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Drugs Affecting the Musculoskeletal System
Published in Radhwan Nidal Al-Zidan, Drugs in Pregnancy, 2020
Risk Summary: It should be used with caution during the 1st and 2nd Trimesters. However, it is better to avoid the use of Levorphanol near term because of the risk of neonatal respiratory depression if used close to delivery.
Narcotic Analgesics And Antagonists
Published in S.J. Mulé, Henry Brill, Chemical and Biological Aspects of Drug Dependence, 2019
Levorphanol retains all of the analgesic activity of racemorphan and has, thus, four times the activity of morphine. It is highly effective orally. LevorphanoPs side effects are very similar to those of morphine except for a decrease in the frequency of various types of spasms. The dependence liability of levorphanol is said to be as great as, and probably greater than that of morphine.38
Chronic Opioid Therapy: The Argument for Opioid Therapy to Treat Persistent Noncancer Pain
Published in Michael E. Schatman, Ethical Issues in Chronic Pain Management, 2016
In another study, 81 adult patients with refractory neuropathic pain refractory were randomly assigned to receive high-strength (0.75mg) or low-strength (0.15mg) levorphanol capsules for eight weeks under double-blind conditions. Levorphanol was patient-titrated to a maximum of 21 capsules of either strength day. Outcome measures studied included the intensity of pain (diary), the degree of pain relief, QOL, psychological and cognitive function, the number of capsules taken daily, and blood levorphanol levels. High-strength levorphanol capsules reduced pain by 36%, compared with a 21% reduction for the low-strength group (p = 0.02). Patients in the high-strength group averaged 11.9 capsules/day (8.9 mg/day), while patients in the low-strength group required 18.3 capsules/day (2.7mg/day). Affective distress and interference with functioning were reduced, and sleep was improved in both groups. The reduction in the intensity of neuropathic pain was significantly greater during treatment with higher doses of opioids than with lower doses (21).
Pharmacokinetics and pharmacodynamics of dextromethorphan: clinical and forensic aspects
Published in Drug Metabolism Reviews, 2020
Ana Rita Silva, Ricardo Jorge Dinis-Oliveira
DXM (3-methoxy-N-methylmorphinan; Figure 1) is the dextrorotatory [d- or (–)] enantiomer of levomethorphan [l- or (+)], which is the methyl ether of DXO (3-hydroxy-N-methylmorphinan) and levorphanol, respectively (Sromek et al. 2014). Although former levorotatory compounds are both opioid analgesics, only levorphanol was clinically developed (Gudin et al. 2016; Le Rouzic et al. 2019). Moreover, levorphanol is the levorotatory isomer of racemic 3-hydroxy-N-methylmorphinan (Dromoran®) and named as Levo-Dromoran®. DXM is named according to IUPAC rules as (+)-3-methoxy-17-methyl-9α,13α,14α-morphinan. It is also the d-isomer of methorphan (racemic mixture), but unlike the l-isomer, it does not have opioid activity. Methorphan presents as two isomeric forms, each with differing pharmacology and effects with respect to its two enantiomers. The DXM is used as an antitussive drug in cough medicines (and in high doses, it is a dissociative hallucinogen), whereas the levorotatory enantiomer levomethorphan, a prodrug of levorphanol, is a strong opioid analgesic that is listed as a schedule II drug in the USA (Wong and Sunshine 1996; Bortolotti et al. 2013; Gudin et al. 2016). Levorphanol binding affinity for the mu (MOR; µ) opioid receptor, 0.42 nM, is greater than the affinity of morphine, 1.24 nM and also presents longer t1/2 (Bortolotti et al. 2013). As DXM is approved for use in OTC drugs, accurate control of enantiomeric purity is essential to assure that commercial DXM preparations do not contain the l-enantiomer.