ODMA (drug)

Metabolite of tramadol

{{Drugbox | verifiedfields = changed | verifiedrevid = 477318679 | IUPAC_name = 4-[[2-(dimethylamino)methyl]-1-hydroxycyclohexyl]phenol | image = ODMA.svg | image_size = 200px | image_alt = Structural formula of O-Desmethyltramadol }}

O-Desmethyltramadol (ODMT) is an active metabolite of the opioid analgesic tramadol. It is primarily responsible for the opioid effects of tramadol, as it has a higher affinity for the mu-opioid receptor compared to the parent compound.

Pharmacology

ODMT is formed in the liver through the O-demethylation of tramadol, a process primarily mediated by the cytochrome P450 enzyme CYP2D6. This metabolic pathway is crucial for the analgesic efficacy of tramadol, as ODMT is significantly more potent in activating the mu-opioid receptor.

Mechanism of Action

ODMT acts as an agonist at the mu-opioid receptor, which is a G protein-coupled receptor involved in pain modulation. By binding to this receptor, ODMT inhibits the release of neurotransmitters such as substance P and glutamate, which are involved in the transmission of pain signals in the central nervous system.

Pharmacokinetics

The formation of ODMT from tramadol is subject to genetic variability due to polymorphisms in the CYP2D6 enzyme. Individuals with different CYP2D6 genotypes may metabolize tramadol at different rates, leading to variations in the levels of ODMT and, consequently, the analgesic effect.

Clinical Significance

The presence of ODMT is a key factor in the clinical use of tramadol as an analgesic. Patients who are poor metabolizers of CYP2D6 may experience reduced analgesic effects, while ultra-rapid metabolizers may be at risk of opioid-related side effects due to higher levels of ODMT.

Safety and Side Effects

As an active metabolite of tramadol, ODMT contributes to both the therapeutic and adverse effects of the drug. Common side effects associated with ODMT include nausea, dizziness, and constipation. In cases of overdose, ODMT can lead to respiratory depression, a serious condition that requires immediate medical attention.

Related pages

• Tramadol
• Opioid
• Cytochrome P450
• Mu-opioid receptor