Butalbital, acetaminophen, caffeine, and codeine and Nefazodone interaction
Butalbital, acetaminophen, caffeine, and codeine and Nefazodone: 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 Butalbital, acetaminophen, caffeine, and codeine (Butalbital, Acetaminophen, Caffeine and Codeine Phosphate) label · effective 2026-01-02
Interactions with Drugs Affecting Cytochrome P450 Isoenzymes The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex.
Use of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with Butalbital, Acetaminophen, Caffeine, and Codeine Phosphate Capsules requires careful consideration of the effects on codeine, and the active metabolite, morphine [see Warnings and Precautions ( 5.7 )] .
• The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex.
• Serotonergic Drugs: Concomitant use may result in serotonin syndrome.
Risks of Interactions with Drugs Affecting Cytochrome P450 Isoenzymes The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex.
From the Nefazodone (Nefazodone Hydrochloride) label · effective 2025-07-31
FEV 1 measurements taken when theophylline and nefazodone were coadministered did not differ from baseline dosage (i.e., when theophylline was administered alone).
Theophylline When nefazodone (200 mg BID) was given to patients being treated with theophylline (600 to 1200 mg/day) for chronic obstructive pulmonary disease, there was no change in the steady-state pharmacokinetics of either nefazodone or theophylline.
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.