Lorazepam

Lorazepam
Clinical data
Trade namesAtivan, others
Other nameso-Chloroxazepam
AHFS/Drugs.comMonograph
MedlinePlusa682053
License data
Pregnancy
category
  • AU: C
Dependence
liability
High
Addiction
liability
Moderate
Routes of
administration
By mouth, intramuscular, intravenous, transdermal
Drug classBenzodiazepine
ATC code
Legal status
Legal status
Pharmacokinetic data
BioavailabilityBy mouth: 85%
MetabolismLiver glucuronidation
Onset of action
  • IVTooltip Intravenous therapy: 1–5 minutes
  • IMTooltip Intramuscular injection: 15–30 minutes
  • POTooltip Oral administration: 20–30 minutes
Elimination half-life10–20 hours
Duration of action
  • IV/IM: 12–24 hours
  • PO: 6–8 hours
ExcretionKidney
Identifiers
  • (RS)-7-Chloro-5-(2-chlorophenyl)-3-hydroxy-1,3-dihydro-1,4-benzodiazepin-2-one
CAS Number
PubChem CID
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.011.534
Chemical and physical data
FormulaC15H10Cl2N2O2
Molar mass321.16 g·mol−1
3D model (JSmol)
  • O=C1Nc2ccc(Cl)cc2C(c2ccccc2Cl)=NC1O
  • InChI=1S/C15H10Cl2N2O2/c16-8-5-6-12-10(7-8)13(19-15(21)14(20)18-12)9-3-1-2-4-11(9)17/h1-7,15,21H,(H,18,20) Y
  • Key:DIWRORZWFLOCLC-UHFFFAOYSA-N Y
 NY (what is this?)  (verify)

Lorazepam, sold under the brand name Ativan among others, is a benzodiazepine medication. It is used to treat anxiety (including anxiety disorders), insomnia, severe agitation, active seizures including status epilepticus, alcohol withdrawal, and chemotherapy-induced nausea and vomiting. It is also used during surgery to interfere with memory formation, to sedate those who are being mechanically ventilated, and, along with other treatments, for acute coronary syndrome due to cocaine use. It can be given orally (by mouth), transdermally (on the skin via a topical gel or patch), intravenously (injection into a vein), or intramuscularly (injection into a muscle). When given by injection, onset of effects is between one and thirty minutes and effects last for up to a day.

Common side effects include weakness, sleepiness, ataxia, decreased alertness, decreased memory formation, low blood pressure, and a decreased effort to breathe. When given intravenously, the person should be closely monitored. Among those who are depressed, there may be an increased risk of suicide. With long-term use, larger doses may be required for the same effect. Physical dependence and psychological dependence may also occur. If stopped suddenly after long-term use, benzodiazepine withdrawal syndrome may occur. Older people more often develop adverse effects. In this age group, lorazepam is associated with falls and hip fractures. Due to these concerns, lorazepam use is generally recommended only for up to four weeks.

Lorazepam was initially patented in 1963 and went on sale in the United States in 1977. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication. In 2022, it was the 80th most commonly prescribed medication in the United States, with more than 8 million prescriptions.