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Cyclosporine (Systemic)

Prescription

Calcineurin Inhibitor / Immunosuppressant

Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team

Species

Dog, Cat

Brands

3 available

Interactions

15 documented

Formulations

Mechanism of action

Binds cyclophilin forming a complex that inhibits calcineurin phosphatase, blocking IL-2 transcription and T-lymphocyte activation. Suppresses cell-mediated immunity without significant myelosuppression.

At a glance

Class

Calcineurin Inhibitor / Immunosuppressant

Schedule

Prescription

Storage

Store at room temperature; oral solution use within 2 months after opening; do not refrigerate

Dosing

🐕

Dog

FDA-approved (Atopica) for canine atopic dermatitis

Dose

5–10 mg/kg

Route

Frequency

q24h (dermatitis) or q12h (immune-mediated)

🐈

Cat

FDA-approved for feline allergic dermatitis

Dose

7 mg/kg

Route

Frequency

q24h

Educational reference only

This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Formulations

💊

Other — 2

Strength

—

Strength

—

Storage

Store at room temperature; oral solution use within 2 months after opening; do not refrigerate

Safety

Monitoring parameters

GI tolerance initiallyRenal function q6 monthsCBC q6 monthsTrough levels for immune-mediated diseaseSkin response at 4–6 weeks

Educational reference only

Interactions

Major — 5

Phenobarbital

major

Phenobarbital potently induces CYP3A4, dramatically reducing cyclosporine levels (50-75% decrease), potentially causing therapeutic failure.

Management: Increase cyclosporine dose or consider alternative anticonvulsant. Monitor cyclosporine trough levels closely.

Rifampicin

major

Rifampicin is the most potent known CYP3A4 inducer, reducing cyclosporine plasma levels by 50-90% within days, causing therapeutic failure and transplant rejection or immune-mediated disease flare.

Management: Avoid combination. If essential, increase cyclosporine dose 2-5 fold and monitor trough levels closely. Consider alternative antibiotic.

Clarithromycin

major

Clarithromycin potently inhibits CYP3A4, increasing cyclosporine levels 2-3 fold. More potent CYP inhibitor than azithromycin.

Management: Avoid if possible. If needed, reduce cyclosporine dose by 50% and monitor trough levels closely.

Posaconazole

major

Posaconazole potently inhibits CYP3A4, increasing cyclosporine levels 2-4 fold.

Management: Reduce cyclosporine dose by 50-75%. Monitor trough levels closely.

Voriconazole

major

Voriconazole potently inhibits CYP3A4, increasing cyclosporine levels 2-3 fold.

Management: Reduce cyclosporine dose by 50%. Monitor trough levels closely.

Moderate — 8

Ketoconazole (Systemic)

moderate

Ketoconazole potently inhibits CYP3A4 and P-glycoprotein, increasing cyclosporine levels 2-3 fold. Used therapeutically to reduce cyclosporine cost.

Management: When intentional: reduce cyclosporine dose by 50-75% and monitor trough levels. When unintentional: monitor for cyclosporine toxicity (vomiting, nephrotoxicity).

Meloxicam

moderate

Both cyclosporine and NSAIDs reduce renal blood flow via different mechanisms. Combined use increases nephrotoxicity risk.

Management: Monitor renal function closely. Ensure adequate hydration. Use lowest effective NSAID dose.

Itraconazole

moderate

Itraconazole inhibits CYP3A4 and P-glycoprotein, increasing cyclosporine levels (similar to ketoconazole but less potent).

Management: Reduce cyclosporine dose by 25-50%. Monitor cyclosporine trough levels.

Fluconazole

moderate

Fluconazole inhibits CYP3A4 (less potent than ketoconazole/itraconazole), increasing cyclosporine levels ~50%.

Management: Monitor cyclosporine levels. May need modest dose reduction.

Digoxin

moderate

Cyclosporine may increase digoxin levels via P-glycoprotein inhibition, reducing digoxin renal clearance.

Management: Monitor digoxin levels when adding cyclosporine.

Azithromycin

moderate

Azithromycin inhibits P-glycoprotein, potentially increasing cyclosporine levels. Less CYP3A4 inhibition than erythromycin or clarithromycin, but P-gp effect is relevant.

Management: Monitor cyclosporine levels if high-dose or prolonged azithromycin course. Usually clinically modest interaction.

Cannabidiol (CBD)

moderate

CBD inhibits CYP3A4 and P-glycoprotein, potentially increasing cyclosporine levels.

Management: Monitor cyclosporine levels when adding CBD. May need cyclosporine dose reduction.

Metoclopramide

moderate

Metoclopramide increases GI motility, potentially increasing cyclosporine absorption rate and peak levels.

Management: Monitor cyclosporine levels if metoclopramide added. Usually clinically modest effect.

Minor — 2

Enrofloxacin

minor

Enrofloxacin may modestly inhibit CYP3A4, slightly increasing cyclosporine levels. Clinical significance is minor compared to ketoconazole/itraconazole interaction.

Management: Usually clinically insignificant. Monitor cyclosporine levels if using high-dose enrofloxacin for prolonged courses.

Prednisolone

minor

Prednisolone may reduce cyclosporine clearance modestly. Both immunosuppressive — additive immune suppression. Intentionally used combination.

Management: Standard combination for IMHA and immune-mediated disease. Monitor for infection.

Educational reference only

Brands

Other markets

Atopica

Neoral

Sandimmune

FAQs

Frequently asked questions

›What is Cyclosporine (Systemic)?

Cyclosporine (Systemic) is a calcineurin inhibitor / immunosuppressant used in pets. Binds cyclophilin forming a complex that inhibits calcineurin phosphatase, blocking IL-2 transcription and T-lymphocyte activation. Suppresses cell-mediated immunity without significant myelosuppression.

›What is Cyclosporine (Systemic) used for in pets?

Cyclosporine (Systemic) is used in veterinary medicine for: FDA-approved (Atopica) for canine atopic dermatitis; FDA-approved for feline allergic dermatitis.

›What is the Cyclosporine (Systemic) dose for dogs?

For dogs, Cyclosporine (Systemic) is typically dosed as follows — FDA-approved (Atopica) for canine atopic dermatitis: 5–10 mg/kg PO q24h (dermatitis) or q12h (immune-mediated). Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What is the Cyclosporine (Systemic) dose for cats?

For cats, Cyclosporine (Systemic) is typically dosed as follows — FDA-approved for feline allergic dermatitis: 7 mg/kg PO q24h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›Does Cyclosporine (Systemic) need a prescription?

Yes. Cyclosporine (Systemic) is a prescription medication and should only be administered under veterinary supervision.

Educational reference only

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

Plumb's Veterinary Drug Handbook
Withrow & MacEwen's Small Animal Clinical Oncology
Merck Veterinary Manual
NRC Nutrient Requirements of Dogs and Cats
Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

ASPCA Animal Poison Control Center Guidelines
AAHA Diabetes Management Guidelines
ASPCA Poison Control Guidelines
RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

EPIC Study (J Vet Intern Med 2016)
JVIM FAT CAT Study

Regulatory & approvals — 1

CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

Washington State University VCPL MDR1 Database