Adult: 4 mg as a single dose, may be repeated once after 10-15 minutes if seizure continues or recurs. Child: 2 mg as a single dose. Elderly: Reduce to lower doses (half the usual adult dose or less).
Adult: 1-4 mg daily in divided doses for 2-4 weeks. Elderly: Reduce to lower doses (half the usual adult dose or less).
Oral Premedication in surgery
Adult: 2-3 mg given the night before the operation followed by 2-4 mg 1-2 hours before the procedure. Child: 5-13 years 0.5-2.5 mg at 0.05 mg/kg to the nearest 0.5 mg based on weight, not less than 1 hour before operation. Elderly: Reduce to lower doses (half the usual adult dose or less).
Oral Insomnia associated with anxiety
Adult: 1-2 mg at bedtime. Elderly: Reduce to lower doses (half the usual adult dose or less).
Parenteral Premedication in surgery
Adult: 0.05 mg/kg given 30-45 minutes before surgery via IV or 60-90 minutes before surgery via IM. Child: <12 years Not recommended. Elderly: Reduce to lower doses (half the usual adult dose or less).
Parenteral Acute anxiety
Adult: IV/IM: 0.025-0.03 mg/kg, may be repeated 6 hourly if necessary. Give IV inj at a rate of not more than 2 mg/minute. Child: <12 years Not recommended. Elderly: Reduce to lower doses (half the usual adult dose or less).
Special Patient Group
Debilitated patients: Reduce dose (half the usual dose or less), may adjust dose as needed and tolerated.
May require reduced doses.
Mild to moderate: May require reduced doses. Severe: Contraindicated.
May be taken with or without food.
IV inj: Dilute IV dose with an equal volume of compatible diluent (e.g. 5% dextrose, 0.9% NaCl, sterile water for inj). Infusion: Dilute to ≤1 mg/mL with compatible diluent.
Acute pulmonary insufficiency, respiratory depression, sleep apnoea, acute narrow-angle glaucoma, obsessional state, myasthenia gravis. Severe hepatic impairment. Pregnancy (planning a pregnancy, 1st or 3rd trimester).
Patients with respiratory disease (e.g. COPD), history of alcoholism or drug abuse, psychiatric or personality disorders; at risk of falls. Debilitated patients. Renal and mild to moderate hepatic impairment. Children and elderly. Pregnancy (2nd trimester) and lactation. Not indicated for primary treatment of psychotic illness or depressive disorders. Avoid abrupt withdrawal.
Significant: Physical and psychological dependence, withdrawal symptoms, anterograde amnesia, paradoxical reactions (including hyperactive or aggressive behaviour). Blood and lymphatic system disorders: Blood dyscrasia (e.g. agranulocytosis, leucopenia, thrombocytopenia, pancytopenia). General disorders and admin site conditions: Asthenia, fatigue, ataxia. Injury, poisoning and procedural complications: Injection site pain (IV/IM). Investigations: Elevated liver enzymes. Musculoskeletal and connective tissue disorders: Muscle weakness. Nervous system disorders: Drowsiness, sedation, dizziness, unsteadiness. Psychiatric disorders: Confusion, depression, hallucinations, stupor. Respiratory, thoracic and mediastinal disorders: Respiratory failure, apnoea. Skin and subcutaneous tissue disorders: Rash. Vascular disorders: Hypotension. Potentially Fatal: Respiratory depression, anaphylactoid reactions (e.g. angioedema in the tongue, glottis or larynx).
This drug may cause sedation, amnesia, impaired concentration, dizziness, impaired muscular function or blurred vision, if affected, do not drive or operate machinery.
Monitor respiratory and cardiovascular status, blood pressure, heart rate, symptoms of anxiety; CBC, LFT, LDH (prolonged use).
Symptoms: Drowsiness, mental confusion, paradoxical reactions, dysarthria and lethargy. Severe cases: Ataxia, hypotension, hypotonia, respiratory depression, cardiovascular depression, hypnotic state, coma, and very rarely, death. Management: Supportive and symptomatic treatment. Administer activated charcoal to reduce absorption. Induce vomiting or perform gastric lavage for recent ingestion. Maintain adequate airway and use assisted respiration as necessary. Hypotension may be controlled with norepinephrine. Flumazenil may be used as an adjunct for management of overdosage.
May enhance CNS depressant effect of NA oxybate, neuroleptics, antipsychotics, tranquilisers, antidepressants, hypnotics, anaesthetics, barbiturates (e.g. phenobarbital), sedative antihistamines. Enhanced sedative effect with HIV-protease inhibitors, cisapride, lofexidine, nabilone, disulfiram and muscle relaxants (e.g. tizanidine, baclofen). Increased serum concentration with anti-epileptic agents (e.g. valproate). Reduced clearance and enhanced actions with CYP450 inhibitors (e.g. cimetidine, isoniazid, erythromycin, omeprazole). Increased clearance and reduced effects with CYP450 inducers (e.g. rifampicin). Antagonistic effect with dopaminergics (e.g. levodopa). Reduced effects with theophylline or aminophylline. Scopolamine increases risk of sedation, hallucination and irrational behaviour. Antacids may delay absorption of lorazepam. Enhanced hypotensive effect with ACE inhibitors, angiotensin II receptor blockers, Ca channel blockers, diuretics, β-blockers. Potentially Fatal: Concomitant use with opioids increases the risks of sedation, respiratory depression, coma and death.
Enhanced sedative effects with alcohol. Reduced sedative and anxiolytic effects with caffeine. Increased plasma concentrations with grapefruit juice.
Description: Lorazepam is a short-acting benzodiazepine. It binds to stereospecific benzodiazepine receptors on the postsynaptic GABA neuron at several sites within the CNS (including the limbic system, reticular formation). Increased neuronal membrane permeability to chloride ions enhances the inhibitory effects of GABA thereby resulting to hyperpolarisation and stabilisation. Onset: Anticonvulsant: Within 10 minutes (IV); hypnosis: 20-30 minutes (IM); sedation: within 2-3 minutes (IV). Duration: Anaesthesia premedication: Approx 6-8 hours (IV, IM). Pharmacokinetics: Absorption: Readily absorbed from the gastrointestinal tract after oral administration; rapidly and completely absorbed after IM administration. Bioavailability: 90% (oral). Time to peak plasma concentrations: Approx 2 hours (oral); within 3 hours (IM). Distribution: Crosses placenta and blood-brain barrier; enters breastmilk. Volume of distribution: 1.3 L/kg. Plasma protein binding: Approx 85%. Metabolism: Metabolised in the liver, conjugated to lorazepam glucuronide (inactive metabolite). Excretion: Via urine (approx 88%; predominantly as inactive metabolites), faeces (approx 7%). Elimination half-life: Approx 12 hours (oral); approx 14 hours (IV); approx 13-18 hours (IM).
Tab: Store below 25°C. Oral solution/IV/IM inj: Store between 2-8°C. Protect from light.