Lorazepam and Promethazine interaction
Lorazepam and Promethazine: 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 Lorazepam (LOREEV XR) label · effective 2025-10-08
Caution patients receiving LOREEV XR against operating machinery or driving a motor vehicle as well to avoid the concomitant use of alcohol and other CNS depressant drugs during treatment ( 5.4 , 7 )
Use of benzodiazepines, including LOREEV XR, both used alone and in combination with other CNS depressants, may lead to potentially fatal respiratory depression.
Alcohol should be avoided and other CNS depressant drugs used with caution during treatment with LOREEV XR [see Drug Interactions ( 7 )] .
Use caution if LOREEV XR is co-administered with other CNS-depressants [see Warnings and Precautions (5.4)] .
From the Promethazine (PROMETHAZINE HYDROCHLORIDE) label · effective 2026-04-16
The impairment may be amplified by concomitant use of other central-nervous-system depressants such as alcohol, sedatives/hypnotics (including barbiturates), narcotics, narcotic analgesics, general anesthetics, tricyclic antidepressants, and tranquilizers; therefore such agents should either be eliminated or given in reduced dosage in the presence of promethazine…
Drug Interactions CNS Depressants Promethazine Syrup may increase, prolong, or intensify the sedative action of other central-nervous-system depressants, such as alcohol, sedatives/hypnotics (including barbiturates), narcotics, narcotic analgesics, general anesthetics, tricyclic antidepressants, and tranquilizers; therefore, such agents should be avoided or administered…
CNS Depressants Promethazine Syrup may increase, prolong, or intensify the sedative action of other central-nervous-system depressants, such as alcohol, sedatives/hypnotics (including barbiturates), narcotics, narcotic analgesics, general anesthetics, tricyclic antidepressants, and tranquilizers; therefore, such agents should be avoided or administered in reduced…
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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.