[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Opioids and antagonists](https://durgical.com/en/pharmacology/classes/opioids-and-antagonists/) › Levorphanol # Levorphanol ## Opioids and antagonists? Opioids and antagonists ## High alert? An error with this medicine can cause serious harm: double checks and protocols are used. A full μ-opioid agonist with a long half-life for severe pain. It builds up over the first days, so sedation and breathing are watched closely. Updated Nov 1, 2026 ## Quick facts **Group** [Opioids and antagonists](https://durgical.com/en/pharmacology/classes/opioids-and-antagonists/) **Target** μ-opioid receptor **Key effects** Constipation · Nausea and vomiting **Monitor** Respiratory rate · Pain score No doses: the clinician sets them by the current guideline. On this page - The basics Mechanism of action - Indications - Adverse effects - Pharmacokinetics - Memory aid - Clinical What the labels mean - Safety Contraindications - Key interactions - What is monitored - Administration and safety - Pregnancy and breastfeeding - Nursing care - Study Test yourself - Connections Connections ## Mechanism of action ◎**μ-opioid receptor**Levorphanol ⓘ The figure shows morphine in the μ receptor; levorphanol, a morphinan, occupies the same site. **Target in 3D:** μ-opioid receptor. PDB structure 8EF6 (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/8EF6) · Drag to rotate · pinch to zoom Levorphanol is a full opioid agonist, relatively selective for the μ receptor, that binds other opioid receptors at higher doses. Its long half-life makes the drug and its inactive glucuronide accumulate with repeated doses. - Activates μ-opioid receptors (others at high doses) - Pain transmission and perception fall - Long half-life: levels keep rising for about three days ## Indications - Pain severe enough to need an opioid when other treatments are not enough ## Adverse effects ### Common - Constipation - Nausea and vomiting - Sleepiness and tiredness - Headache and dizziness ### Serious (rare, important) - Life-threatening respiratory depression - Addiction, abuse and misuse; fatal accidental ingestion, especially by children - Deep sedation, coma and death when combined with benzodiazepines, alcohol or other depressants - Neonatal opioid withdrawal syndrome after prolonged use in pregnancy - Delayed overdose from accumulation in the first days ## Contraindications - Significant respiratory depression - Acute or severe asthma without monitoring or resuscitation equipment - Known or suspected bowel obstruction, including paralytic ileus ## Key interactions **Benzodiazepines, alcohol and other CNS depressants** Additive sedation and respiratory depression, with risk of death **Serotonergic drugs (SSRIs, SNRIs, tricyclics, MAO inhibitors, tramadol)** Serotonin syndrome **Mixed agonist-antagonist or partial agonist opioids (such as buprenorphine)** Less pain relief and possible withdrawal ## What is monitored - Respiratory rate, sedation level and oxygen saturation, above all at the start and after dose changes - Pain score, bowel habit and signs of misuse - Sedation over the first days, when levels are still rising ## Administration and safety - Controlled medicine (Schedule II in the United States): counted, stored locked and documented - Oral tablets are swallowed whole; crushing or dissolving them for injection is dangerous - Dose changes are spaced out because the drug accumulates ## Pregnancy and breastfeeding Prolonged use in pregnancy can cause neonatal opioid withdrawal syndrome; it is not recommended during labour. ## Nursing care - Check breathing rate and sedation before each dose and hold the drug if the patient is hard to wake - Keep naloxone available and know the local overdose protocol - Start a bowel regimen and watch for urinary retention - Teach safe storage away from children, no alcohol and no driving while drowsy ## Pharmacokinetics **Metabolism** In the liver to an inactive glucuronide, which accumulates with chronic use **Elimination** The glucuronide is excreted by the kidneys **Half-life** Long, about 11 to 16 hours ## Memory aid Levorphanol: «LEVel keeps rising» – long half-life, accumulates for days, like methadone. ## Test yourself Think of the answer, then tap the question to see it. ## Why is levorphanol watched closely over the first days? Its long half-life makes it accumulate, so sedation and respiratory depression can appear late. ## Is its glucuronide metabolite active? No; it is inactive but accumulates and is excreted by the kidneys. ## Which opioid shares this accumulation problem? Methadone. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/levorphanol/) [More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology) ## What the labels mean **High alert** An error with this medicine can cause serious harm: double checks and protocols are used. ## Connections ## Related drugs 4 - [Methadone](https://durgical.com/en/pharmacology/methadone/) - [Morphine](https://durgical.com/en/pharmacology/morphine/) - [Oxymorphone](https://durgical.com/en/pharmacology/oxymorphone/) - [Naloxone](https://durgical.com/en/pharmacology/naloxone/) [← Back to the class: Opioids and antagonists](https://durgical.com/en/pharmacology/classes/opioids-and-antagonists/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [DailyMed - LEVORPHANOL TARTRATE tablet](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=113a713f-830b-481c-bfa6-d44e3ac27f80) (DailyMed (U.S. National Library of Medicine), 2026); [Levorphanol: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a682020.html) (MedlinePlus (U.S. National Library of Medicine), 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/levorphanol/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/levorphanol/