MELATONIN AURO

Adverse effects

• Arthralgia
• Infection
• Dizziness
• Dry mouth
• Gastrointestinal discomfort
• Headaches
• Nausea
• Altered mood
• Night sweats
• Skin reactions
• Aggression
• Depression
• Disorientation
• Weight gain
• Electrolyte imbalance

Interactions

• Fluvoxamine: Severe (increases exposure)
• Givosiran: Moderate (increases exposure)
• Phenytoin: Unknown (decreases exposure)
• Axitinib: Unknown (increases exposure)
• Ritonavir: Unknown (decreases exposure)
• Leflunomide: Unknown (decreases exposure)
• Mexiletine: Unknown (increases exposure)
• Osilodrostat: Unknown (increases exposure)
• Rucaparib: Unknown (increases exposure)
• Teriflunomide: Unknown (decreases exposure)

Precautions

• Use with caution in hepatic impairment
• Use with caution in renal impairment
• Drowsiness may persist into the next day, affecting performance of skilled tasks such as driving

Pregnancy

No information available-avoid.

Breast-feeding

Present in milk-avoid.

Storage

Store in a cool, dry place away from light.

Formulations

• Modified-release tablets (Circadin®, Slenyto®)
• Immediate-release tablets (Adaflex®, Ceyesto®, Syncrodin®)
• Hard capsules
• Oral solution

Mechanism of action

Melatonin is a derivative of tryptophan. It binds to melatonin receptor type 1A, which then acts on adenylate cylcase and the inhibition of a cAMP signal transduction pathway. Melatonin not only inhibits adenylate cyclase, but it also activates phosphilpase C. This potentiates the release of arachidonate. By binding to melatonin receptors 1 and 2, the downstream signallling cascades have various effects in the body. The melatonin receptors are G protein-coupled receptors and are expressed in various tissues of the body. There are two subtypes of the receptor in humans, melatonin receptor 1 (MT1) and melatonin receptor 2 (MT2). Melatonin and melatonin receptor agonists, on market or in clinical trials, all bind to and activate both receptor types.The binding of the agonists to the receptors has been investigated for over two decades or since 1986. It is somewhat known, but still not fully understood. When melatonin receptor agonists bind to and activate their receptors it causes numerous physiological processes. MT1 receptors are expressed in many regions of the central nervous system (CNS): suprachiasmatic nucleus of the hypothalamus (SNC), hippocampus, substantia nigra, cerebellum, central dopaminergic pathways, ventral tegmental area and nucleus accumbens. MT1 is also expressed in the retina, ovary, testis, mammary gland, coronary circulation and aorta, gallbladder, liver, kidney, skin and the immune system. MT2 receptors are expressed mainly in the CNS, also in the lung, cardiac, coronary and aortic tissue, myometrium and granulosa cells, immune cells, duodenum and adipocytes. The binding of melatonin to melatonin receptors activates a few signaling pathways. MT1 receptor activation inhibits the adenylyl cyclase and its inhibition causes a rippling effect of non activation; starting with decreasing formation of cyclic adenosine monophosphate (cAMP), and then progressing to less protein kinase A (PKA) activity, which in turn hinders the phosphorilation of cAMP responsive element-binding protein (CREB binding protein) into P-CREB. MT1 receptors also activate phospholipase C (PLC), affect ion channels and regulate ion flux inside the cell. The binding of melatonin to MT2 receptors inhibits adenylyl cyclase which decreases the formation of cAMP.[4] As well it hinders guanylyl cyclase and therefore the forming of cyclic guanosine monophosphate (cGMP). Binding to MT2 receptors probably affects PLC which increases protein kinase C (PKC) activity. Activation of the receptor can lead to ion flux inside the cell. Melatonin is implicated in numerous physiological processes, including circadian rhythms, stress, and reproduction, many of which are mediated by the hypothalamus and pituitary. The physiological actions of melatonin are mainly mediated by melatonin receptors. /The authors/ describe the distribution of the melatonin receptor MT1 in the human hypothalamus and pituitary by immunocytochemistry. MT1 immunoreactivity showed a widespread pattern in the hypothalamus. In addition to the area of the suprachiasmatic nucleus (SCN), a number of novel sites, including the paraventricular nucleus (PVN), periventricular nucleus, supraoptic nucleus (SON), sexually dimorphic nucleus, the diagonal band of Broca, the nucleus basalis of Meynert, infundibular nucleus, ventromedial and dorsomedial nucleus, tuberomamillary nucleus, mamillary body, and paraventricular thalamic nucleus were observed to have neuronal MT1 receptor expression. No staining was observed in the nucleus tuberalis lateralis and bed nucleus of the stria terminalis. The MT1 receptor was colocalized with some vasopressin (AVP) neurons in the SCN, colocalized with some parvocellular and magnocellular AVP and oxytocine (OXT) neurons in the PVN and SON, and colocalized with some parvocellular corticotropin-releasing hormone (CRH) neurons in the PVN. In the pituitary, strong MT1 expression was observed in the pars tuberalis, while a weak staining was found in the posterior and ant

Pharmacodynamics

Melatonin is a hormone normally produced in the pineal gland and released into the blood. The essential amino acid L-tryptophan is a precursor in the synthesis of melatonin. It helps regulate sleep-wake cycles or the circadian rhythm. Production of melatonin is stimulated by darkness and inhibited by light. High levels of melatonin induce sleep and so consumption of the drug can be used to combat insomnia and jet lag. MT1 and MT2 receptors may be a target for the treatment of circadian and non circadian sleep disorders because of their differences in pharmacology and function within the SCN. SCN is responsible for maintaining the 24 hour cycle which regulates many different body functions ranging from sleep to immune functions