Lorazepam and Thioridazine interaction
Lorazepam and Thioridazine: 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 )
Prescribe the lowest effective dosage; avoid or minimize concomitant use of CNS depressants and other substances associated with abuse, misuse, and addiction (e.g., opioid analgesics, stimulants); and advise patients on the proper disposal of unused drug.
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 )] .
CNS depressants: Additive CNS depressant effects (7)
From the Thioridazine (Thioridazine Hydrochloride) label · effective 2026-03-02
Attention should be paid to the fact that phenothiazines are capable of potentiating central nervous system depressants (e.g., anesthetics, opiates, alcohol, etc.) as well as atropine and phosphorus insecticides.
Central Nervous System Depressants As in the case of other phenothiazines, thioridazine is capable of potentiating central nervous system depressants (e.g., alcohol, anesthetics, barbiturates, narcotics, opiates, other psychoactive drugs, etc.) as well as atropine and phosphorus insecticides.
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.