How long does methadone last?

How long does it take before methadone wears off? Generally, after a single oral dose effects can last from 6 to 8 hours, depending on patterns of use. More on duration of methadone effects here.

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How is methadone metabolized? Here, we review methadone effects on the body and brain, including the duration of action and routes of excretion. Then, you will have the chance to ask your questions about methadone or methadone’s addictiveness at the bottom of the page in the comments section. We try to respond to all legitimate questions or anyone needing help with methadone addiction with a personal and prompt response.

Methadone effects on the body and brain

Methadone is a prescription drug used to treat opiate addiction and dependence and/or for the relief of moderate to severe pain. Effects are mediated by opioid receptors in the central nervous system as methadone affects neurotransmission. But in addition to its medicinal use, methadone is very common a drug of abuse, abused for its sedative and euphoric effects. People who abuse methadone are likely to develop tolerance, become physically dependent, or psychologically dependent on methadone (How to treat addiction to methadone?).

Methadone duration of action

Onset of initial effects and the total duration of action of methadone depend on the route of drug administration. In fact, there are several ways that you can take methadone. Methadone can be orally ingested in tablet or liquid form or can be injected via intramuscular or subcutaneous injection.

After parenteral administration, onset takes place within 10 to 20 minutes. After oral administration onset emerges from half to 1 hour. When taken orally, onset is delayed, peak methadone concentrations are lower, but the duration of action lasts longer. After a single oral dose effects can last from 6 to 48 hours, depending whether the user is a chronic methadone user, or not.

Methadone time in the body

Methadone has an elimination half-life of 8 to 59 hours. Unlike other drugs, methadone has a wide bioavailability window varying from 40 to 99%. Up to 90% of methadone binds with blood plasma but after repetitive administration these number drastically change. Why? Because methadone has the potential to accumulate in the body tissue. Undergoing an extensive transformation in the liver to 9 metabolites, methadone is like almost no other drug.

Further, methadone is a synthetic narcotic and belongs under the Schedule ll of DEA controlled substances. As a prescribed medication, methadone is available in the form of tablets of 5-10mg, dispersible tablets 40 mg, oral solutions 1-2 mg/mL strength or injectable solutions of 10 mg/mL. When taken orally, methadone is rapidly absorbed from the gastrointestinal tract and is detectible in the blood within only half an hour.

How long do methadone effects last

The duration of methadone’s analgesic action is usually between 6 to 8 hours. However, oral dose effects can last up to 48 hours, depending on whether or not the user is a chronic methadone user. Furthermore, there is a difference in duration methadone effects between intravenous and intramuscular injection. For example, following intravenous administration 10mg peak plasma methadone concentrations will be reached after 34 minutes. While after intramuscular injection of the same methadone dose will reach peak plasma levels 50 minutes later.

How long does a methadone high last

Methadone highs usually last for around 6-8 hours, but it is important to note that methadone can cause serious sensory and respiratory depression, depending on the dosage and route of administration. Peak respiratory depressant effects of methadone generally occur later and have longer duration than its peak analgesic effect, especially during the early period of dosing. The full analgesic effect of methadone is usually not attained for 3-5 days.

Methadone high effects

Methadone high effects are manifested in both psychological and physiological functioning. Among the most common methadone high effects include drowsiness, dizziness, mood swings and sedation, but methadone is one of the rare drugs that when administered in higher doses can cause depressed reflexes, seriously altered sensory perception and stupor. Coma is the worst case scenario but users need to always have in mind the high level of danger when abusing methadone.

The physiological symptoms of methadone effects include headaches, dry mouth, nausea, constipation, pupils construction and decreased heart rate. You can recognize when somebody is high from methadone by noticing the facial flushing and muscle flaccidity. Most dangerous side effects of taking methadone to get high include heart issues such as decreased heart rate. Furthermore, you may feel changes in your appetite, which will lead to weight changes, especially after prolonged use of methadone. You may also experience problems sleeping and decreased sexual drive.

Methadone duration questions

Do you still have questions about the duration of time methadone affects the body? Please leave your questions below. We do our best to respond to your questions personally and promptly.

Reference Sources: National Highway and Traffic Safety Administration: Methadone
Hazardous Susbstances Data Bank TOXNET: Methadone
U.S. Department of Justice/ National Drug Intelligence Center: Methadone
About the author
Lee Weber is a published author, medical writer, and woman in long-term recovery from addiction. Her latest book, The Definitive Guide to Addiction Interventions is set to reach university bookstores in early 2019.
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