Dolophine ( Methadone )
Methadone is a potent synthetic opioid. It is used mainly to quench medium and severe pain (Dolmed® 5 mg tablets), as well as for opioid substitution therapy (eg Methadone Martindale Pharma® solution 2 mg / ml). Similar to other opioids used for drug intoxication, methadone causes physical and mental dependence.
Worldwide, methadone is still a drug widely used as a strong painkiller. The applicability of methadone for the treatment of heroin dependence was first shown scientifically in 1965. Methadone is the most common drug in Europe for opioid substitution therapy. In Finland, 40% of patients undergoing opioid substitution therapy receive methadone, which is more than 700 patients. In Finland, people who abuse opioids are estimated to be around 4-6 thousand people, and often they use different drugs. About persons who abuse methadone, there are no exact figures.
Mechanism of action
Methadone Dolophine acts mainly through the μ-opioid receptor of the central nervous system. Methadone is also able to prevent the transport of both serotonin and norepinephrine into the cell. Prevention of transport to the cell increases the effectiveness of analgesic action.
Methadone Dolophine, when taken by mouth, absorbs quickly and well, although significant individual deviations occur. The effect of methadone begins within 30-60 minutes. The effect of a single dose, used to alleviate pain, lasts about 4 hours, but there may be significant individual deviations. With continued use, the agent lasts longer due to its accumulation in the tissues; for example, with opioid substitution therapy, methadone is given only once a day. The approximate half-life is about 24 hours. The taste of the drug is bitter.
Influences and harmful influences
In people who are not used to opioids, methadone acts similarly to morphine. Methadone suppresses the function of the central nervous system, causing blurred consciousness and a sense of pleasure, which drug addicts seek. Nausea, vomiting and intestinal obstruction are common harmful effects, like lack of appetite, dry mouth, sweating and fatigue. Also, there may be violations of sexual functions, lowering blood pressure, slowing of the heartbeat and muscle cramps. In addition to clouding consciousness, methadone can cause respiratory depression, which is considered one of the most serious harmful effects. Because of the effect on the serotonin system, the use of methadone increases the risk of so-called. serotonin syndrome.
With prolonged use, the body becomes accustomed to methadone Dolophine, so the consumer must take ever-increasing doses to achieve the desired effect. The body also gets used to most harmful influences, except for some (intestinal obstruction and miosis, narrowing of the pupil of the eye). With prolonged use, methadone no longer causes a sense of pleasure, but, most likely, prevents the emergence of an abstinence syndrome.
Rapid discontinuation of prolonged use of methadone often causes withdrawal symptoms (Table 1). Because of the long half-life of methadone, the withdrawal syndrome is less pronounced than with the use of short-acting opioids, but lasts longer. Symptoms appear with a delay and worsen only 4-6 days after discontinuation of admission. Usually the symptoms last for 10-12 days, but may last longer. Symptoms rarely threaten life.
Yawning, weakness, depression, loose stool, nausea
Sweating, drooling, tearfulness, a bad cold, sneezing
Pain in the muscles, pain in the internal organs, convulsions of the intestine, vomiting
Anxiety, sleep disturbance, depression, trembling, behavior typical of a drug search
Absence, appetite, weight loss, pupil dilating, frequent palpitations, goosebumps
Increased body temperature, blood pressure and respiratory rate, a feeling of chill
Abuse and risk in overdose
With prolonged use, the methadone Dolophine property causes a sense of pleasure to weaken, but with intravenous use this property is preserved to some extent. At an intravenous reception also enough smaller dose. For these reasons, methadone is used as a drug intravenously. Intravenous use makes dependence easier. Methadone, being a potent opioid of long-term action, is considered especially dangerous for intravenous use, but it is also very dangerous when taken through the mouth.
Doses used in opioid substitution therapy are fatal for people who accidentally use opioids and are dangerous to experienced consumers, especially if there are breaks in use. For people who are not used to opioids, the lethal dose is about 50-100 mg. At intravenous reception this dose is less. With methadone replacement therapy, daily doses at the beginning of the course for oral administration are 10-40 mg, and during maintenance therapy 60-120 mg. If several sessions are missed during therapy, subsequent doses should be reduced by 25-50% in order to prepare for a decrease in tolerability. By the end of the course of replacement therapy, the doses decrease gradually, for example, 2.5-5 mg per week.
Since methadone preparations (tablets, solution) are not intended for intravenous use, as a result of using the intravenous method, auxiliary substances enter the body, which can clog the blood vessels and cause various infections. Eye injuries are also possible. There are other medications that treat pain, Like Morphine and OxyContin.
Overdosing can be treated with naloxone by intravenous infusion or by intramuscular injection. Since methadone has a long-term effect, naloxone may need to be given repeatedly until the action of methadone ceases. In the 2000s, deaths caused by methadone in Finland increased many-fold. Often, a history of mixed use of surfactants, especially benzodiazepines and alcohol or other opioids, is indicated.