Melatonin and Cardiac Safety

General Safety Profile

The Society for Perioperative Assessment and Quality Improvement (SPAQI) recommends continuing melatonin through the perioperative period, as available evidence demonstrates melatonin is safe in this context 1
The American Academy of Sleep Medicine guidelines report no serious adverse reactions have been documented in relation to melatonin use across age groups, including children and adults, with the most frequently reported adverse events being headache (0.74%) and dizziness (0.74%) 2

The American Academy of Sleep Medicine recommends caution in patients taking warfarin due to potential interactions 3
Patients with epilepsy should use melatonin with caution based on case reports 3
Patients on photosensitizing medications should undergo periodic ophthalmological/dermatological monitoring 3
Patients with impaired glucose tolerance should be aware that melatonin has been associated with impaired glucose tolerance in healthy individuals after acute administration 3

The American Academy of Sleep Medicine recommends starting with 3 mg of immediate-release melatonin, with dose titration in 3 mg increments only if needed, up to a maximum of 15 mg, as higher doses can cause receptor desensitization and more frequent adverse effects 2
Lower doses may be safer than higher doses, and choosing United States Pharmacopeial Convention Verified formulations can help minimize the risk of contaminants 1, 2, 3

The American Heart Association, American College of Cardiology, and Heart Failure Society of America do not list melatonin as a contraindication or harmful agent in patients with cardiac disease, and specifically identify harmful medications in heart failure, yet melatonin is not included in these warnings, indicating its potential safety in cardiac patients 4, 5, 6
The American College of Cardiology guidelines address sleep disorders in heart failure patients and imply melatonin's safety by not mentioning it as a harmful agent, suggesting its potential use in patients with cardiac issues 4, 5, 6

The American College of Cardiology guidelines suggest using melatonin with caution in patients taking warfarin due to potential interactions reported to the World Health Organization, highlighting the need for careful consideration in patients with cardiac conditions 4

The Society for Perioperative Assessment and Quality Improvement recommends continuing melatonin through the perioperative period in cardiac surgery patients, demonstrating confidence in its cardiovascular safety, as a prospective trial in 500 cardiac surgery patients showed melatonin reduced postoperative delirium without cardiac complications 7

A prospective trial of 500 cardiac surgery patients receiving prophylactic melatonin showed reduced postoperative delirium (8.4% vs 20.8%, p=0.001) without any reported cardiac complications, according to the American Society of Anesthesiologists 8, 9, 10, 11

The American Academy of Sleep Medicine suggests exercising caution in cardiac patients taking warfarin, as potential interactions have been reported, and recommends monitoring INR more frequently when initiating or discontinuing melatonin in anticoagulated patients 12