levomethadone, or R-(−)-methadone, is the active enantiomer of methadone; having approximately 50x the potency of the S-(+)-enantiomer as well as greater μ-opioid receptor selectivity.

Methadone, sold under the brand names Dolophine among others, is an synthetic opioid that is used as the hydrochloride to treat pain and as maintenance therapy or to help with detoxification in people with opioid dependence. Methadone hydrochloride is a mu-agonist; a synthetic opioid analgesic with multiple actions qualitatively similar to those of morphine. Some data also indicate that methadone acts as an antagonist at the NMDA-receptor. The contribution of NMDA receptor antagonism to methadone’s efficacy is unknown. Most common adverse reactions are: lightheadedness, dizziness, sedation, nausea, vomiting, and sweating. Avoid use mixed agonist/antagonist and partial agonist opioid analgesics with DOLOPHINE because they may reduce analgesic effect of DOLOPHINE or precipitate withdrawal symptoms.

Methadone, sold under the brand names Dolophine among others, is an synthetic opioid that is used as the hydrochloride to treat pain and as maintenance therapy or to help with detoxification in people with opioid dependence. Methadone hydrochloride is a mu-agonist; a synthetic opioid analgesic with multiple actions qualitatively similar to those of morphine. Some data also indicate that methadone acts as an antagonist at the NMDA-receptor. The contribution of NMDA receptor antagonism to methadone’s efficacy is unknown. Most common adverse reactions are: lightheadedness, dizziness, sedation, nausea, vomiting, and sweating. Avoid use mixed agonist/antagonist and partial agonist opioid analgesics with DOLOPHINE because they may reduce analgesic effect of DOLOPHINE or precipitate withdrawal symptoms.

Propoxyphene is a centrally acting opiate analgesic. Propoxyphene is an odorless, freely soluble in water, white crystalline powder with a bitter taste. In vitro studies demonstrated propoxyphene and the metabolite norpropoxyphene inhibit sodium channels (local anesthetic effect) with norpropoxyphene being approximately 2 fold more potent than propoxyphene and propoxyphene approximately 10 fold more potent than lidocaine. Propoxyphene and norpropoxyphene inhibit the voltage-gated potassium current carried by cardiac rapidly activating delayed rectifier (hERG) channels with approximately equal potency. It is unclear if the effects on ion channels occur within therapeutic dose range. Propoxyphene is indicated for the relief of mild to moderate pain.

levomethadone, or R-(−)-methadone, is the active enantiomer of methadone; having approximately 50x the potency of the S-(+)-enantiomer as well as greater μ-opioid receptor selectivity.

levomethadone, or R-(−)-methadone, is the active enantiomer of methadone; having approximately 50x the potency of the S-(+)-enantiomer as well as greater μ-opioid receptor selectivity.