contraindicated with phosphodiesterase inhibitors (sildenafil, tadalafil)
- Caution with volume depletion, low blood pressure, or concurrent antihypertensives
Clinical Bottom Line
Focus treatment on proven interventions: eccentric strengthening exercises combined with activity modification, which have consistent Level B evidence for effectiveness 5. Reserve NSAIDs for short-term pain control only, as they don't alter long-term outcomes. Consider corticosteroid injection for acute severe pain, but counsel patients this provides only temporary relief.
The nitroglycerin story in tendinopathy represents a cautionary tale where early promising results did not hold up under more rigorous scrutiny. The 2024 NEAT trial 1 and 2022 meta-analysis 2 provide the strongest, most recent evidence that should guide current practice.