Isoflurane and Ketamine interaction
Isoflurane and Ketamine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Ketamine (Ketalar) label · effective 2026-03-27
Benzodiazepines, Opioid Analgesics, or other CNS Depressants : Concomitant use may result in profound sedation, respiratory depression, coma, or death.
Benzodiazepines, Opioid Analgesics, or Other CNS Depressants Concomitant use 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 [see Drug Interactions ( 7.3 )] .
Closely monitor neurological status and respiratory parameters, including respiratory rate and pulse oximetry, when KETALR and opioid analgesics, benzodiazepines, or other CNS depressants are co-administered.
Benzodiazepines, Opioid Analgesics, Or Other CNS Depressants Concomitant use 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 [see Warnings and Precautions ( 5.9 )] .
From the Isoflurane (FORANE) label · effective 2024-12-09
Interactions with Desiccated Carbon Dioxide Absorbents FORANE, like some other inhalational anesthetics, can react with desiccated carbon dioxide (CO 2 ) absorbents to produce carbon monoxide, which may result in elevated levels of carboxyhemoglobin in some patients.
As with other halogenated anesthetic agents, FORANE may cause sensitivity hepatitis in patients who have been sensitized by previous exposure to halogenated anesthetics [see Contraindications (4) ] .
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.