Melatonin could reduce mortality

A study published by the scientific journal Journal of Medical Virology has shown that oral administration of high doses of melatonin in critically ill patients with COVID-19 it is associated with a better clinical outcome and a significant reduction in mortality.

During the first months of the COVID-19 pandemic, patients admitted to intensive care units (ICUs) They had very high mortality rates and there were few effective therapeutic options.. In this context, the Intensive Medicine Service team at the San Carlos Clinical Hospital in Madrid carried out an open, quasi-experimental (non-randomized) study to evaluate whether melatonin, a hormone known mainly to regulate sleep, could improve the outcome of critically ill patients with severe COVID-19.

“Some previous studies had suggested that it could have beneficial effects against serious infections and intense inflammatory processessuch as those seen in severe COVID-19; However, its role in critically ill patients had barely been explored at the beginning of the pandemic,” said Miguel Sánchez, principal investigator of the study and full academician of Intensive Medicine at the Royal National Academy of Medicine of Spain (RANME).

The study included 335 consecutive patients admitted to the ICU due to COVID-19 severe between March 2020 and April 2021. Patients were included in four consecutive study periods alternating standard treatment (control group without melatonin) or standard treatment with high doses (50, 100 or 200 mg daily in one dose) of oral melatonin administered to the 9:00 p.m.

“As we observe an important decrease in mortality at 90 days in cases treated with melatonin and changes were being introduced in the clinical management of COVID-19, such as corticosteroids, antivirals, colchicine, respiratory management, etc.., we decided to stop the administration of melatonin to observe if the improvement was not attributable to melatonin, but to these modifications. The following 93 ‘control’ cases without melatonin They had a mortality of 34%so we decided to add a fourth phase of 40 patients who did receive a daily dose of 100 mg, in which we once again observed a significant reduction in mortality,” Sánchez explained.

Thus, mortality at 90 days was significantly lower in the two groups treated with melatonin, 20.8 percent compared to 36.1 percent in the groups without melatonin. “This significant effect was maintained even after taking into account the variations in the ICU care load and other relevant clinical factors that can also influence mortality. In addition, patients who received melatonin showed a better evolution of organ failure from the first days of admission,” maintains this academic.

Melatonin treatment was also associated with fewer serious complications. “Fewer nosocomial infections were observed, especially pneumonia associated with mechanical ventilation, less need for intubation, a lower incidence of pulmonary barotrauma and an overall reduction in serious adverse events. Likewise, patients treated with melatonin passed fewer days on respiratory support and had shorter stays in both the ICU and the hospital“, acknowledges this specialist in intensive medicine.

Melatonin could serve as a treatment against future pandemics

The researcher has highlighted that these results open the door to the possibility of investigating melatonin not only in COVID-19, but also in future pandemics and other serious diseases characterized by systemic inflammation and oxidative stress.

“Our intention is to carry out a trial, this time double-blind, randomized, compared with placebo and multicenterin pathologies with similar pathophysiology, such as septic shock (serious infection), resuscitated cardiac arrestbecause free radicals are released when circulation resumes, and ischemic and hemorrhagic strokedue to the neuroprotective effect of melatonin”, concluded Sánchez.