Efficacy of transdermal nitroglycerin combined with etodolac for the treatment of chronic post-thoracotomy pain: An open-label prospective clinical trial

Chronic post-thoracotomy pain (CPP) is associated with surgical intercostal nerve injury. Like other forms of neuropathic pain, there is no ideal treatment. Nitroglycerin (NTG) has been found efficacious in acute pain, but has not been tested for chronic pain with neuropathic characteristics. The present study investigated the efficacy of NTG combined with the nonsteroidal anti-inflammatory drug etodolac for the treatment of CPP. Thirty of 129 patients who underwent thoracotomy within an 18-month period had moderate to severe pain that did not respond to etodolac. NTG, 5 mg/day, was added to the treatment. A significant reduction in VAS was observed on day 14 of treatment (from 66.7±11 to 42.1±5, P<0.05). Similar changes were noted in breakthrough pain intensity and sleep efficiency. The only side effect was mild headache, which was self-limited to the first few days of NTG administration. We conclude that NTG added to etodolac appears to be effective for the treatment of CPP, with minimal side effects. Further randomized blinded studies are required.