Lecture Notes: Lorazepam (Ativan)
Introduction
- Presenter: Ryan from rpnt.ca
- Topic: Lorazepam, also known as Ativan
- Belongs to benzodiazepine drug class (benzos)
Mechanism of Action
- Enhances the effect of gamma-aminobutyric acid (GABA)
- GABA: Main inhibitory neurotransmitter in the central nervous system (CNS)
Neuron Function
- Neurons transfer information via electrical signals (action potentials)
- Neurotransmitters influence action potentials
- Excitatory: Promote action potentials
- Inhibitory: Inhibit action potentials (e.g., GABA)
- GABA reduces neuron excitability, slowing information transfer
Benzodiazepines and GABA
- Benzodiazepines enhance GABA effects
- Resulting effects: Sedation, drowsiness, muscle relaxation, decreased anxiety
Uses of Lorazepam
- Treatment of anxiety symptoms
- Anxiety-associated insomnia
- Pre-operative anesthetic
- Status epilepticus: Severe form of seizures
Off-label Uses
- Seizure prophylaxis
- Alcohol withdrawal syndrome
- Muscle spasms
Side Effects
- Related to CNS depression
- Common: Sedation, dizziness, weakness, unsteadiness
- Less common: Hypotension, blurred vision, suicidal ideations, tachycardia, respiratory depression
Contraindications and Precautions
- Contraindicated in patients with hypersensitivity to benzodiazepines
- Avoid in narrow-angle glaucoma
- Exercise caution in:
- History of addiction
- Suicidal ideations
- Untreated depression
- Respiratory diseases (COPD, sleep apnea)
- Impaired renal/hepatic function
- Elderly (doses may need adjustment)
- Children under 12 (safety not established)
Interactions and Administration
- Interactions with CNS depressants (opioids, alcohol) can increase sedation, respiratory depression
- Ensure support for ambulation and daily activities when starting treatment
Overdose Treatment
- Benzodiazepine antagonist: Flumazenil may be used
- Flumazenil blocks/inhibits GABA receptors
Discontinuation
- Do not abruptly stop lorazepam; gradually taper dose per provider's instructions
For further questions or help, visit rpnt.ca.