Anaesthesia drug combinations

E.S. Ransom, and R.A. Mueller, Safety consideration in the use of drug combinations during general anaesthesia. Drug Safety 16 88-103, 1997. 

In a double-blind study in 11 healthy subjects there were several instances when alcohol 0.25 to 5 g/kg (equivalent to 1 to 3 drinks) enhanced the effects of nitrous oxide 30% in oxygen, inhaled for 35 minutes. Some effects were seen with the drug combination, which were not seen with either drug alone these included subjective effects and delayed free recall. For mention of the effect of alcohol following anaesthesia, see Anaesthetics, general -I- Alcohol , p.92. 

The effects of fentanyl and droperidol with fentanyl in depressing respiration were studied in 29 subjects undergoing nitrous oxide anaesthesia. The combination of the drugs used was the proprietary preparation Innovar containing fentanyl 0.05 mg/ml and droperidol 2.5 mg/ml. In the study patients received fentanyl, alone or as Tn-novar , 1.5 pg/kg by intramuscular injections... 

General anaesthesia can encompass several different end points, the most critical of which can be defined as unconsciousness. A loss of sensation including that of any painful stimulus, and muscle relaxation are also desirable endpoints of general anaesthesia. Modern-day anaesthesia is accomplished using a balanced combination of different drugs to confer these different endpoints. 

Nitrous oxide is used for the maintenance of anaesthesia as part of a combination of drugs because, owing to its lack of potency, it cannot be used... 

Combining midazolam and alfentanil or fentanyl for the induction of anaesthesia reduces the dose required of both the benzodiazepine and the opioid, when compared with either drug alone.The interaction is synergistic. ... 

A number of sedative drugs are used in veterinary medicine, including drugs used prior to anaesthesia, for relieving stress, or in combination with analgesics. The major groups are discussed below. 

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