ketamine hydrochloride: clinical use

Prescribing considerations

• Restrict administration to appropriately equipped settings under experienced medical supervision, except in emergencies.
• Ensure airway-management and resuscitation equipment is immediately available.
• Assess cardiovascular, respiratory, liver, neurological and psychiatric conditions, plus seizure and substance-use history.
• Use careful justification for repeated or extended exposure because of hepatobiliary, urinary-tract, tolerance and dependence risks.

Contraindications and cautions

• Hypersensitivity to ketamine hydrochloride or a formulation excipient
• Any condition in which increased blood pressure would present a serious hazard
• Eclampsia or pre-eclampsia
• Severe coronary or myocardial disease
• Recent cerebrovascular accident or cerebral trauma

Monitoring

• Airway patency, respiratory rate and oxygenation
• Blood pressure, heart rate and cardiac function where indicated
• Depth of anaesthesia, recovery and emergence reactions
• Liver function and urinary symptoms with prolonged or repeated exposure
• Tolerance, dependence or misuse

Clinical pharmacology

Racemic ketamine produces dissociative anaesthesia principally through NMDA-receptor antagonism. It is rapidly distributed, metabolised in the liver primarily through CYP3A4 to norketamine, and excreted mainly as renal metabolites. Sympathomimetic effects typically increase heart rate, blood pressure and myocardial oxygen demand.

Formulation and product differences

• Both selected products are clear parenteral solutions for injection or infusion.
• The hameln formulation contains benzethonium chloride as a preservative.
• The Flynn formulation contains water for injection with sodium hydroxide and hydrochloric acid and is supplied for single use.
• Check product-specific compatibility, dilution, storage and disposal instructions.

Injection

Route: Parenteral

Strengths: 10 mg/mL, 50 mg/mL