Pharmacology of Anaesthetic Agents in Renal Failure

• The excretion of water soluble drugs and their active metabolites will be impaired.
• Induction agents are myocardial depressants and should be administered cautiously in patients with heart disease.
• Suxamethonium should be avoided if hyperkalemia is present
• Atracurium is the agent of choice as it undergoes spontaneous degradation (Hoffman) at body temperature. Vecuronium and mivacurium are safe to use in renal failure as only small percentages are excreted renally
• Morphine is metabolized in the liver to morphine-6-glucuronide which has about half the sedative effect of morphine with a markedly prolonged half life. Pethedine is partially metabolized to norpethidine which is less analgesic and has excitatory and convulsant properties. When available, morphine is preferable to pethidine. Fentanyl and benzodiazepine can be used in renal failure in reduced dosage.
• Non steroidal anti inflammatory agents (diclofenac, ketrolac) should be avoided as all decrease renal blood flow and may precipitate complete renal failure