Ketamine may also be given by intramuscular injection to induce
anaesthesia. With a dose of 6–8 mg/kg of body weight,
induction occurs within a few minutes, followed by 10–15
minutes of surgical anaesthesia. At 8 mg/kg of body weight,
ketamine produces a marked increase in salivary secretions.
If you use intramuscular ketamine, give atropine (which can
be mixed with the ketamine) to prevent excessive salivation.
Further doses of ketamine can be given intramuscularly or intravenously,
as required. Intramuscular doses last longer and wear off more
slowly. If ketamine is used as the sole anaesthetic agent,
patients sometimes complain afterwards of vivid dreams and
hallucinations; giving diazepam either before or at the end
of anaesthesia can reduce these. They do not occur if ketamine
is used only for induction and is followed by a conventional