Drug Interactions between ketamine / midazolam / ondansetron and ropivacaine / sufentanil

MONITOR CLOSELY: Coadministration of ketamine with other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. In addition, opioid analgesics, barbiturates, and benzodiazepines may prolong the time to complete recovery from anesthesia.

MANAGEMENT: During concomitant use of ketamine with other CNS depressants, including alcohol, close monitoring of neurologic status and respiratory parameters, including respiratory rate and pulse oximetry, is recommended. Dosage adjustments should be considered according to the patient's clinical situation. Ambulatory patients should be counseled to avoid hazardous activities requiring mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

Switch to consumer interaction data

MONITOR CLOSELY: Coadministration of ketamine with opioid analgesics, benzodiazepines, or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Concomitant use of ketamine with other CNS depressants can potentiate CNS depression and/or increase the risk of developing respiratory depression. In addition, opioid analgesics, barbiturates, and benzodiazepines may prolong the time to complete recovery from anesthesia.

MANAGEMENT: During concomitant use of ketamine with opioid analgesics, benzodiazepines, or other central nervous system (CNS) depressants, including alcohol, close monitoring of neurologic status and respiratory parameters, including respiratory rate and pulse oximetry, is recommended. Dosage adjustments should be considered according to the patient's clinical situation. Ambulatory patients should be counseled to avoid hazardous activities requiring mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

Switch to consumer interaction data

GENERALLY AVOID: Concomitant use of opioids with benzodiazepines may result in profound sedation, respiratory depression, coma, and death. The use of benzodiazepines with sufentanil during induction has been reported to decrease mean arterial pressure and systemic vascular resistance. The mechanism appears to be an indirect effect on the autonomic nervous system.

MANAGEMENT: The use of opioids in conjunction with benzodiazepines or other CNS depressants should generally be avoided unless alternative treatment options are inadequate. If coadministration is necessary, the dosage and duration of each drug should be limited to the minimum required to achieve desired clinical effect. Patients receiving sufentanil with benzodiazepines should be monitored closely for signs and symptoms of respiratory depression, altered hemodynamics, and hypotension.

Switch to consumer interaction data

MONITOR CLOSELY: Concomitant use of 5-HT3 receptor antagonists with agents that possess or enhance serotonergic activity such as selective serotonin reuptake inhibitors (SSRIs), selective serotonin-norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants (TCAs), 5-HT1 receptor agonists (triptans), ergot alkaloids, phenylpiperidine opioids, bupropion, dextromethorphan, linezolid, lithium, St. John's wort, tramadol, and tryptophan may potentiate the risk of serotonin syndrome, which is a rare but serious and potentially fatal condition thought to result from hyperstimulation of brainstem 5-HT1A and 2A receptors. According to the manufacturers, development of serotonin syndrome has been reported with 5-HT3 receptor antagonists, primarily during concomitant use of serotonergic drugs but also in overdose. Some of the reported cases were fatal. Symptoms of the serotonin syndrome may include mental status changes such as irritability, altered consciousness, confusion, hallucination, and coma; autonomic dysfunction such as tachycardia, hyperthermia, diaphoresis, shivering, blood pressure lability, and mydriasis; neuromuscular abnormalities such as hyperreflexia, myoclonus, tremor, rigidity, and ataxia; and gastrointestinal symptoms such as abdominal cramping, nausea, vomiting, and diarrhea.

MANAGEMENT: Caution is advised if 5-HT3 receptor antagonists are prescribed with other agents that affect the serotonergic neurotransmitter system. Patients should be closely monitored for symptoms of the serotonin syndrome during treatment. Particular caution is warranted when initiating or increasing the dosages of these agents. The potential risk for serotonin syndrome should be considered even when administering serotonergic agents sequentially, as some agents may demonstrate a prolonged elimination half-life. For example, a 5-week washout period is typically recommended following use of fluoxetine and 2 weeks following use of MAOIs before administering another serotonergic agent. If serotonin syndrome develops or is suspected during the course of therapy, all serotonergic agents should be discontinued immediately and supportive care rendered as necessary. Moderately ill patients may also benefit from the administration of a serotonin antagonist (e.g., cyproheptadine, chlorpromazine). Severe cases should be managed under consultation with a toxicologist and may require sedation, neuromuscular paralysis, intubation, and mechanical ventilation in addition to the other measures.

Switch to consumer interaction data

MONITOR: The risk of neurotoxicity may be increased when local anesthetics are used together with intraspinal ketamine. Animal and cell studies have shown that the combined neurotoxicity of lidocaine and ketamine are additive.

MANAGEMENT: Caution is advised during concomitant use of local anesthetics with intraspinal ketamine.

Switch to consumer interaction data

MONITOR: The concomitant use of local anesthetics and benzodiazepines may have additive CNS-depressant effects. Both types of drugs are CNS depressants. Benzodiazepines administered at the same time raise the threshold for seizures, which is a sign of toxicity for local anesthetics. The data available from manufacturers in different countries is conflicting. Moreover, benzodiazepines (such as diazepam) may be used together with local anesthetics for emergencies in cases of overdosage, while considering the depressive effects benzodiazepines have on respiration and circulation.

MANAGEMENT: Caution is advised during concurrent use. Patients should be monitored for potentially excessive or prolonged CNS depression and other CNS adverse effects. Dosage adjustments may be required. The higher threshold for seizures should be kept in mind when patients receiving these drugs simultaneously are monitored for local anesthetic toxicity.

Switch to consumer interaction data