Tacrolimus and Abacavir: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jun 30, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Tacrolimus
Abacavir
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
You've been prescribed tacrolimus (a medicine that calms your immune system, often after a transplant) along with abacavir (an HIV medicine). Both can be hard on the kidneys, and using them together may add up to put a little more stress on your kidneys.
The good news is this concern is theoretical, meaning it's based on how these drugs work rather than clear proof it happens often. Your care team knows how to watch for this. They can check your kidney function and your tacrolimus levels with blood tests and adjust doses if needed. Keep taking both as prescribed and let your pharmacist or doctor know if you notice less urination, swelling, or unusual tiredness.
Effect: Potential additive nephrotoxicity with concurrent tacrolimus and abacavir (an NRTI).
- Mechanism: Additive/overlapping nephrotoxic potential; no clinically significant CYP or transporter interaction implied here. Neither agent is a prodrug relevant to this effect.
- Direction/magnitude: Increased risk of renal impairment; magnitude not quantified.
- Onset: Unspecified.
- Evidence: Theoretical.
- Management: Monitor renal function (SCr, eGFR, urine output) and tacrolimus whole-blood trough concentrations. Doses of tacrolimus and/or the concomitant nephrotoxic agent may be individualized and adjusted by the care team. Tacrolimus is narrow-therapeutic-index, so small shifts warrant attention.
What happens
An increased risk of nephrotoxicity
Interaction Deep Dive
Taking tacrolimus alongside medications known to cause nephrotoxicity (for example, nucleoside reverse transcriptase inhibitors) can elevate the likelihood of nephrotoxicity. During periods when tacrolimus is administered together with other agents recognized as nephrotoxic, renal function and tacrolimus blood levels should be monitored, and the dosages of tacrolimus and/or the co-administered drugs should be adjusted throughout the time they are used together1.
Why it happens (mechanism)
Additive nephrotoxicity
How to manage this interaction
This interaction is generally manageable with routine follow-up.
- Keep taking both medications as prescribed unless your prescriber tells you otherwise.
- Your care team may monitor your kidney function and tacrolimus blood levels more closely with periodic blood tests.
- Doses of tacrolimus and/or the other medication may need to be adjusted and individualized by your team based on those results.
- Report signs of kidney trouble, such as reduced urination, swelling in your legs or feet, or unusual fatigue, to your pharmacist or prescriber.
- Ask before adding other kidney-affecting drugs, including some over-the-counter pain relievers (NSAIDs).
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Tacrolimus and Abacavir together?
Tacrolimus and abacavir can both stress the kidneys, so using them together may add up; your care team can manage this by checking your kidney function and tacrolimus levels and adjusting doses as needed. Keep taking both as prescribed and report any kidney warning signs. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Tacrolimus and Abacavir interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Tacrolimus and Abacavir interaction managed?
This interaction is generally manageable with routine follow-up. Keep taking both medications as prescribed unless your prescriber tells you otherwise. Your care team may monitor your kidney function and tacrolimus blood levels more closely with periodic blood tests. Doses of tacrolimus and/or the other medication may need to be adjusted and individualized by your team based on those results. Repo… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Tacrolimus or Abacavir need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: PROGRAF(R) oral capsules, oral granules for suspension, intravenous injection, tacrolimus oral capsules, oral granules for suspension, intravenous injection. Astellas Pharma US Inc (per FDA), Northbrook, IL, 2022. DailyMed
Keep reading about Tacrolimus
Keep reading about Abacavir
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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