A randomized, double-blind, placebo-controlled trial on the role of preemptive analgesia with acetaminophen [paracetamol] in reducing headache following electroconvulsive therapy [ECT]

Background: Electroconvulsive therapy (ECT) is a safe and efficient treatment for several severe psychiatric disorders, but its use is limited by side effects. Post-ECT headache is one of the commonest side effects. Preemptive analgesia is effective in post-surgical pain management. The most commonly used analgesic is acetaminophen (paracetamol). However, acetaminophen as a preemptive analgesic for post-ECT headache has not been studied adequately. This study was conducted to compare the incidence and severity of post-ECT headache in patients who were administered acetaminophen pre-ECT with a placebo group. 

Methods: This study was a randomised, double-blind, placebo-controlled trial. Sixty-three patients received 1 g acetaminophen and 63 patients received a placebo identical to acetaminophen. The incidence and severity of headache 2 h before and after ECT were compared between placebo and acetaminophen groups. The severity was measured using a visual analog scale. Generalised linear models were used to evaluate variables associated with post ECT headache. 

Results: Demographic and clinical variables of placebo and acetaminophen groups were comparable except for the energy level used to induce a seizure. Higher proportion of the placebo group (71.4%) experienced post-ECT headache when compared to the acetaminophen group (p < 0.001). The median pain score for headache was 0 (Inter quartile range: 0-2) in acetaminophen group whereas the score was 2 (IQR: 0-4) in placebo group (P < 0.001). Model fitting showed that the administration of acetaminophen is associated with less post-ECT headache (odds ratio = 0.23, 95% CI: 0.11-0.48, P < 0.001).

Conclusion: A significant reduction was seen in both the incidence and severity of post-ECT headache with preemptive analgesia with acetaminophen. Trial registration: Ethical approval was granted by an Ethic review committee, University of Kelaniya, Sri Lanka (P/166/10/2015) and the trial was registered in the Sri Lanka Clinical Trials Registry (SLCTR/2015/27).