PHRM 211 Lecture Notes - Lecture 13: Μ-Opioid Receptor, Opioid Antagonist, Tramadol
Document Summary
Stimulates serotonin release and inhibits reuptake of serotonin and ne. Cyp2d6 active metabolite (6x more potent than tramadol) Many people have a deficiency in this metabolic pathway reduced effectiveness. Risk of serotonin syndrome when combined with other serotonergic drugs. Weak opioid main issue is serotonergic load. Potential for efficacy in neuropathic pain due to its unique pharmacological profile. Less effect on hypogonadism, as demonstrated in maintenance therapy. Worsening pain despite increasing doses of opioids. Pain that becomes more diffuse, extending beyond distribution of pre-existing pain. Can occur at any dose of opioid, but more commonly with high parenteral doses of morphine or hydromorphone and/or in the setting of renal failure. Pain elicited from ordinarily non-painful stimuli stroking skin with cotton (allodynia) Presence of other opioid hyperexcitability effects: myoclonus, delirium or seizures. Toxic effect of opioid metabolites (e. g. m3g or h3g) Central sensitization as a result of opioid-related activation of nmda receptors in the central nervous system.
