Prilocaine is a local anaesthetic agent with a half-life of two hours. The dose is 3-5mg/kg, giving a standard maximum total dose in adults of about 400 mg. With adrenaline, this is increased to 600 mg.
Prilocaine has a very low toxicity and so it is the drug of choice for Bier's block.
Metabolites of prilocaine can reduce haemoglobin to methaemoglobin which may turn the patient blue. However, if the maximum recommended dose of prilocaine is used (600 mg), only 5.3% of haemoglobin will be converted to methaemoglobin; a level at which cyanosis will be very slight.
Last reviewed 01/2018