Terbinafine and Cyclosporine Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Cyclosporine Injection
Terbinafine
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.
What happens
Reduced cycloSPORINE exposure and a reduced therapeutic response to cycloSPORINE
Interaction Deep Dive
Concomitant use of cycloSPORINE and terbinafine may decrease cycloSPORINE levels. Adjust cycloSPORINE dosage to achieve the desired cycloSPORINE concentrations when these drugs are administered concomitantly12. Terbinafine has been found to increase the clearance of cycloSPORINE by 15% 5. The clinical impact of this effect is not clear; however, decreased cycloSPORINE serum levels and an increased risk of organ rejection are possible. Terbinafine was used successfully with cycloSPORINE in four renal transplant patients. Out of the four cases, an increase in cycloSPORINE dose was necessary in only one patient 4.
Why it happens (mechanism)
Increased metabolic degradation of cycloSPORINE
Literature reports
3 reports — tap to read
a) Eleven stabilized transplant patients immunosuppressed with cycloSPORINE and with culture-proven dermatophyte toe nail infection were followed. Patients were given terbinafine 250 mg daily for twelve weeks. No changes were made or had been made in the cycloSPORINE doses in the three months preceding terbinafine therapy. Blood samples were drawn before terbinafine treatment and at 4, 8, and 12 weeks. Results showed a statistically significant decrease in the mean cycloSPORINE blood trough level at four weeks, but stable levels thereafter. No significant increase in maximum concentration (Cmax), time of maximum concentration (Tmax), area under the concentration time curve from 0 to 8 hours (AUC 0-8), or elimination half-time (T1/2) was found. These results suggest that terbinafine possibly induces metabolic degradation of cycloSPORINE but the enzyme induction is almost negligible and of little clinical significance. The authors concluded that terbinafine therapy is safe in cycloSPORINE-treated patients with dermatophyte nail infections but recommended that cycloSPORINE levels be controlled during treatment 3.
b) Four cases in which terbinafine was used concurrently with cycloSPORINE in renal transplant patients were reported. In all four cases, terbinafine 250 mg daily lowered trough cycloSPORINE levels. However, in three of the four patients, the decrease in cycloSPORINE level was small and no cycloSPORINE dosage increase was necessary. In the fourth patient, stepwise increases in cycloSPORINE dosage from 3.6 mg per kg per day to 6.5 mg per kg per day were necessary. The authors concluded that terbinafine was a safe and effective drug for patients receiving cycloSPORINE, but stressed that monitoring of cycloSPORINE levels was necessary for patients with drug levels at the lower end of the therapeutic range 4.
c) Terbinafine has been found to increase the clearance of cycloSPORINE by 15% 5.
Common questions
Can I take Terbinafine and Cyclosporine Injection together?
Reduced cycloSPORINE exposure and a reduced therapeutic response to cycloSPORINE Always confirm with your pharmacist or prescriber before making any change.
How serious is the Terbinafine and Cyclosporine Injection interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Terbinafine or Cyclosporine Injection 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 (5)
- Product Information: NEORAL(R) oral soft gelatin capsules oral solution, cyclosporine modified oral soft gelatin capsules oral solution. Novartis Pharmaceuticals Corporation (per FDA), East Hanover, NJ, 2023. DailyMed
- Product Information: SANDIMMUNE(R) oral capsules, oral solution, intravenous injection, cyclosporine oral capsules, oral solution, intravenous injection. Novartis Pharmaceuticals Corporation (per FDA), East Hanover, NJ, 2023. DailyMed
- Jensen P, Lehne G, Fauchald P, et al: Effect of oral terbinafine treatment on cyclosporin pharmacokinetics in organ transplant recipients with dermatophyte nail infection. Acta Derm Venereol 1996; 76:280-281. DOI
- Lo ACY, Lui S, Lo W, et al: The interaction of terbinafine and cyclosporine A in renal transplant patients. Br J Clin Pharmacol 1997; 43:340-341.
- Product Information: LAMISIL(R) oral tablets, terbinafine HCl oral tablets. Novartis Pharmaceuticals Corporation (per manufacturer), East Hanover, NJ, 2016. DailyMed
Keep reading about Cyclosporine Injection
Keep reading about Terbinafine
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