Drug interactions
Glycerol phenylbutyrate + Tacrolimus
Severity: Moderate
Glycerol phenylbutyrate and Tacrolimus: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Glycerol phenylbutyrate may weakly induce CYP3A4, which could lower tacrolimus concentrations. Reduced exposure may lead to loss of immunosuppression and a risk of graft rejection.
What this interaction means in plain words
Glycerol phenylbutyrate and Tacrolimus can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Glycerol phenylbutyrate belongs to Miscellaneous; Tacrolimus belongs to Miscellaneous.
Why it happens
Weak induction of CYP3A4 increases tacrolimus metabolism.
What to do
Monitor tacrolimus trough levels after starting or stopping glycerol phenylbutyrate. Increase the tacrolimus dose if levels fall below target.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Tacrolimus
- Adenovirus types 4 and 7 live + Tacrolimus Contraindicated
- Bcg vaccine live + Tacrolimus Contraindicated
- Cidofovir + Tacrolimus Contraindicated
- Cyclosporin + Tacrolimus Contraindicated
- Influenza virus vaccine quadrivalent intranasal + Tacrolimus Contraindicated
- Measles mumps and rubella vaccine live + Tacrolimus Contraindicated
Other interactions of Glycerol phenylbutyrate
- Dexamethasone + Glycerol phenylbutyrate Major
- Glycerol phenylbutyrate + Sodium valproate Major
- Glycerol phenylbutyrate + Valproic acid Major
- Cyclosporin + Glycerol phenylbutyrate Moderate
- Dexamethasone-neomycin-polymyxin + Glycerol phenylbutyrate Moderate
- Dexamethasone-tobramycin + Glycerol phenylbutyrate Moderate
Frequently asked questions
Can I take Glycerol phenylbutyrate with Tacrolimus?
MediHelp rates the interaction as moderate. Glycerol phenylbutyrate and Tacrolimus can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Glycerol phenylbutyrate may weakly induce CYP3A4, which could lower tacrolimus concentrations. Reduced exposure may lead to loss of immunosuppression and a risk of graft rejection.
How serious is the interaction between Glycerol phenylbutyrate and Tacrolimus?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor tacrolimus trough levels after starting or stopping glycerol phenylbutyrate. Increase the tacrolimus dose if levels fall below target.
What other medicines interact with Tacrolimus?
MediHelp also lists interactions of Tacrolimus with, for example, Adenovirus types 4 and 7 live, Bcg vaccine live, Cidofovir. The full list is on the Tacrolimus page.
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