Efficacy of gabapentin versus diclofenac in the treatment of chest pain and paresthesia in patients with sternotomy.

OBJECTIVE: Chronic post-sternotomy chest pain and paresthesia (PCPP) are frequently seen and reduce the quality of life. We aimed to demonstrate the efficacy and safety of gabapentin compared with diclofenac in the treatment of PCPP and to elucidate the similarities of PCPP to neuropathic pain syndromes.

METHODS: The prospective, randomized, open-label, blinded end-point design of study was used. One hundred and ten patients having PCPP lasting three months or more were randomized to receive 800 mg/daily gabapentin (n=55) and 75 mg/daily diclofenac (n=55) for thirty days. All patients have undergone cardiac surgery and median sternotomy. The perception of pain or paresthesia was evaluated as 0--Normal (no pain or paresthesia), 1--Mild, 2--Moderate, 3--Severe at baseline and after thirty days of treatment. Recurrences were questioned after three months. Statistical analyses were performed using independent samples t, Chi-square, continuity correction, Fisher's exact, Mann Whitney U and Kruskal Wallis tests.

RESULTS: In gabapentin group, mean pain and paresthesia scores regressed from 2.12+/- 0.76 to 0.54+/- 0.83 (p<0.001) and from 1.72+/- 0.74 to 0.49+/- 0.62 (p<0.001), respectively. Mean pain and paresthesia scores regressed in diclofenac group from 1.93+/- 0.8 to 1.0+/- 1.13 (p<0.001) and from 1.76+/- 0.74 to 1.24+/- 0.96 (p=0.002), respectively. Although, both gabapentin and diclofenac were found to be effective without obvious side effects in the treatment of PCPP (p<0.001), gabapentin was found to be superior to diclofenac (p=0.001 and p<0.001, respectively). Adverse effects were seen in 7% of patients on gabapentin and 4% of patients on diclofenac. Results also showed that symptomatic relief with gabapentin lasts longer than diclofenac (p<0.001).

CONCLUSION: Both gabapentin and diclofenac are effective in the treatment of chronic PCPP, without obvious side effects. However, gabapentin is found to be superior to diclofenac and its effects sustain longer. The results show that there may be some evidence in PCPP as a kind of neuropathic pain.