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WARNINGMIXING OR WITHDRAWAL CAN BE DANGEROUS
Ordinary doses in combination with other depressants can fatally stop breathing. After prolonged dependency, stopping suddenly can also cause seizures or delirium; seek medical help.
Lorazepam
Ativan, Temesta, Tavor, Orfidal, Lorsilan
Lorazepam is a short-acting depressant of the benzodiazepine classcitation needed. First marketed by Wyeth Pharmaceuticals in the United States in 1977, it is prescribed for the short-term treatment of anxiety, insomnia, acute seizures, and sedation of hospitalized patients. It is characterized by its relatively rapid clearance compared to many other benzodiazepines. Like all benzodiazepines, lorazepam carries a significant risk of physical dependence and habit formation1 with repeated use.
Dosage & Duration
Dosage
Doses are population estimates that vary widely between individuals.
Threshold~0.1 mg
Light0.1-0.5 mg
Moderate0.5-1.5 mg
Strong1.5-2 mg
Heavy2+ mg
Bioavailability
90%
Duration
Onset5-30 minutes
Peak1-3 hours
Offset4-8 hours
Total4-8 hours
Half-life
~8 hours
Subjective Effects
Legacy content. A statistically backed ontology from Mindstate Design Labs is coming soon.
Effects vary widely by individual, dose, and context.
Physical
The physical effects of lorazepam can be broken down into several components which progressively intensify proportional to dosage.
Cognitive
The cognitive effects of lorazepam can be broken down into several components which progressively intensify proportional to dosage. The general head space of lorazepam is described by many as one of intense sedation and decreased inhibition. It contains a large number of typical depressant cognitive effects.
Pharmacology
Pharmacodynamics
Lorazepam is a high-potency benzodiazepine that acts as a positive allosteric modulator at the benzodiazepine binding site of the GABA-A receptor.citation needed By binding to post-synaptic GABA-A ligand-gated chloride channels throughout the central nervous system, it increases the frequency of chloride ion channel opening in the presence of GABA, enhancing inhibitory neurotransmission through cellular hyperpolarization. Lorazepam is reported to have a relatively high affinity for the GABA-A benzodiazepine site compared to other benzodiazepines. Its anticonvulsant properties may additionally involve binding to voltage-dependent sodium channels.
Pharmacokinetics
Lorazepam is readily absorbed orally with an absolute bioavailability of approximately 90%,2 and is completely and rapidly absorbed when administered intramuscularly.citation needed It is hepatically metabolized primarily through direct glucuronidation to the inactive metabolite lorazepam-glucuronide, with CYP450 isoenzymes also reported to be involved. The glucuronide metabolite is eliminated by the kidneys, and lorazepam has no active metabolites. The elimination half-life is approximately 8 hours following oral administration,3 11 hours for sublingual dosing,3 and 14 hours when given parenterally.citation needed
Dangerous
Highest riskThese combinations are considered extremely harmful and should always be avoided. Reactions to these drugs taken in combination are highly unpredictable and have a potential to cause death.
Unsafe
AvoidThere is considerable risk of physical harm when taking these combinations, they should be avoided where possible.
Caution
Use cautionThese combinations are not usually physically harmful, but may produce undesirable effects, such as physical discomfort or overstimulation. Extreme use may cause physical health issues. Synergistic effects may be unpredictable. Care should be taken when choosing to use this combination.
Tolerance
Tolerance timelines are rules of thumb, not exact schedules, and vary widely between individuals and use patterns.
Full Tolerance
Sedative-hypnotic tolerance can appear after only a few days of uninterrupted use.
Cross Tolerance
Benzodiazepines
Baseline Reset
Tolerance typically returns to baseline within 7-14 days after cessation, though this may take significantly longer in proportion to the duration and intensity of long-term use.
Harm Potential
Addiction & Dependence
Psychological
Extremely HighLorazepam is described as extremely psychologically addictive with a very high dependence potential.citation needed Compulsive redosing is commonly reported, and the risk of abuse is increased in individuals with pre-existing substance dependence or psychiatric disorders.
Physical
Extremely HighPhysical dependence develops rapidly, with withdrawal symptoms possible after as little as one week of therapeutic use.citation needed Discontinuation can be life-threatening without proper medical tapering, with serious risk of seizures, hypertension, and death. As a potent short-acting benzodiazepine, lorazepam carries the highest risk of dependence within its class.
Toxicity
Central Nervous System
Long-term use may cause cognitive deficits, particularly affecting memory and new memory formation; these effects may persist for at least six months after discontinuation and may only be partially reversible, especially in elderly users.citation needed
Psychosis Risk
Psychosis is rare during therapeutic or recreational use but can occur as a withdrawal symptom following abrupt discontinuation after chronic use.citation needed Paradoxical reactions including hallucinations and delirium occur in less than 1% of the general population but are more common in recreational abusers, individuals with psychiatric disorders, children, and those on high-dose regimens.
Seizure Risk
Lorazepam has anticonvulsant properties and suppresses seizures during active use. However, abrupt withdrawal after regular use poses a significant seizure risk that can be life-threatening.2 Paradoxical worsening of seizures may rarely occur, particularly in individuals with epilepsy. Gradual tapering under medical supervision is essential to prevent withdrawal seizures.
History & Culture
Lorazepam was initially patented in 1963 and is considered one of the "classical" benzodiazepines alongside diazepam, clonazepam, oxazepam, nitrazepam, flurazepam, bromazepam, and clorazepate. The compound was developed by D.J. Richards, who served as president of research at Wyeth…
Legality
International
1961 Single Convention: not internationally scheduled.
1971 Convention on Psychotropic Substances: Schedule IV.
1988 Convention: not listed as a controlled precursor.
By Country
Prescription23
ArgentinaPrescription onlyLorazepam is a Lista IV psychotropic substance under Argentina's special-control medicines regime. Law No. 19.303 requires dispensing of Lista III and Lista IV psychotropic substances on a retained prescription, and ANMAT's registered-product listings identify lorazepam products as sold under retained prescription.
AustriaPrescription onlyLorazepam is expressly listed in Annex 1 to Austria's current Psychotropenverordnung, which defines the listed substances as psychotropic substances under the Suchtmittelgesetz. BASG identifies lorazepam as a psychotropic 1,4-benzodiazepine and states that benzodiazepines other than flunitrazepam are prescription-only medicines under § 10(4), with repeat dispensing prohibited. Flunitrazepam alone is identified by BASG as subject to the separate Suchtgiftrezept regime, so that special regime should not be attributed to lorazepam.
BrazilPrescription onlyPortaria SVS/MS No. 344/199814
Lorazepam is listed in Brazil's List B1 of psychotropic substances subject to prescription notification. Its dispensing is regulated under the controlled-medicines rules.
DenmarkPrescription onlyLorazepam is listed in List E of Denmark's Executive Order on Euphoriant Substances. The order permits possession only for persons and institutions receiving euphoriant substances under a prescription, requisition, or other specified authorization, and regulates their medical dispensing through authorized suppliers.
FrancePrescription onlyThe ANSM public medicines database records LORAZEPAM VIATRIS 1 mg as containing lorazepam and classifies the authorised medicine in Liste I. The current record states that its prescription is limited to 12 weeks. The medicine is therefore supplied under France's prescription-only regime for Liste I medicines.
GermanyPrescription onlyLorazepam is listed in Anlage III to Germany's Betäubungsmittelgesetz. Preparations containing no other Annex I–III substance and no more than 2.5 mg lorazepam per divided form are expressly excepted from that narcotics listing; lorazepam medicines remain prescription-only under the Arzneimittelverschreibungsverordnung. Preparations above the exception threshold are subject to the BtM prescription regime.
IrelandPrescription onlyMisuse of Drugs Regulations 201729
Lorazepam is listed in Schedule 4, Part 1 of the Misuse of Drugs Regulations. Its supply and possession are regulated as a controlled drug, with lawful medical supply through the prescription system.
MexicoPrescription onlyLey General de Salud30
Lorazepam is included in Mexico's official psychotropic-substances list. Its supply is subject to the General Health Law's prescription controls for psychotropic medicines.
NetherlandsPrescription onlyLorazepam is listed in Lijst II of the Dutch Opiumwet. The current Opiumwetbesluit places the substances on Lijst II, other than hashish, in its prescription annex and requires established pharmacists to dispense opium-law medicines only on a prescription. Netherlands-authorised medicines classified UR are available only on prescription.
PhilippinesPrescription onlyRepublic Act No. 9165 (Comprehensive Dangerous Drugs Act of 2002), sections 5, 18, 19 and 40; Schedule IV363738
The Dangerous Drugs Board-hosted text of RA 9165 lists lorazepam in the Act's Schedule IV. Section 5 makes sale, administration and dispensation of a dangerous drug unlawful unless authorised by law; section 40 prescribes the required three-copy prescription process for dangerous drugs, while sections 18 and 19 regulate prescriptions for such drugs. Lawful medical supply is prescription-only.
PolandPrescription onlyRegulation of the Minister of Health on the list of psychotropic substances, narcotic drugs and new psychoactive substances3940
Controlled under the psychotropic substances act as a Group IV-P substance, designated as having low potential for abuse. Legal for medical, scientific, and manufacturing purposes with appropriate authorization.
PortugalPrescription onlyLorazepam is included in INFARMED's list of active substances subject to mandatory prescription. INFARMED states that medicines subject to medical prescription may be dispensed by pharmacies only on presentation of a prescription issued by an authorized prescriber. Current INFARMED medicine records list authorised lorazepam products.
SingaporePrescription onlyLorazepam is listed in the Third Schedule to Singapore's Poisons Rules. Rule 15 provides that a poison in that Schedule may be sold only on and in accordance with a prescription given by a medical practitioner, dentist or veterinary surgeon. Lorazepam is therefore supplied through the prescription-only medicines regime.
SpainPrescription onlyThe Spanish Agency of Medicines and Medical Devices (AEMPS) records LORAZEPAM CINFA 1 mg COMPRIMIDOS EFG as an active marketed medicine subject to medical prescription and classified as a psychotropic medicine. The record identifies lorazepam as the active substance and marks the product as prescription-required.
TurkeyPrescription onlyTİTCK 2016/3 Kontrole Tabi Madde ve Müstahzarlara İlişkin Reçeteler Hakkında Genelge and the current TİTCK Yeşil Reçeteye Tabi İlaçlar listesi5354
The official TİTCK list places lorazepam-containing Ativan products in the green-prescription list, and TİTCK Genelge 2016/3 defines green prescriptions for psychotropic medicines and bars pharmacy supply without the required prescription procedure. These provisions establish prescription-only controlled dispensing. The dispensing provisions do not establish a broader criminal-law prohibition on possession or sale without a valid prescription.
UkrainePrescription onlyLorazepam is listed in Table III of the Ukrainian list of narcotic drugs, psychotropic substances and precursors approved by Cabinet of Ministers Resolution No. 770. The Law of Ukraine on narcotic drugs, psychotropic substances and precursors provides that citizens may acquire narcotic drugs or psychotropic substances included in Tables II and III only on a doctor's prescription. Lorazepam is therefore available only through the prescription-controlled medical system.
United KingdomPrescription onlyReferences
Source Pages
Citations
- Lorazepam: MedlinePlus Drug Information. U.S. National Library of Medicine (n.d.). https://medlineplus.gov/druginfo/meds/a682053.html1
- Ativan (lorazepam) tablet. DailyMed (13 January 2023). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=89057c93-8155-4040-acec-64e877bd2b4c1234
- Caillé G, Spénard J, Lacasse Y, & Brennan J. (1983). Pharmacokinetics of two lorazepam formulations, oral and sublingual, after multiple doses. Biopharmaceutics & Drug Disposition, 4(1), 31–42. https://doi.org/10.1002/bdd.251004010612
- World Health Organization model list of essential medicines: 21st list 2019. World Health Organization (2019). https://www.iccp-portal.org/sites/default/files/resources/WHO-MVP-EMP-IAU-2019.06-eng.pdf1
- Top 300 of 2023. ClinCalc (n.d.). https://clincalc.com/DrugStats/Top300Drugs.aspx1
- Lorazepam Drug Usage Statistics, United States, 2014 - 2023. ClinCalc (n.d.). https://clincalc.com/DrugStats/Drugs/Lorazepam1
- Law No. 19.303 and ANMAT special-control medicines register. argentina.gob.ar (n.d.). https://www.argentina.gob.ar/normativa/nacional/ley-19303-20966/actualizacion1
- Law No. 19.303 and ANMAT special-control medicines register. argentina.gob.ar (n.d.). https://www.argentina.gob.ar/sites/default/files/guia-uso-psicofarmacos-pna_2018.pdf1
- Law No. 19.303 and ANMAT special-control medicines register. anmat.gob.ar (n.d.). https://www.anmat.gob.ar/EspecMed/marzo/certificados_monofarmacos_10.asp1
- Psychotropenverordnung, Anhang 1 and § 10 Abs. 4. ris.bka.gv.at (n.d.). https://www.ris.bka.gv.at/GeltendeFassung.wxe?Abfrage=Bundesnormen&Gesetzesnummer=100110541
Further Reading
Article Status
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Recent changes8 human edits · latest
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19 August 2026
Lyrea · Updated the article
24 January 2026
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
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