Short answer: Levorphanol is a potent, long-acting prescription opioid for severe pain. It is a Schedule II controlled substance. Besides activating opioid receptors, it blocks NMDA receptors and the reuptake of serotonin and norepinephrine, which may help nerve pain, but its long half-life means it can build up over several days.
Key takeaways
- What it is: Levorphanol is an opioid agonist with nmda antagonist activity and a Schedule II controlled substance in the US.
- Main uses: Severe pain.
- Timing: effects start in 10 to 60 minutes and last 6 to 8 hours.
- Most dangerous mix: Benzodiazepines (alprazolam, diazepam, clonazepam), which can cause profound sedation, slowed breathing, coma, death.
- Naloxone: it reverses an overdose.
- Dependence risk: High.
- Legal route: only with a prescription from a DEA-registered clinician, filled by a licensed pharmacy.
What is levorphanol?
Levorphanol is approved for pain severe enough to require an opioid when other treatments are not enough. Pain specialists sometimes choose it when other opioids have failed or for nerve-related pain.
Because its half-life is about twice as long as its pain relief, the drug accumulates with repeated doses. Full effects of a dose change may not be seen for 3 days, so doses are increased slowly.
Quick facts
| Fact | Levorphanol |
|---|---|
| Generic name | Levorphanol tartrate |
| Brand names | Levo-Dromoran (discontinued); generic only |
| Drug class | Opioid agonist; NMDA receptor antagonist |
| US legal status | Schedule II, prescription only |
| Approved uses | Pain severe enough to require an opioid |
| Forms | Tablets (2 mg, 3 mg) |
| Onset | 10 to 60 minutes |
| Half-life | 11 to 16 hours, much longer than its pain relief |
| Reversal agent | Naloxone (repeat doses may be needed) |
How long does levorphanol last?
- Starts working: 10 to 60 minutes
- Effects last: 6 to 8 hours
- Half-life: 11 to 16 hours, much longer than its pain relief
Most of a dose is cleared in 3 to 4 days, but specific testing is needed to detect it.
Timing varies with the dose, the form, how it is taken, liver and kidney function, age, and other drugs taken at the same time.
What are the biggest risks of levorphanol?
The FDA requires boxed warnings, its strongest, on levorphanol products, including:
- Addiction, abuse, and misuse, which can lead to overdose and death.
- Life-threatening slowed breathing, especially when starting treatment or after a dose increase.
- Accidental ingestion, especially by children, can cause a fatal overdose.
- Use with benzodiazepines or other central nervous system depressants, including alcohol, can cause profound sedation, slowed breathing, coma, and death.
Common side effects include nausea, vomiting, constipation, drowsiness, dizziness, and confusion.
Accumulation: sedation and slowed breathing can appear days after starting or after a dose increase, as the drug builds up.
What should you never mix with levorphanol?
| Combined with | What happens | Label guidance |
|---|---|---|
| Benzodiazepines (alprazolam, diazepam, clonazepam) | Profound sedation, slowed breathing, coma, death | Boxed warning; avoid unless no alternative |
| Alcohol | Stronger sedation and slowed breathing | Avoid |
| Gabapentin, pregabalin, sleep medicines, muscle relaxants | Additive sedation and breathing problems | Use caution; lower doses |
| MAO inhibitors and other serotonin drugs | Possible serotonin syndrome or opioid toxicity | Avoid MAOIs; use caution with others |
| Mixed agonist-antagonists and buprenorphine | Reduced pain relief; can trigger withdrawal | Avoid |
Check any combination with the DoseUses combination checker or ask a pharmacist.
What are the signs of a levorphanol overdose, and what should you do?
Levorphanol overdose causes deep sleepiness, pinpoint pupils, and slow or stopped breathing. Because it lasts so long, breathing can slow again after naloxone wears off.
If someone may have overdosed
- Call 911 if the person is unresponsive, cannot be woken, has blue or gray lips, or is breathing slowly or not at all.
- Give naloxone (Narcan or a generic nasal spray, sold without a prescription) into one nostril. If there is no response after 2 to 3 minutes, give another dose.
- If you are trained, give rescue breaths. Otherwise place the person on their side so they do not choke.
- Stay with them. Naloxone can wear off before levorphanol does, so the overdose can return even after the person wakes up.
- Most states have Good Samaritan laws that protect people who call 911 for an overdose from some drug charges.
What is levorphanol withdrawal like, and how long does it last?
People who take levorphanol regularly for more than a few weeks become physically dependent, even when they take it exactly as prescribed. Dependence is not the same as addiction, but it means stopping suddenly causes withdrawal.
- 12 to 36 hoursEarly symptomsAnxiety, restlessness, yawning, sweating, runny nose, watery eyes, and muscle aches.
- Days 2 to 5Peak withdrawalDiarrhea, stomach cramps, nausea and vomiting, goosebumps, dilated pupils, fast heartbeat, and strong cravings. Rarely dangerous in healthy adults, but dehydration can be serious.
- 1 to 2 weeks, then weeksLingering symptomsPoor sleep, low mood, low energy, and cravings can continue for weeks. Tolerance falls quickly, which raises the risk of overdose if use restarts.
See the withdrawal timelines and the full levorphanol withdrawal guide.
Is levorphanol legal?
In the United States, levorphanol is a Schedule II controlled substance. The only legal way to get it is with a prescription from a clinician registered with the Drug Enforcement Administration (DEA), filled by a licensed pharmacy. Depending on state law, that can be a physician, nurse practitioner, or physician assistant.
- Refills: Schedule II prescriptions cannot be refilled. A prescriber can issue several prescriptions at once, each dated with the earliest fill date, for up to a 90-day supply.
- Telehealth: federal flexibilities let DEA-registered clinicians prescribe Schedule II to V medicines after a telemedicine visit, without a prior in-person exam, through December 31, 2026. A permanent DEA rule was under final review in late 2026. State rules can be stricter.
- Monitoring: prescribers and pharmacists in most states check a prescription drug monitoring program, a database of controlled-substance prescriptions, before prescribing or dispensing.
Outside the United States
| Country | Status |
|---|---|
| United Kingdom | Class A |
| Canada | Schedule I of the Controlled Drugs and Substances Act |
| International | Schedule I of the 1961 Single Convention on Narcotic Drugs |
Frequently asked questions about levorphanol
Is levorphanol stronger than morphine?
Yes. It is several times more potent than morphine per milligram by mouth.
Why is levorphanol used for nerve pain?
It also blocks NMDA receptors and the reuptake of serotonin and norepinephrine, which may help some types of nerve pain, though evidence is limited.
Why does levorphanol build up in the body?
Its half-life is 11 to 16 hours, much longer than the 6 to 8 hours of pain relief, so repeated doses accumulate.
Is levorphanol hard to find?
It is made by few manufacturers, so some pharmacies must order it.
How long does levorphanol stay in your system?
Most of a dose is cleared in 3 to 4 days, but specific testing is needed to detect it.
Sources
- levorphanol prescribing information, DailyMed, US National Library of Medicine.
- FDA warns about serious risks and death when combining opioid pain or cough medicines with benzodiazepines, US Food and Drug Administration, 2016.
- Information about naloxone and nalmefene, US Food and Drug Administration.
- CDC Clinical Practice Guideline for Prescribing Opioids for Pain, 2022, Centers for Disease Control and Prevention, MMWR.
- Controlled Substance Schedules, DEA Diversion Control Division.
- 21 CFR 1306.12, Refilling prescriptions; issuance of multiple prescriptions (Schedule II), Electronic Code of Federal Regulations.
- Prescribing controlled substances via telehealth, US Department of Health and Human Services.
- BeSafeRx: Your Source for Online Pharmacy Information, US Food and Drug Administration.
This guide summarizes the sourced DoseUses Levorphanol profile, written from FDA labels, DEA rules, and federal health agencies. It is educational and is not medical advice. Last updated October 5, 2026.
