Short answer: Lorazepam (Ativan) is an intermediate-acting benzodiazepine used for anxiety, short-term insomnia caused by anxiety, and, by injection, for status epilepticus and sedation before procedures. It is a Schedule IV controlled substance.
Key takeaways
- What it is: Lorazepam is an intermediate-acting benzodiazepine and a Schedule IV controlled substance in the US.
- Main uses: Anxiety; seizures; sedation.
- Timing: effects start in 20 to 30 minutes and last 6 to 8 hours.
- Most dangerous mix: Opioids (oxycodone, fentanyl, codeine), which can cause slowed breathing, coma, death.
- Naloxone: it does not reverse this drug, but give it whenever opioids could be involved.
- Dependence risk: High.
- Legal route: only with a prescription from a DEA-registered clinician, filled by a licensed pharmacy.
What is lorazepam?
Lorazepam tablets are approved for anxiety disorders and short-term relief of anxiety, including anxiety with depression. Injected lorazepam is a first-line treatment for status epilepticus and is used for sedation before surgery.
Because lorazepam is cleared by glucuronidation rather than CYP liver enzymes, it has fewer drug interactions and is often preferred in older adults and people with liver disease.
Quick facts
| Fact | Lorazepam |
|---|---|
| Generic name | Lorazepam |
| Brand names | Ativan, Loreev XR |
| Drug class | Intermediate-acting benzodiazepine |
| US legal status | Schedule IV, prescription only |
| Approved uses | Anxiety; insomnia due to anxiety; status epilepticus and pre-procedure sedation (injection) |
| Forms | Tablets, extended-release capsules, oral concentrate, injection |
| Onset | 20 to 30 minutes by mouth |
| Half-life | About 12 hours |
| Broken down by | Glucuronidation (no CYP enzymes) |
How long does lorazepam last?
- Starts working: 20 to 30 minutes
- Effects last: 6 to 8 hours
- Half-life: About 12 hours
Its half-life is about 12 hours. Urine tests usually detect it for 3 to 6 days.
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 lorazepam?
The FDA requires boxed warnings, its strongest, on lorazepam products, including:
- Taking benzodiazepines with opioids can cause profound sedation, slowed breathing, coma, and death.
- Benzodiazepines can be misused and can lead to addiction, which raises the risk of overdose and death.
- Regular use can cause physical dependence. Stopping suddenly or cutting the dose quickly can cause withdrawal reactions, including seizures, that can be life-threatening.
Common side effects include sedation, dizziness, weakness, and unsteadiness. Memory problems for events after a dose can occur.
What should you never mix with lorazepam?
| Combined with | What happens | Label guidance |
|---|---|---|
| Opioids (oxycodone, fentanyl, codeine) | Slowed breathing, coma, death | Boxed warning; avoid unless no alternative |
| Alcohol | Stronger sedation and slowed breathing | Avoid |
| Other sedatives, sleep medicines, gabapentinoids | Additive drowsiness and impaired coordination | Use caution |
| Valproate | Raises lorazepam levels | Reduce lorazepam dose by about half |
| Probenecid | Raises lorazepam levels | Reduce dose |
Check any combination with the DoseUses combination checker or ask a pharmacist.
What are the signs of a lorazepam overdose, and what should you do?
Lorazepam overdose causes drowsiness, confusion, lethargy, poor coordination, low blood pressure, and coma. Combined with opioids or alcohol, breathing can stop.
If someone may have overdosed
- Call 911 if the person is unresponsive, hard to wake, or breathing slowly.
- For advice when the person is awake and stable, call Poison Help at 1-800-222-1222 (US, free, 24 hours).
- If opioids could be involved, including pills not from a pharmacy, give naloxone if you have it. Naloxone does not reverse lorazepam, but it will not harm the person.
- Stay with the person and place them on their side if they are drowsy or vomiting.
What is lorazepam withdrawal like, and how long does it last?
People who take lorazepam regularly, even as prescribed, can become physically dependent within weeks. With an intermediate half-life, withdrawal typically begins within a day or two of the last dose.
- Days 1 to 2Symptoms beginRebound anxiety, insomnia, restlessness, sweating, and tremor.
- Weeks 1 to 4Acute withdrawalPanic, irritability, muscle pain, nausea, sensitivity to light and sound, and in severe cases seizures or delirium.
- MonthsProtracted symptoms in some peopleA minority have lingering anxiety, poor sleep, low mood, or tingling that can last weeks to more than 12 months.
See the withdrawal timelines and the full lorazepam withdrawal guide.
Is lorazepam legal?
In the United States, lorazepam is a Schedule IV 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: a Schedule IV prescription can be refilled up to five times within six months of the date it was written. After that, a new prescription is needed.
- 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 C; prescription only |
| Canada | Schedule IV (targeted substance); prescription only |
| Australia | Schedule 4 prescription medicine |
| International | Schedule IV of the 1971 Convention on Psychotropic Substances |
Frequently asked questions about lorazepam
Is lorazepam stronger than alprazolam?
Roughly 1 mg of lorazepam equals about 0.5 mg of alprazolam. Lorazepam lasts somewhat longer.
Why is lorazepam used in hospitals?
It works quickly by injection, is a first-line treatment for prolonged seizures, and has few drug interactions.
How long does lorazepam stay in your system?
Its half-life is about 12 hours. Urine tests usually detect it for 3 to 6 days.
Is lorazepam safe for older adults?
It is preferred over some benzodiazepines because it does not build up, but all benzodiazepines raise the risk of falls, confusion, and fractures in older adults.
Sources
- Ativan (lorazepam) 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.
- FDA requiring Boxed Warning updated to improve safe use of benzodiazepine drug class, US Food and Drug Administration, 2020.
- Joint Clinical Practice Guideline on Benzodiazepine Tapering, American Society of Addiction Medicine, 2025.
- Controlled Substance Schedules, DEA Diversion Control Division.
- 21 CFR 1306.22, Refilling of prescriptions (Schedules III and IV), 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 Lorazepam profile, written from FDA labels, DEA rules, and federal health agencies. It is educational and is not medical advice. Last updated October 5, 2026.
