What Is Lorazepam (Ativan) and How Does It Work?

Lorazepam is a prescription medical treatment used to manage anxiety. Lorazepam belongs to a class of drugs known as benzodiazepines which act on the brain and nerves (central nervous system) to produce a calming effect that relieves symptoms of anxiety. This drug works by enhancing the effects of a certain natural chemical in the body (GABA). This medication may also be used as a treatment for short-term insomnia. Insomnia is a medical condition that involves poor sleep quality and/or quantity of sleep during a period of time.

Lorazepam is not a narcotic but may produce narcotic effects. It may have adverse reactions when taken while using antihistamine medications.

  • This medication must be prescribed by a doctor and is available by prescription only.
  • This medication is available as an oral drug or by injection.
  • Your doctor or healthcare provider should advise you that while taking this drug or other benzodiazepines, you should not consume alcohol.
  • Side effects and symptoms that are most commonly associated with this medicine are drowsiness and lightheadedness.
  • Read the drug information leaflet that accompanies the prescription as well as every time the prescription is refilled. There may be new health information.
  • Patients taking this drug should alert their doctors about any problems from the use of this medication and any troublesome side effects.
  • Lorazepam is available under the following different brand names: Ativan.

What Are Dosages of Lorazepam?

Dosages Consideratioins - Should Be Given As Follows: Anxiety Disorders
  • Initial: 2-3 mg oral tablet once every 8-12 hours as needed; not to exceed 10 mg/day
  • Maintenance: 2-6 mg/day taken orally divided once every 8-12 hours
  • Geriatric: Lower initial dose recommended; 1-2 mg orally divided once every 8-12 hours
Short-Term Treatment of Insomnia
  • 2-4 mg taken orally at bedtime
  • Geriatric: Lower initial dose recommended; 0.5-1 mg orally at bedtime, increase as needed. To avoid over-sedation, initial daily dose should not exceed 2 mg
Preoperative Sedation, Anxiety Relief, & Anterograde Amnesia
  • 0.05 mg/kg intramuscularly (IM) for 1 dose; 2 hours before surgery; not to exceed 4 mg (2 mg in elderly), OR
  • 0.044 mg/kg intravenously (IV) for 1 dose; 15-20 minutes before surgery; not to exceed 4 mg (2 mg in elderly)
Status Epilepticus - Adult
  • Usual 4 mg/dose slow IV at 2 mg/min
  • If seizure persists after 5-10 min, administer 4 mg IV again
Status Epilepticus (Off-label) - Pediatric
  • Infants and children: 0.05-0.1 mg/kg IV over 2-5 minutes; not to exceed 4 mg/dose; may repeat every 10-15 minutes as needed
  • Alternatively, 0.1 mg/kg at slow IV rate not to exceed rate of 2 mg/minute; not to exceed dose of 4 mg
  • Adolescents: 4 mg slow IV; if seizure persists after 10-15 minutes, administer 4 mg IV again
Anxiolytic/Sedation in ICU (Off-label)
  • Intubated and mechanically ventilated patients
    • 0.02-0.04 mg/kg IV
    • 0.02-0.06 mg/kg intermittent IV once every 2-6 hours as needed, OR
    • 0.01-0.1 mg/kg/hour continuous IV; not to exceed 10 mg/hour

Children: 0.05 mg/kg orally once every 4-8 hours; not to exceed 2 mg

Chemotherapy-Induced Nausea/Vomiting (Off-label)
  • 0.5-2 mg orally or intravenously (IV) once every 6 hours; as needed thereafter
  • Children 2 years and older: 0.025-0.05 mg/kg intravenously (IV) once every 6 hours as needed; not to exceed 2 mg
Chronic Insomnia (Off-label)
  • 2-4 mg orally bedtime
Dosing Considerations
  • Intravenously (IV): Monitor respirations every 5-15 minutes and before each repeated IV dose
  • Geriatric: When higher dose indicated, increase evening dose before daytime doses
Dosing Modifications
  • Renal impairment
    • Orally: Adjustment not necessary
    • IV/IM: Use with caution in mild-to-moderate impairment; not recommended in severe impairment or renal failure
    • IV/IM (prolonged periods or high doses): Monitor; risk of propylene glycol toxicity
  • Hepatic impairment
    • Orally: No dose adjustment recommended in mild-to-moderate impairment; use with caution (may require lower dose) in severe impairment
    • IV/IM: Use with caution in mild-to-moderate impairment; not recommended in severe impairment of hepatic failure

What Are Side Effects Associated with Using Lorazepam (Ativan)?

Side effects of lorazepam include:

  • Sedation
  • Dizziness
  • Unsteadiness
  • Weakness
  • Fatigue
  • Drowsiness
  • Amnesia
  • Confusion
  • Disorientation
  • Depression
  • Suicidal ideation/attempt
  • Spinning sensation (vertigo)
  • Sleep apnea
  • Extrapyramidal symptoms (muscle spasms, restlessness, jerky movements)
  • Loss of control of bodily movements (ataxia)
  • Respiratory depression
  • Tremor
  • Convulsions/seizures
  • Visual disturbances
  • Difficulty speaking
  • Low blood pressure (hypotension)
  • Change in libido, impotence
  • Yellowing of skin or eyes (jaundice)
  • Hypersensitivity reactions
  • Nausea
  • Constipation
  • Change in appetite
  • Anxiety, excitation, agitation, hostility, aggression, rage
  • Blood dyscrasias
  • Increased bilirubin
  • Increased liver transaminases
  • Increase in ALP

This document does not contain all possible side effects and other serious side effects may occur. Check with your doctor for additional health information about common problems or negative side effects associated with this medicine. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What Other Drugs Interact with Lorazepam (Ativan)?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions, potential problems or health risks, and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before seeking medical advice from your doctor, health care provider or pharmacist first. To do so may have pose adverse dangers to your health.

Severe Interactions of Lorazepam (Ativan) include:

  • sodium oxybate

Serious Interactions of Lorazepam (Ativan) include:

Lorazepam (Ativan) has moderate interactions with at least 191 different drugs.

Lorazepam (Ativan) has mild interactions with at least 36 different drugs.

This document does not contain all possible interactions or health implications. Therefore, before using this medicine, tell your doctor or pharmacist of all the medications you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your doctor if you have health questions or concerns.

What Are Warnings and Precautions for Lorazepam (Ativan)?


Risks From Concomitant Use With Opioids

  • Comitant use of benzodiazepines and opioids may result in profound sedation, respiratory decline, coma, and death
  • Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate
  • Limit dosages and durations to the minimum required
  • Follow patients for signs and symptoms of respiratory decline and sedation

This medication contains lorazepam Do not take Ativan if you are allergic to this medication or any ingredients contained in this drug

Keep out of reach of children In case of overdose, get medical help or contact a Poison Control Center immediately


  • Documented hypersensitivity
  • Acute narrow angle glaucoma
  • Intra-arterial administration
  • Severe respiratory decline
  • Sleep apnea

Effects of Drug Abuse

  • Prolonged use may lead to physical and psychological dependence especially in those with history of alcohol or drug abuse; potential for dependence is decreased with short-term treatment (eg, 2-4 weeks)
  • Your doctor may evaluate your health and the need for continued treatment prior to extending the use of this medicine

Short-Term Effects

  • See “What Are Side Effects Associated with Using Lorazepam?”

Long-Term Effects

  • Do not withdraw abruptly after prolonged use; terminate dosage gradually
  • See “What Are Side Effects Associated with Using Lorazepam?”


  • Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death
  • Advise about the potential of respiratory depression and sedation when this medication is used with opioids; advise patients not to drive or operate heavy machinery until the effects of concomitant use with the opioid have been determined There may also be difficulty performing normal tasks
  • Use in pregnancy may be acceptable Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk
  • Not recommended when lactating as lorazepam enters breast milk
  • Potentially fatal respiratory depression
  • Not recommended for use in patients with primary depressive disorder or psychosis
  • Injection contains benzyl alcohol associated with potentially fatal "gasping syndrome" in neonates
  • Use caution in patients with history of suicide attempt or drug abuse
  • Use caution in patients with impaired gag reflex
  • May cause CNS decline and may affect breathing, impairing physical and mental abilities; caution patients to not operate dangerous machinery or motor vehicles
  • Anterograde amnesia reported with use
  • Use caution with respiratory disease, including COPD or sleep apnea
  • Hyperactive or aggressive behavior and other paradoxical reactions reported with use
  • Caution that tolerance for alcohol and other CNS depressant medications will be greatly reduced
  • General anesthetics and sedation drugs in young children and pregnant women:
    • Brain development
    • Prolonged or repeated exposure may result in negative effects on fetal or young children's brain development
    • Caution with use during surgeries or procedures in children younger than 3 years or in pregnant women during their third trimester
    • Assess the benefit ratio in these populations, especially for prolonged procedures (ie, greater than 3 hours) or multiple procedures

Pregnancy and Lactation

  • Only use lorazepam during pregnancy in LIFE-THREATENING emergencies when no safer drug is available
  • There is positive evidence of human fetal harm Minor tranquilizers should be avoided in first trimester of pregnancy, due to increased potential of congenital malformations Maternal use shortly before delivery is associated with floppy infant syndrome (good and consistent evidence)
  • Prenatal benzodiazepine exposure slightly increased oral cleft risk (limited or inconsistent evidence)
  • Lorazepam is excreted in human breast milk; it is not recommended for use while breastfeeding
  • Serious adverse effects, including central nervous system (CNS) and respiratory depression exists

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