Bedside Snapshot
- Use It For
- Status epilepticus with IV access; alcohol withdrawal seizures and withdrawal delirium; severe agitation in the ED (with haloperidol); preprocedure anxiolysis and amnesia
- Adult Dose
- Status epilepticus: 0.1 mg/kg slow IV (max 4 mg per dose); repeat once at 5 min if still seizing
- Alcohol withdrawal seizure: 2 mg IV once
- Severe agitation (ED): 2 mg IM or IV with haloperidol
- Pediatric Dose
- Status epilepticus: 0.1 mg/kg slow IV (max 4 mg per dose), repeat once at 5 min if still seizing. No IV: IM, intranasal or buccal midazolam. Contraindicated in premature infants
- Onset / Duration
- IV: 1–3 min / 6–8 hr, longer after repeated doses; IM: slower, peak level within 3 hr; PO: peak about 2 hr
- Do Not Give / Hold If
- Narrow-angle glaucoma; sleep apnea; severe respiratory insufficiency unless ventilated for anxiolysis or amnesia; intra-arterial use; premature infants; 2 benzodiazepine doses given. Still seizing: treat, airway ready
- Watch For
- Apnea and airway obstruction (SpO₂, EtCO₂); hypotension (BP every 5 min); sedation hiding ongoing seizures (EEG if not waking); propylene glycol toxicity with high doses (osmolar gap, acidosis)
- Reversal / Rescue
- Airway, O₂ and bag-valve mask first. Flumazenil 0.2 mg IV only for iatrogenic oversedation in a non-dependent patient; contraindicated after lorazepam for seizures
- Must Remember
- Two vial strengths (2 and 4 mg/mL): say the dose in mg and mL, dilute 1:1 and push no faster than 2 mg/min. Give one full dose, not small repeated pushes
Indications
Emergency & Prehospital
- Convulsive status epilepticus with IV access (FDA-labeled). Start once the seizure reaches 5 min. IV diazepam is the other first-line option. No IV access? IM midazolam is the one to reach for.
- Alcohol withdrawal seizure: one IV dose lowers the odds of an early repeat seizure (off-label)
ED / ICU / Transport
- Alcohol withdrawal and delirium tremens. Dosed by symptom-triggered protocol. It becomes the choice when liver disease limits the other benzodiazepines (off-label)
- Severe agitation in the ED: give it with haloperidol. It is not the preferred benzodiazepine here. Out of hospital, follow your EMS protocol (off-label)
- Preanesthetic sedation, anxiolysis and amnesia: adults (FDA-labeled)
- ICU sedation: intermittent doses for the patient in whom propofol or dexmedetomidine is unsuitable (off-label)
Other Uses
- Anxiety disorders and anxiety-related insomnia: short-term oral treatment (FDA-labeled)
- Catatonia, panic disorder, anticipatory chemotherapy nausea (off-label)
Dosing & Administration
Agitation, symptom-triggered alcohol withdrawal dosing and ICU sedation have no fixed house dose. Those rows run on the institutional protocol, so use that.
Available Forms
- Injection 2 mg/mL: 1 mL (2 mg) single-dose and 10 mL (20 mg) multiple-dose vials
- Injection 4 mg/mL: 1 mL (4 mg) single-dose and 10 mL (40 mg) multiple-dose vials
- Injection vehicle: polyethylene glycol 400, propylene glycol, 2% benzyl alcohol
- Tablets 0.5, 1, 2 mg; oral concentrate 2 mg/mL; Loreev XR 1–3 mg capsules (stable anxiety regimens)
High-Alert Medication: Two vial strengths. 2 mL is 4 mg of one and 8 mg of the other. The traps are fast or undiluted pushes, and doses stacked across home, EMS and ED. Say the dose in mg and mL. Dilute 1:1. Add up the earlier doses.
Adult Dosing
| Indication | Dose & Route | Repeat / Max | Notes |
|---|---|---|---|
| Status epilepticus, IV access | 0.1 mg/kg slow IV (max 4 mg per dose), no faster than 2 mg/min; 4 mg slow IV for most adults | Repeat the same dose once at 5 min if still seizing. Max 2 doses (8 mg) | High-alert Differs from FDA label: the label gives 4 mg (age 18 and over) and waits 10–15 minutes before a second 4 mg; E3 repeats once at 5 minutes (AES 2016, TREKK 2025). Count EMS and home doses. |
| Alcohol withdrawal seizure | 2 mg IV once | Single dose; then treat the withdrawal | Off-label (ED trial) |
| Alcohol withdrawal and withdrawal delirium | Per the institutional symptom-triggered (CIWA-Ar) protocol; IV when delirious | No fixed max: titrate to light somnolence. ASAM 2020 gives no lorazepam dose. Resistant withdrawal is uncontrolled after more than 150–200 mg diazepam or 30–40 mg lorazepam in 3–4 hr: add an adjunct and escalate | Off-label. ASAM prefers diazepam or chlordiazepoxide for front-loading. Adjuncts: phenobarbital, or propofol or dexmedetomidine in the ICU |
| Severe agitation | 2 mg IM or IV with haloperidol 5 mg IM | Reassess at 30 min before repeating; no labeled max | Off-label; doses from trials in the ACEP 2024 evidence table. ACEP (ED adults): haloperidol alone or with lorazepam; lorazepam alone is not endorsed. See droperidol |
| Preanesthetic sedation (IV) | 2 mg IV or 0.044 mg/kg, whichever is smaller, 15–20 min before the procedure | Up to 0.05 mg/kg (max 4 mg) when amnesia is wanted; usually no more than 2 mg over age 50 | Reduce other CNS depressant doses |
| Preanesthetic sedation (IM) | 0.05 mg/kg deep IM, at least 2 hr before the procedure | Max 4 mg | Give undiluted |
| Anxiety (oral) | 2–3 mg/day PO in 2–3 divided doses; anxiety-related insomnia: 2–4 mg PO at bedtime | Usual 2–6 mg/day; range 1–10 mg/day | Older or debilitated adults: start 1–2 mg/day |
| ICU sedation, ventilated | Intermittent IV doses per institutional ICU protocol, to a light-sedation target | No fixed max: titrate to the sedation goal | Off-label. 2025 SCCM PADIS update: conditionally favors dexmedetomidine over propofol; no recommendation for benzodiazepines for ICU anxiety. Taper after several days |
Pediatric Dosing
| Indication | Dose (per kg) & Route | Max Single / Max Total | Notes |
|---|---|---|---|
| Status epilepticus, IV access | 0.1 mg/kg slow IV or IO (off-label; NASEMSO v3.0 p. 102 gives 0.1 mg/kg IV or IO, max 4 mg). Rate no faster than 2 mg/min per the Ativan label | Max 4 mg per dose. Repeat the same dose once at 5 min if still seizing (max 2 doses; AES, TREKK 2025). The pediatric class I trial repeated a half dose at 5 min, which is acceptable. | High-alert Differs from FDA label: pediatric use is not established for status epilepticus. |
| Status epilepticus, no IV | — | Do not delay treatment to start an IV | |
| Agitation (off-label) | 0.05 mg/kg IV or IM | Max 2 mg per dose | NASEMSO v3.0 p. 60. Differs from FDA label: not established in children |
| Sedation or anxiety | Not established in children | — | Injection: under 18 yr; tablets: under 12 yr |
| Neonates | Not established in neonates | — | Contraindicated in premature infants (benzyl alcohol). Use the neonatal seizure protocol |
Weight-based dosing support: pediatric weight-based dosing and Broselow tape.
Preparation & Administration
- Dilution (IV): just before use, 1:1 with sterile water, 0.9% sodium chloride or D5W; mix by inversion, do not shake
- Push rate: no faster than 2 mg/min, with repeated aspiration
- Line: avoid intra-arterial or perivascular injection; stop and check the site if the patient reports pain
- IM: undiluted, deep into a large muscle. Levels rise slowly, which makes IM a poor choice for status epilepticus
Contraindications & Precautions
Contraindications
- Hypersensitivity to benzodiazepines or the injection vehicle
- Acute narrow-angle glaucoma; sleep apnea syndrome
- Severe respiratory insufficiency, except anxiolysis or amnesia in a mechanically ventilated patient (injection)
- Intra-arterial injection (arteriospasm and gangrene); premature infants (benzyl alcohol)
Status epilepticus is an indication, not a contraindication: left untreated, the seizure is the bigger respiratory threat. Ready the airway and ventilation gear before you need it.
Precautions
- Older, very ill or limited pulmonary reserve: hypoventilation and hypoxic arrest
- Hepatic or renal failure: the label steers you away from use. Use caution in mild to moderate disease
- Atypical absence status: brief tonic-clonic seizures have followed lorazepam
- Labor and cesarean delivery: parenteral use is not recommended here, because of neonatal sedation
- Pediatric neurotoxicity (label warning): repeated or prolonged (>3 hr) sedative exposure under age 3, or in the third trimester, is what the label warns about. Do not delay needed treatment over it
Hold / Reassess If
- Still seizing: do not hold the repeat dose over the low SpO₂, poor breathing or low BP the seizure itself causes. Ventilate, treat hypotension and start second-line therapy promptly
- Seizures stopped: no further benzodiazepine doses
- Two benzodiazepine doses given. Many protocols count home and EMS doses. Move to second-line therapy
- Seizures stopped, or sedation, agitation or withdrawal use (local protocol prompts, not guideline values): SpO₂ <90%, falling RR or EtCO₂ >50 mmHg: hold and support ventilation; SBP <90 mmHg: treat the cause before the next dose
FDA Boxed Warning:
- Opioids: the combination can cause profound sedation, respiratory depression, coma and death.
- Abuse, misuse and addiction: can end in overdose or death. Alcohol or other drugs are often involved.
- Dependence and withdrawal: stopping suddenly after use more often than recommended can cause life-threatening withdrawal. Taper it.
Adverse Effects & Toxicity
Common
- Sedation and drowsiness lasting 6–8 hr or longer; dizziness, ataxia, confusion
- Injection-site pain or burning (about 17% after IM and 1.6% after IV doses)
- Hypotension, somnolence and respiratory failure. These are the most common events in status epilepticus trials
Serious / Life-Threatening
| Effect | Recognition | Management |
|---|---|---|
| Respiratory depression, apnea, airway obstruction | Falling RR, SpO₂ <90%, rising EtCO₂, snoring or obstruction | Jaw thrust, O₂, bag-valve mask; intubate if needed. No flumazenil after seizure treatment |
| Hypotension | BP every 5 min after IV doses; worse with opioids or alcohol | Supine, IV fluid bolus, vasopressor per protocol; still seizing: support BP without delaying seizure control |
| Prolonged sedation masking seizures | Not waking after convulsions stop | Consider nonconvulsive status epilepticus; EEG; second-line drug |
| Intra-arterial injection | Pain, blanching or color change distal to the site | Stop the injection; urgent vascular surgery consult (arteriospasm can progress to gangrene) |
| Propylene glycol or polyethylene glycol toxicity | Anion-gap acidosis, rising lactate and osmolar gap, hypotension, acute kidney injury with high cumulative doses | Stop lorazepam, change agent, supportive care |
Overdose & Toxicity Management
- Signs: drowsiness, ataxia progressing to hypotonia, respiratory depression and coma. Vitals that are markedly abnormal point to a co-ingestant (alcohol, opioids)
- Immediate management: airway, ventilation, IV fluids; check glucose; contact Poison Control (1-800-222-1222)
- Flumazenil: adult overdose 0.2 mg IV, then 0.3 mg, then 0.5 mg every 1 min (max 3 mg). Pediatric sedation reversal (1 yr and older): 0.01 mg/kg (max 0.2 mg) every 1 min, max total 0.05 mg/kg or 1 mg. Do not give it after lorazepam for seizures. See its page for cautions
Monitoring
| Parameter | When / How Often | Target / Act If |
|---|---|---|
| Clinical: seizure activity and mental status | Continuously; record the time and mg of every dose | Still seizing after the second benzodiazepine dose: second-line drug. Not waking: consider nonconvulsive seizures (EEG) |
| Clinical: SpO₂, respiratory rate and waveform EtCO₂ | Continuous from the first dose until awake | SpO₂ <90%, shallow breathing or EtCO₂ >50 mmHg: reposition, O₂, bag-valve mask; keep treating the seizure |
| Clinical: BP and HR | Baseline, then every 5 min after each IV dose | SBP <90 mmHg: fluids and treat the cause; still seizing: support BP, do not delay seizure control |
| Clinical: withdrawal score and sedation | CIWA-Ar before each dose; RASS or CAM-ICU in delirium | Treat to light somnolence; do not use CIWA-Ar once delirious |
| Laboratory: glucose | Fingerstick in every seizure and altered patient | |
| Laboratory: repeated high IV doses | Anion-gap acidosis, hyperosmolality, a rising osmolar gap or creatinine: suspect propylene glycol toxicity; change agent |
Interactions & Compatibility
Clinically Significant Interactions
| Drug / Class | Effect | What To Do |
|---|---|---|
| Opioids (fentanyl, morphine, others) | Profound sedation, respiratory depression, coma, death (boxed warning) | Lowest effective doses; continuous SpO₂ and EtCO₂; naloxone reverses only the opioid |
| Alcohol, barbiturates (phenobarbital), antidepressants, MAOIs, phenothiazines, scopolamine | Additive CNS and respiratory depression; with scopolamine, more sedation, hallucinations and irrational behavior | Expect airway support when phenobarbital follows lorazepam |
| Haloperidol, clozapine, loxapine | Reports of apnea, coma, bradycardia, cardiac arrest and death (haloperidol); marked sedation and salivation (clozapine); stupor and hypotension (loxapine) | Combination is common for agitation: continuous monitoring and the lowest effective doses |
| Valproate, probenecid | Lorazepam clearance falls; levels about double (valproate) | Reduce lorazepam doses by 50% |
| Oral contraceptives | Lorazepam clearance about 3.7-fold higher; half-life 55% shorter | A higher dose may be needed |
| Flumazenil | Precipitated withdrawal and seizures | Avoid in dependent patients, seizure patients and mixed overdose |
Don't expect CYP450 interactions. Lorazepam clears by glucuronidation, not oxidation.
IV Compatibility
- Dilute only with sterile water, 0.9% sodium chloride or D5W; do not mix with other drugs in the same syringe.
- Verify with an institutional compatibility resource.
Special Populations
- Pediatrics: not FDA-established for status epilepticus or sedation. Watch for paradoxical excitation. Find doses in the Pediatric Dosing table.
- Neonates: contraindicated in premature infants, because of benzyl alcohol gasping syndrome. In neonates with asphyxia, the label says clearance and half-life shift sharply.
- Pregnancy: in observational studies, no clear link to major birth defects appears. Late-pregnancy or labor use can cause neonatal sedation, hypotonia and withdrawal, so monitor the newborn. National Pregnancy Registry for Psychiatric Medications: 1-866-961-2388. Don't withhold treatment for maternal status epilepticus. For a seizure in the third trimester or postpartum, NASEMSO v3.0 gives magnesium sulfate.
- Lactation: it passes into breast milk. Watch the infant for sedation, poor feeding and poor weight gain.
- Older Adults: clearance runs about 20% lower and sensitivity runs higher. Over age 50, IV doses bring deeper, longer sedation. Start oral doses at 1–2 mg/day. The AGS Beers Criteria lists benzodiazepines to avoid because of falls and delirium. Acute seizure and withdrawal treatment stays appropriate.
- Renal Impairment: no adjustment for single acute doses. Use caution with frequent doses. The propylene glycol vehicle builds up. Hemodialysis removes little lorazepam (about 8%).
- Hepatic Impairment: glucuronidation holds up, so single-dose clearance does not change in cirrhosis. Titrate carefully, because lorazepam can worsen hepatic encephalopathy.
- Obesity / Dosing Weight: there is no validated obesity adjustment. In adults over 40 kg, the 4 mg per-dose cap sets status epilepticus dosing.
Field & Transport Considerations
- Scope: IV and IM dosing sits with paramedic, RN and critical-care transport scope. What you may do varies by state and agency protocol.
- Storage & Stability: the label calls for refrigeration and light protection. On active EMS units (stored per agency policy) in a southwestern US summer, lorazepam dropped to 90.3% of labeled strength at 90 days and 86.5% at 120 days, while midazolam and diazepam stayed at 97% or more (see References). Refrigerate per label. Otherwise, follow agency beyond-use dating. It is Schedule IV, so keep it secured and counted.
- Carried Concentration: 4 mg is 2 mL of 2 mg/mL or 1 mL of 4 mg/mL. Say the vial strength out loud, then dilute 1:1 for IV use.
- No IV: don't delay for access. IM midazolam is at least as safe and effective as IV lorazepam for stopping prehospital seizures (NASEMSO v3.0).
- Handoff Essentials: seizure onset time; every benzodiazepine dose with time, route and mg; airway steps; glucose; response.
Clinical Pearls
Two doses, then move on: Repeat the full dose once, at 5 minutes. That is what AES allows. Plenty of protocols count home and EMS benzodiazepine doses against the two-dose limit. Still seizing 5 min after the second dose, or after an ESETT-adequate total of 4 mg? Start levetiracetam, fosphenytoin or valproate now. The AES 20-minute mark is the latest start, not the target.
Lorazepam vs midazolam vs diazepam (NREMT, CEN, FP-C):
- IV access: IV lorazepam or IV diazepam.
- No IV: reach for IM midazolam. It is at least as effective as IV lorazepam (NASEMSO v3.0).
The vehicle can poison: Propylene glycol makes up most of the injection. Large cumulative doses, the kind seen in resistant alcohol withdrawal or prolonged ICU use, lead to lactic acidosis, hyperosmolality, hyponatremia and kidney injury. Watch the osmolar gap, and switch agents.
After an alcohol withdrawal seizure: Within 6 hours, one 2 mg IV dose dropped the recurrence rate from 24% to 3%. Then find the cause and treat the withdrawal itself.
Pharmacology
Mechanism of Action
- Binds the benzodiazepine site of the GABA-A receptor → GABA grips its receptor more tightly → more chloride-mediated inhibition → anxiolysis, sedation, amnesia and seizure control.
- Intensity tracks receptor occupancy → dose-related CNS depression. It crosses the blood-brain barrier freely, so the IV effect arrives within minutes.
Pharmacokinetics
| Route | Onset | Peak | Duration |
|---|---|---|---|
| IV | 1–3 min | Amnesia greatest at 15–20 min | 6–8 hr; longer after repeated doses |
| IM | Slower than IV | Peak level within 3 hr; amnesia greatest at 2 hr | 6–8 hr |
| PO | — | About 2 hr; bioavailability 90% | — |
- Half-life: about 14 hr (±5 hr) after injection, about 12 hr orally; the glucuronide about 18 hr.
- Metabolism: hepatic glucuronidation (3-O-phenolic glucuronide); no CYP oxidation; enterohepatic recirculation.
- Active metabolites: none; lorazepam glucuronide is inactive.
- Elimination: urine, about 88% of a dose, mostly as the glucuronide.
- Protein binding / Vd: about 85–91% bound; Vd about 1.3 L/kg; crosses the blood-brain barrier and placenta.
Names & Classification
- Generic Name
- Lorazepam
- Brand Names
- Ativan (injection, tablets); Loreev XR (extended-release capsules). Generic injection, tablets and oral concentrate.
- Pharmacologic Class
- Benzodiazepine (GABA-A receptor positive allosteric modulator)
- Therapeutic Class
- Anticonvulsant; anxiolytic; sedative and amnestic
- Controlled Substance
- C-IV (DEA Schedule IV)
- ISMP High-Alert
- Yes: ISMP high-alert medication (moderate sedation agents, IV)
- Look-Alike / Sound-Alike
- LORazepam / ALPRAZolam; LORazepam / clonazePAM; LORazepam / Lovaza
References
- Hikma Pharmaceuticals USA Inc. (2023). ATIVAN Injection (lorazepam injection, USP), CIV: Prescribing information. DailyMed, U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5fc0e987-61c9-40c4-b0d5-fcea07c8733e
- Bausch Health US, LLC. (2025). ATIVAN (lorazepam) tablets, CIV: Prescribing information. DailyMed, U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=89057c93-8155-4040-acec-64e877bd2b4c
- Glauser, T., Shinnar, S., Gloss, D., et al. (2016). Evidence-based guideline: Treatment of convulsive status epilepticus in children and adults: Report of the Guideline Committee of the American Epilepsy Society (landmark guideline; current AES guideline). Epilepsy Currents, 16(1), 48–61. https://doi.org/10.5698/1535-7597-16.1.48
- National Association of State EMS Officials. (2022). NASEMSO National Model EMS Clinical Guidelines, Version 3.0 (Seizures, pp. 101–106; Agitated or Violent Patient, pp. 59–63). https://nasemso.org/docs.ashx?id=1444322
- TREKK/EIIC. (2025). Pediatric Status Epilepticus Algorithm, v1.1. https://cms.trekk.ca/wp-content/uploads/2025/05/2025_07_08-Status-Epilepticus-Algorithm-v1.1-Final-1.pdf
- American College of Emergency Physicians Clinical Policies Subcommittee on Severe Agitation. (2024). Clinical policy: Critical issues in the evaluation and management of adult out-of-hospital or emergency department patients presenting with severe agitation. Annals of Emergency Medicine, 83(1), e1–e30. https://doi.org/10.1016/j.annemergmed.2023.09.010
- Smith, M. D., Sampson, C. S., Wall, S. P., et al. (2024). Clinical policy: Critical issues in the management of adult patients presenting to the emergency department with seizures. Annals of Emergency Medicine, 84(1), e1–e12. https://doi.org/10.1016/j.annemergmed.2024.02.018
- American Society of Addiction Medicine. (2020). The ASAM clinical practice guideline on alcohol withdrawal management. Journal of Addiction Medicine, 14(3S Suppl 1), 1–72. https://doi.org/10.1097/ADM.0000000000000668
- Lewis, K., Balas, M. C., Stollings, J. L., et al. (2025). A focused update to the clinical practice guidelines for the prevention and management of pain, anxiety, agitation/sedation, delirium, immobility, and sleep disruption in adult patients in the ICU. Critical Care Medicine, 53(3), e711–e727. https://doi.org/10.1097/CCM.0000000000006574
- D'Onofrio, G., Rathlev, N. K., Ulrich, A. S., Fish, S. S., & Freedland, E. S. (1999). Lorazepam for the prevention of recurrent seizures related to alcohol (landmark trial). New England Journal of Medicine, 340(12), 915–919. https://doi.org/10.1056/NEJM199903253401203
- McMullan, J. T., Jones, E., Barnhart, B., et al. (2014). Degradation of benzodiazepines after 120 days of EMS deployment. Prehospital Emergency Care, 18(3), 368–374. https://doi.org/10.3109/10903127.2013.869642
- Ghiasi, N., Bhansali, R. K., & Marwaha, R. (2024). Lorazepam. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK532890/
Medical Disclaimer
- For Educational Purposes Only: This content is intended for educational reference and should not be used for clinical decision-making.
- Not a Substitute for Professional Judgment: Always consult your local protocols, institutional guidelines, and supervising physicians.
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