Fluoxetine and Lorazepam interaction
Fluoxetine and Lorazepam: 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
LOREEV XR should not be used in such patients without adequate antidepressant therapy.
From the Fluoxetine (Prozac) label · effective 2026-01-08
Benzodiazepines: Diazepam – increased t½, alprazolam - further psychomotor performance decrement due to increased levels ( 7.7 )
Benzodiazepines — The half-life of concurrently administered diazepam may be prolonged in some patients [see Clinical Pharmacology ( 12.3 )] .
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.