Methadone 40mg is an opioid used to treat pain and as maintenance therapy or to help with tapering in people with opioid dependence.Methadone is indicated for the maintenance treatment of opioid dependency
The treatment of opioid-dependent persons with methadone will follow one of two routes,Methadone maintenance therapy (MMT) is prescribed to individuals who wish to abstain from illicit drug use but have failed to maintain abstinence from opioids for significant periods. The duration of methadone maintenance ranges from a few months to lifelong. Methadone reduction programs are suitable for addicted persons who wish to completely stop using drugs,The principal goals of methadone maintenance are to relieve opioid cravings, suppress the abstinence syndrome, and block the euphoric effects associated with opioids.
Methadone 40mg is used as an analgesic in chronic pain. Due to its activity at the NMDA receptor, it may be more effective against neuropathic pain; for the same reason, tolerance to the analgesic effects may be less than that of other opioids.
Side effects are similar to those of other opioids. Commonly these include dizziness, sleepiness, vomiting, and sweating. Serious risks include opioid abuse and a decreased effort to breathe. Abnormal heart rhythms may also occur due to a prolonged QT interval.
Methadone 40 mg acts by binding to the µ-opioid receptor, but also has some affinity for the NMDA ionotropic glutamate receptor. Methadone is metabolized by CYP3A4, CYP2B6, CYP2D6 and is a substrate for the P-Glycoprotein efflux protein in the intestine and brain. The bioavailability and elimination half-life of methadone is subject to substantial inter-individual variability. Its main route of administration is oral. Adverse effects include sedation, hypoventilation, constipation and miosis, in addition to tolerance, dependence and withdrawal difficulties. The withdrawal period can be much more prolonged than with other opioids, spanning anywhere from two weeks to several months. Many factors contribute to its metabolism and excretion rate including the individual’s body weight, history of use/abuse, metabolic dysfunctions, renal system dysfunction, among others.