circadian
3 interactions related to circadian
propranolol + melatonin
Propranolol blocks pineal beta-1 adrenergic receptors that control endogenous melatonin synthesis, suppressing nighttime melatonin levels by roughly 50% and contributing to insomnia, vivid dreams, and reduced sleep efficiency. Low-dose oral melatonin at bedtime can restore sleep architecture without compromising propranolol's antihypertensive effect.
metoprolol + melatonin
Metoprolol blocks the beta-1 adrenergic receptors that drive pineal melatonin synthesis, suppressing endogenous nighttime melatonin and contributing to insomnia, vivid dreams, and reduced sleep efficiency. Low-dose oral melatonin can restore sleep without interfering with metoprolol's cardiovascular benefits.
melatonin + magnesium
Melatonin signals the brain that it is biological night through MT1 and MT2 receptors in the suprachiasmatic nucleus, while magnesium acts as a NMDA antagonist and GABA-A agonist, helping the nervous system actually relax around that signal. A double-blind RCT in nursing home residents with primary insomnia (Rondanelli 2011) found that nightly melatonin 5 mg + magnesium 225 mg + zinc 11.25 mg significantly improved sleep quality, ease of falling asleep, and morning alertness versus placebo.