Safety Considerations in the Use of Drug Combinations During General Anaesthesia

Abstract

The most commonly employed technique for providing general anaesthesia uses a balanced approach, where different drugs are used to reach specific desired endpoints. The variety of drugs used can result in a dozen or more different compounds being administered during a 'routine anaesthetic' procedure. Drug interactions are quite common and their clinical effects can be very significant. Clinically, general anaesthesia has 4 goals. These are: unconsciousness/amnesia; analgesia; muscle relaxation and maintenance of homeostasis. The anaesthesiologist tries to select only those drugs that permit a rapid onset of desirable operative conditions so that surgery can be performed properly and rapidly. Such drugs should also minimally disturb the patient's preoperative homeostatic maintenance, and maximise return to a desirable postanaesthetic functional state.

Concurrent medication and the neuromuscular junction

“…Anticholinesterase therapy is the mainstay of treatment for patients suffering from myasthenia gravis. The use of suxamethonium in these patients may have variable effects [110]. There is a documented resistance to onset of depolarizing block in patients who are maintained on their anticholinesterase therapy preoperatively [111].…”

Herbal monoterpene alcohols inhibit propofol metabolism and prolong anesthesia time

“…transSobrerol is another type of monoterpene alcohol that is widely used as a mucoregulating agent for the treatment of respiratory diseases with bronchial obstruction and mucus hypersecretion (Li et al, 2003;Watkins and Klaassen, 1983). Ventura et al has found that trans-sobrerol undergoes a hepatic P450 catalysed hydroxylation, in vivo in rat, dog, and human (De Oliveira et al, 1999;Pierce, 1999;Ransom and Mueller, 1997).…”

“…Propofol itself does not produce complete anesthesia because it lacks analgesic effects and has a short anesthetic effect after a single bolus administration (MacDougall et al, 2003;Ventura et al, 1983;Ransom and Mueller, 1997). Therefore, it is commonly used clinically in combination with opioids or inhaled anesthetics in order to produce a complete anesthesia state.…”