Is nitroglycerin (glyceryl trinitrate) effective for rectal use in treating hemorrhoids?

Nitroglycerin for Hemorrhoids: Efficacy and Practical Considerations

Topical nitroglycerin (glyceryl trinitrate) is effective for treating thrombosed external hemorrhoids and provides pain relief, but its use is significantly limited by headache side effects, making topical nifedipine with lidocaine a superior alternative. 1

Mechanism and Evidence for Efficacy

Nitroglycerin works by relaxing internal anal sphincter hypertonicity, which contributes to pain in hemorrhoidal disease. 1 The medication acts as a nitric oxide donor that mediates sphincter relaxation. 2

Clinical effectiveness:

• Topical nitrates show good results in relieving pain from thrombosed external hemorrhoids 1
• In a small case series, all 5 patients with thrombosed external hemorrhoids reported dramatic pain relief lasting 2-6 hours after application of 0.5% nitroglycerin ointment 2
• Post-hemorrhoidectomy studies demonstrate statistically significant pain reduction on Days 3 and 7 (but not Day 1), with pain scores reduced by -1.51 and -1.66 respectively 3
• GTN ointment significantly improves wound healing at 3 weeks post-hemorrhoidectomy (Odds ratio 3.57, P < 0.0001) 3

Major Limitation: Headache Side Effects

The high incidence of headache is the primary factor limiting nitroglycerin use in clinical practice. 1

• Headaches occur in approximately 35-42% of patients (7 of 19 patients in one study) 2, 4
• Headache side effects were significantly higher in the nitroglycerin group compared to placebo (P < 0.002) 4
• This side effect often leads patients to take additional nonsteroidal anti-inflammatory drugs and acetaminophen (P < 0.0003) 4

Superior Alternative: Nifedipine with Lidocaine

Topical 0.3% nifedipine with 1.5% lidocaine ointment applied every 12 hours for 2 weeks is the preferred topical treatment, achieving 92% resolution rate compared to 45.8% with lidocaine alone. 1

Key advantages over nitroglycerin:

• Works through similar mechanism (relaxing internal anal sphincter) 1
• No systemic side effects, specifically no headaches 1
• Lidocaine provides immediate symptomatic relief of local pain and itching 1
• Superior efficacy data for thrombosed external hemorrhoids 1

Safety Contraindications for Nitroglycerin

If nitroglycerin is used, avoid in patients with: 1

• Hypotension (systolic blood pressure < 90 mm Hg)
• Extreme bradycardia (< 50 bpm) or tachycardia (> 100 bpm)
• Concurrent use of phosphodiesterase-5 inhibitors (sildenafil, tadalafil, vardenafil) due to risk of severe hypotension 1

Practical Application Protocol

For thrombosed external hemorrhoids presenting within 72 hours: Surgical excision under local anesthesia is preferred over any topical treatment, providing faster symptom resolution and lower recurrence rates. 1, 5

For conservative management or later presentation (>72 hours):

• First choice: Topical 0.3% nifedipine with 1.5% lidocaine every 12 hours for 2 weeks 1
• Alternative: Topical nitroglycerin 0.2-0.5% applied 2-3 times daily 2, 4
• Adjunctive: Short-term topical corticosteroids (maximum 7 days only) to reduce inflammation 1, 5
• Supportive: Increased fiber and water intake, stool softeners, oral analgesics 1, 5

Important Clinical Pitfalls

• Never use corticosteroids for more than 7 days due to risk of perianal and anal mucosa thinning 1, 5
• Simple incision and drainage of thrombosed hemorrhoids is NOT recommended due to persistent bleeding and higher recurrence rates 1
• Warn patients about potential headaches if prescribing nitroglycerin, and consider this when choosing between treatment options 1, 4
• Nitroglycerin is not aimed at curing hemorrhoids but rather controlling acute symptoms 6