magnesium chloride hexahydrate + potassium chloride + procaine hydrochloride: clinical use

Prescribing considerations

• Restricted to use during cardiac surgery for coronary-artery infusion during cardiopulmonary bypass.
• The concentrate must be diluted with the specified infusion fluid immediately before use.
• Excessive exposure may present with apnoea, circulatory depression or seizures and requires supportive management.

Contraindications and cautions

• Hypersensitivity to procaine.
• Check for allergy to the active substances or excipients before administration.

Monitoring

• No product-specific monitoring schedule is stated; administration occurs within full cardiac-surgical and anaesthetic monitoring.
• Observe myocardial electrical activity, circulation and recovery from cardioplegia, and remain alert for hypersensitivity or toxicity.

Clinical pharmacology

Potassium produces marked effects on myocardial electrical activity; magnesium prolongs cardiac conduction; and procaine reduces myocardial excitability, conduction and contractile force. Procaine is rapidly metabolised, with only a small proportion excreted unchanged in urine.

Formulation and product differences

• The selected product is a clear, colourless sterile aqueous concentrate in glass ampoules and is not ready for direct administration.
• Excipients include disodium edetate, sodium hydroxide and water for injections.