Adult: For cases associated with tetanus, status epilepticus, or poisoning: 5-10 mL via deep inj into the buttocks. Do not give >5 mL/inj site. Child: For cases associated with status epilepticus: 0.1-0.15 mL/kg 4-8 hourly via deep inj into the buttocks. Do not give >5 mL/inj site.
Intramuscular Alcohol withdrawal syndrome
Adult: For the management of acute agitation or delirium tremens: 5 mL 4-6 hourly for 24 hours (max: 30 mL on day 1); then 6 hourly thereafter (max: 20 mL/day). Doses are to be given via deep inj into the buttocks. Do not give >5 mL/inj site.
Intramuscular Hypnotic
Adult: 10 mL via deep inj into the buttocks. Do not give >5 mL/inj site. Child: 0.3 mL/kg daily via deep inj into the buttocks. Do not give >5 mL/inj site.
Intramuscular Sedation
Adult: 5 mL via deep inj into the buttocks. Do not give >5 mL/inj site. Child: 0.15 mL/kg daily via deep inj into the buttocks. Do not give >5 mL/inj site.
Hepatic Impairment
Severe: Contraindicated
Incompatibility
Incompatible with plastic or rubber.
Contraindications
Bronchopulmonary disease. Severe hepatic impairment. Pregnancy. Concomitant administration with other CNS depressants.
Special Precautions
Patient with CV disease, respiratory disease (e.g. asthma); history of drug abuse or acute alcoholism. Not for use as obstetric anaesthesia. For use as an alternative agent when conventional therapy is unavailable, ineffective, or inappropriate. For short-term use only (as hypnotic or sedative). Avoid abrupt withdrawal. Avoid injecting near nerve trunks; may cause severe and permanent nerve damage. Use glass syringes for administration. Mild to moderate hepatic impairment. Children. Lactation.
Adverse Reactions
Significant: CNS depression, metabolic acidosis. If prolonged use: Nephrosis, toxic hepatitis, tolerance, psychological and physical dependence. General disorders and administration site conditions: Inj site reaction (e.g. extreme pain, sterile skin abscess, skin sloughing, fat necrosis, muscular irritation, nerve damage [including permanent damage]). Musculoskeletal and connective tissue disorders: Muscle cramps. Nervous system disorders: Dizziness, tremor. Skin and subcutaneous tissue disorders: Rash, diaphoresis. Potentially Fatal: Corrosive poisoning (administration of decomposed solution).
Patient Counseling Information
Avoid contact with eyes, skin and clothing. This drug may cause drowsiness, if affected, do not drive or operate machinery.
Monitoring Parameters
Evaluate pregnancy status before initiating therapy.
Overdosage
Symptoms: Short and troubled, rapid breathing; cloudy urine, reduced urination, slow heartbeat, general weakness, odour of the drug on the breath, severe hypotension, metabolic acidosis (with increased anion gap), respiratory depression, pulmonary oedema, impaired renal function (e.g. azotaemia, albuminuria, oliguria), nephrosis, fatty changes in the kidneys or liver, toxic hepatitis, cardiac failure and coma. Management: Symptomatic and supportive treatment. Maintain adequate airway, control respiration and administer oxygen to re-establish adequate respiratory exchange. Administer IV Na bicarbonate or Na lactate to correct metabolic acidosis. Maintain body temperature and support circulation with IV fluids or vasopressors if needed.
Drug Interactions
May potentiate CNS depression with other CNS depressants (e.g. barbiturates); avoid concomitant use.
Food Interaction
May potentiate CNS depression with alcohol.
Action
Description: Mechanism of Action: Paraldehyde is a cyclic trimer of acetaldehyde with unknown mechanism of action. It is believed to cause CNS depression, including the ascending reticular activating system leading to hypnosis or sedation and anticonvulsant activity (in sub-hypnotic doses). In sub-anaesthetic doses, it has no analgesic activity and may produce delirium or excitement in the presence of pain. Onset: Sedation or hypnosis: 5-15 minutes (IM). Duration: 8 hours. Pharmacokinetics: Absorption: Rapidly absorbed from the injection site. Time to peak plasma concentration: within 20-60 minutes. Distribution: Diffuses into the CSF. Crosses the placenta. Metabolism: Metabolised (approx 80-90% of the dose) in the liver into acetaldehyde, then oxidised by aldehyde dehydrogenase into acetic acid and further metabolised into CO2 and water. Excretion: Mainly via the lungs (as unchanged drug); urine (small amounts, as unchanged drug). Elimination half-life: Approx 3.5-9.5 hours.
Chemical Structure
Paraldehyde Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 31264, Paraldehyde. https://pubchem.ncbi.nlm.nih.gov/compound/Paraldehyde. Accessed July 27, 2021.
Storage
Store below 25°C. Do not refrigerate. Protect from light. May crystallise at approx 12°C; warm gently if crystallisation occurs. Use immediately upon opening; do not use if the solution has a brownish colour or has an odour of acetic acid. This is a hazardous drug. Follow applicable procedures for receiving, handling, administration, and disposal.