Suprane Drug Interactions

No clinically significant adverse interactions with commonly used preanesthetic drugs, or drugs used during anesthesia (muscle relaxants, intravenous agents, and local anesthetic agents) were reported in clinical trials. The effect of SUPRANE on the disposition of other drugs has not been determined. Similar to isoflurane, SUPRANE does not predispose to premature ventricular arrhythmias in the presence of exogenously infused epinephrine in swine.
Benzodiazepines and Opioids (MAC Reduction): Benzodiazepines and opioids decrease the amount of desflurane (MAC) needed to produce anesthesia. This effect is shown in Table 10 for intravenous midazolam (25-50 μg/kg) and intravenous fentanyl (3-6 μg/kg) in patients of two different age groups. (See Table 10.)

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Neuromuscular Blocking Agents: Anesthetic concentrations of desflurane at equilibrium (administered for 15 or more minutes before testing) reduced the ED₉₅ of succinylcholine by approximately 30% and that of atracurium and pancuronium by approximately 50% compared to N₂O/opioid anesthesia (see Table 11). The effect of desflurane on duration of nondepolarizing neuromuscular blockade has not been studied. (See Table 11.)

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Dosage reduction of neuromuscular blocking agents during induction of anesthesia may result in delayed onset of conditions suitable for endotracheal intubation or inadequate muscle relaxation, because potentiation of neuromuscular blocking agents requires equilibration of muscle with the delivered partial pressure of SUPRANE.
Among nondepolarizing drugs, pancuronium, atracurium, and vecuronium interactions have been studied. In the absence of specific guidelines: 1. For endotracheal intubation, do not reduce the dose of nondepolarizing muscle relaxants or succinylcholine.
2. During maintenance of anesthesia, the dose of nondepolarizing muscle relaxants is likely to be reduced compared to that during N₂O/opioid anesthesia. Administration of supplemental doses of muscle relaxants should be guided by the response to nerve stimulation.
Concomitant use with N₂O: Concomitant administration of N₂O reduces the MAC of SUPRANE [see Table 8 in Dosage & Administration].