Methadonesold under the brand name Dolophine among others, is an opioid used for opioid maintenance therapyto help with tapering in people with opioid dependenceand for pain.
Side effects are similar to those of other opioids. Methadone is used for the treatment of opioid dependency. It may be used as a long-term maintenance therapy or in shorter periods for detoxification without withdrawal symptoms. The treatment of opioid-dependent persons with methadone will follow one of two routes.
It is prescribed once or twice daily for those who wish to abstain from illicit drug use. People are given the medication in a clinic, where afterwards they are observed for around minutes for prevention of diversion of methadone to others.
The duration of methadone treatment ranges from a few months to several years, or even lifelong. Methadone reduction, called detoxification, are suitable for persons who wish to completely stop using drugs. The length of time a person remains in treatment depends on a number of factors.
Que es metadona yahoo dating The starting dose depends on the type and quantity of drugs being used at onset of treatment. It also depends on how long the person has been using the drug s and the method i. Both methadone abuse and lawfully prescribed use will eventually lead to dependence. However, when used correctly in treatment, maintenance therapy has been found to be medically safe, non-sedating, and can provide a slow recovery from opioid addiction.
Methadone is approved in the US, and many other parts of the world, for the treatment of opioid addiction. Its use for the treatment of addiction is usually strictly regulated.
Methadone is used as an analgesic in chronic pain, often in rotation with other opioids. Adverse effects of methadone include: Physical symptoms [ citation needed ].
Cognitive symptoms [ citation needed ]. Methadone withdrawal symptoms are reported as being significantly more protracted than withdrawal from opioids with shorter half-lives.
Methadone is sometimes administered as an oral liquid.
Methadone has been implicated in contributing to significant tooth decay. Methadone causes dry mouthreducing the protective role of saliva in preventing decay.
Other putative mechanisms of methadone-related tooth decay include craving for carbohydrates related to opioids, poor dental care, and general decrease in personal hygiene. These factors, combined with sedation, have been linked to the causation of extensive dental damage.
The respiratory depression of an overdose can be treated with naloxone. Despite methadone's much longer duration of action compared to either heroin and other shorter-acting agonists, and the need for repeat doses of the antagonist naloxone, it is still used for overdose therapy. As naltrexone has a longer half-life, it is more difficult to titrate.
If too large a dose of the opioid antagonist is given to a dependent person, it will result in withdrawal symptoms possibly severe. When using naloxone, the naloxone will be quickly eliminated and the withdrawal will be short lived. Doses of naltrexone take longer to be eliminated from the person's system. A common problem in treating methadone overdoses is that, given the short action of naloxone versus the extremely longer-acting methadonea dosage of naloxone given to a methadone-overdosed person will initially "Que es metadona yahoo dating" to bring the person out of overdose, but once the naloxone wears off, if no further naloxone is administered, the person can go right back into overdose based upon time and dosage of the methadone ingested.
As with other opioid medications, tolerance and dependence usually develop with repeated doses. There is some clinical evidence that tolerance to analgesia is less with methadone compared to other opioids; this may be due to its activity at the NMDA receptor.
Tolerance to the different physiological Que es metadona yahoo dating of methadone varies; tolerance to analgesic properties may or may not develop quickly, but tolerance to euphoria usually develops rapidly, whereas tolerance to constipation, sedation, and respiratory depression develops slowly if ever.
Methadone treatment may impair driving ability. In the study of a group of drug abusers, most of them poly-drug abusers, 17 were involved in crashes killing people, compared with a control group of other people randomly selected having no involvement in fatal crashes. The licence will be issued for 12 months at a time and even then, only following a favourable assessment from their own doctor. In the United States, deaths linked to methadone more than quadrupled in the five-year period between and According to the
Que es metadona yahoo dating. National Center for Health Statistics,  as well as a series in the Charleston Gazette West Virginia medical examiners listed methadone as contributing to 3, deaths in That number was up from in Approximately 82 percent of those deaths were listed as accidental, and Que es metadona yahoo dating deaths involved combinations of methadone with other drugs especially benzodiazepines.
Although deaths from methadone are on the rise, methadone-associated deaths are not being caused primarily by methadone intended for methadone treatment programs, according to a panel of experts convened by the Substance Abuse and Mental Health Services Administrationwhich released a report titled "Methadone-Associated Mortality, Report of a National Assessment".
The consensus report concludes that "although the data remains incomplete, National Assessment meeting participants concurred that methadone tablets or diskettes distributed through channels other than opioid treatment programs most likely are the central factors in methadone-associated mortality. Inthe U. The change deleted previous information about the usual adult dosage. The Charleston Gazette reported, "The old language about the 'usual adult dose' was potentially deadly, according to pain specialists.
The bioavailability and elimination half-life of methadone are subject to substantial interindividual variability.
Its main route of administration is oral. Adverse effects include sedation, hypoventilationconstipation and miosisin 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.
The metabolic half life of methadone differs from its duration of action. The metabolic half life is 8 to 59 hours approximately 24 hours for opioid-tolerant people, and 55 hours in opioid-naive peopleas opposed to a half life of 1 to 5 hours for morphine. Methadone has been shown to reduce neuropathic pain in rat models, primarily through NMDA receptor antagonism. Glutamate is the primary excitatory neurotransmitter in the central nervous system.
NMDA receptors have a very important role in modulating long-term excitation and memory formation. Acting as an NMDA antagonist may be one mechanism by which methadone decreases craving for opioids and tolerance, and has been proposed as a possible mechanism for its Que es metadona yahoo dating efficacy regarding the treatment of neuropathic pain. The dextrorotary form dextromethadonewhich acts as an NMDA receptor antagonist and is devoid of opioid activity, has been shown to "Que es metadona yahoo dating" analgesia in experimental models of chronic pain.
Methadone has a slow metabolism and very high fat solubilitymaking it longer lasting than Que es metadona yahoo dating drugs. Methadone has a typical elimination half-life of 15 to 60 hours with a mean of around However, metabolism rates vary greatly between individuals, up to a factor of  ranging from as few as 4 hours to as many as hours, or even hours. Many substances can also induce, inhibit or compete with these enzymes further affecting sometimes dangerously methadone half-life.
A longer half-life frequently allows for administration only once a day in Opioid detoxification and maintenance programs. People who metabolize methadone rapidly, on the other hand, may require twice daily dosing to obtain sufficient symptom alleviation while avoiding excessive peaks and troughs in their blood concentrations and associated effects.
The analgesic activity is shorter than the pharmacological half-life; dosing for pain control usually requires multiple doses per day normally dividing daily dosage for administration at 8 hour intervals.
The most common route of administration at a methadone clinic is in a racemic oral solution, though in Germany, only the R enantiomer the L optical isomer has traditionally been used, as it is responsible for most of the desired opioid effects. Methadone is available in traditional pill, sublingual tablet, and two different formulations designed for the person to drink.
Drinkable forms include ready-to-dispense liquid sold in the United States as Methadoseand "Diskets" which are tablets designed to disperse themselves rapidly in water for oral administration, used in a similar fashion to Alka-Seltzer.
The liquid form is the most common as it allows for smaller dose changes. Methadone is almost as effective when administered orally as by injection. In fact, injection of methadone does not result in a " rush " as with some other strong opioids such as morphine or hydromorphonebecause its extraordinarily high volume of distribution causes it to diffuse into other tissues in the body, particularly fatty tissue; the peak concentration in the blood is achieved at roughly the same time, whether the drug is injected or ingested.
Methadone pills often contain talc   that, when injected, produces a swarm of tiny solid particles in the blood, causing numerous minor blood clots. These particles cannot be filtered out before injection, and will accumulate in the body over time, especially in the lungs and eyes, producing various complications such as pulmonary hypertensionan irreversible and progressive disease.
Information leaflets included in packs of UK methadone tablets state that the tablets are for oral use only and that use by any other route can cause serious harm. In addition to this warning, additives have now been included into the tablets formulation to make the use of them by the IV route more difficult. Methadone and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine EDDPare often measured in urine as part of a drug abuse testing program, in plasma or serum to confirm a diagnosis of poisoning in hospitalized victims, or in whole blood to assist in a forensic investigation of a traffic or other criminal violation or a case of
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