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Lorazepam Facts

Depressant; Anxiolytic; Benzodiazepine; GABA-A receptor positive allosteric modulator

Description

Lorazepam — also known as Ativan — is a synthetic depressant of the benzodiazepine class. It amplifies GABA, the brain's main inhibitory signal, quieting activity across the nervous system.[1][2]

Subjective effects include anxiety suppression, sedation, anterograde amnesia, muscle relaxation, and emotional suppression. The experience is a broad quieting — cognitive activity slows, emotional reactivity flattens, and physical tension dissolves into a heavy, indifferent calm.

Lorazepam produces rapid physical dependence and ranks among the benzodiazepines with the highest withdrawal severity,[3] though death from the compound alone is extremely rare.[4] The dominant combination risk is opioids — both suppress breathing independently, and together they carry an FDA Black Box Warning.[5]

Dose and durationby route · individual sensitivity varies

Oral(mg)
Threshold< 0.1 mgLight0.25 – 0.5 mgCommon0.5 – 1.5 mgStrong1.5 – 2 mgHeavy2+ mg

Starts in 15 – 45 minLasts 6 – 8 hoursAfter-effects 6 – 24 hours

Body and dependence

Acute toxicity
Low
Chronic toxicity
Moderate
Physical dependence
High
Psychological dependence
High
Withdrawal
Life-threatening · fatal · medical supervision
Compulsive redosing
Moderate

Tolerance

Builds
Rapid
Fully resets after
11 days
Carries over to
benzodiazepines; ethanol; phenobarbital; barbiturates; Z-drugs

Effectslikely at a common dose

Perception
Dreaming suppression; +4 possible, including Vestibular distortion, Spatial disorientation, Visual acuity suppression
Body
Muscle relaxation; Sedation; +8 possible, including Motor control impairment, Dizziness, Heart rate perception changes
Thinking
Cognitive impairment; Focus suppression; Information processing suppression; +13 possible, including Decision impairment, Memory suppression, Analysis suppression
Feeling
Anxiety suppression; +1 possible
Self
none likely · 4 possible, including Communication suppression
Time
none likely · 2 possible, including Temporal disorientation

Who shouldn't take it

Absolute
Severe respiratory insufficiency; Sleep apnea syndrome; Hypersensitivity to benzodiazepines; Neonates and premature infants (injectable formulation); Acute narrow-angle glaucoma; Intra-arterial injection (IV formulation)
Relative
Active substance use disorder; Hepatic encephalopathy; Pregnancy (1st and 3rd trimester); Elderly (≥65 years); Concurrent opioid therapy; IV lorazepam with metronidazole

Combinations60 recorded

Lethal (1)
Opioids
Dangerous (21)
Alpha-2 adrenergic receptor antagonist; Antipsychotics; Atypical antipsychotics; Benzodiazepines; Buprenorphine, Kratom; Cannabis, THC; Clonidine, Guanfacine; Gabapentin, Pregabalin; GHB, Baclofen; GHB, GBL; Local anesthetics; Naltrexone; SNRIs; Stimulants; Synthetic cannabinoids; Ibogaine; Ketamine, DXM, PCP; MAOIs; NSAIDs; Poppers (Alkyl nitrites); Poppers, Nitrates
Caution (26)
See full page: psychedex.org/substances/lorazepam
Not graded (12)
Not listed never means safe.

Seek help immediately if

  • Extreme drowsiness — can't stay awake or be roused
  • Confusion, slurred speech, severe loss of coordination
  • Slow, shallow, or irregular breathing
  • Unconsciousness / unresponsive; limp, floppy body
  • Blue lips or fingertips
  • Vomiting while sedated (choking / aspiration risk)
  • Cold, clammy skin; weak pulse

What to do

  1. Try to wake them — shout, firm sternal rub
  2. If unresponsive or breathing is impaired, call emergency services
  3. Place them in the recovery position — critical, they can choke on vomit
  4. Monitor breathing continuously; be ready to give rescue breaths / CPR
  5. Never leave them alone to "sleep it off"
  6. Do not give other drugs, stimulants, or more depressants

Most depressant overdoses resolve with airway protection, breathing support, and monitoring. The danger is respiratory depression and choking on vomit — sharply worse when combined with opioids or alcohol. GHB/GBL overdoses often involve sudden deep unconsciousness and may self-resolve, but airway protection is essential.

988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE

Version r1.a1 · Not medical advice

References

  1. [1]
    ^Sankar R (2012) GABA(A) receptor physiology and its relationship to the mechanism of action of the 1,5-benzodiazepine clobazam. — CNS drugs doi:10.2165/11599020-000000000-00000
  2. [2]
    ^Ghiasi N, Bhansali RK, Marwaha R (2024) Lorazepam - StatPearls — StatPearls [Internet] Link
  3. [3]
    ^Cosci F, Chouinard G (2020) Acute and Persistent Withdrawal Syndromes Following Discontinuation of Psychotropic Medications — Psychotherapy and Psychosomatics doi:10.1159/000506868
  4. [4]
    ^Allen MD, Greenblatt DJ, LaCasse Y, Shader RI (1980) Pharmacokinetic study of lorazepam overdosage — The American journal of psychiatry PMID:6108079
  5. [5]
    ^Matheson C, Vucic C, Dumbrell J, Robertson R, et al. (2024) Clinical Outcomes of Benzodiazepine Prescribing for People Receiving Opioid Agonist Treatment: A Systematic Review — Pharmacy (Basel, Switzerland) doi:10.3390/pharmacy12050152
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