Drug Monograph
Full clinical overview, indications, dosage references & safety notes.
Overview
Ciclosporin (Cyclosporine; Atopica®, Cyclavance®, Modulis®, Optimmune®, Sporimmune®) is an immunosuppressive drug widely used in veterinary medicine for immune-mediated and allergic diseases in dogs and cats. It acts primarily by inhibiting T-lymphocyte activation and reducing immune-mediated inflammation.
In small animal practice, ciclosporin is commonly used systemically for the management of atopic dermatitis and other immune-mediated conditions. It may also be administered topically as an ophthalmic ointment for immune-mediated keratoconjunctivitis sicca (KCS) in dogs and may provide benefit in chronic superficial keratitis (pannus).
Mechanism of Action (MOA): Ciclosporin selectively inhibits T-lymphocyte activation by interfering with calcineurin-dependent signaling pathways. This prevents transcription of cytokines such as interleukin-2 that are required for T-cell proliferation and immune activation, resulting in targeted immunosuppression.
Ciclosporin is available in multiple formulations including oral capsules, oral solutions, injectable preparations, and ophthalmic ointments. Because of its immunosuppressive effects, active bacterial or fungal infections should be appropriately treated before initiating therapy.
Indications
Ciclosporin is used in veterinary medicine primarily as an immunomodulatory and immunosuppressive agent for allergic and immune-mediated diseases in dogs and cats. Both topical ophthalmic and systemic formulations are used depending on the clinical condition being treated.
- Keratoconjunctivitis sicca (KCS): Topical ophthalmic preparations are commonly used to treat immune-mediated dry eye in dogs by stimulating tear production and reducing ocular inflammation.
- Chronic superficial keratitis (pannus): Ophthalmic ciclosporin may help suppress immune-mediated corneal inflammation and improve ocular comfort in affected dogs.
- Atopic dermatitis: Oral formulations are licensed for the management of canine and feline atopic dermatitis and help reduce pruritus and allergic skin inflammation.
- Perianal fistulas: Systemic ciclosporin may be used to suppress immune-mediated inflammation associated with perianal fistula disease in dogs.
- Sebaceous adenitis: Used as part of immunomodulatory therapy to control inflammation and improve clinical signs in dogs with sebaceous gland disease.
- Immune-mediated diseases: Ciclosporin may be included in treatment protocols for various immune-mediated disorders where suppression of T-lymphocyte activity is beneficial.
Dosage (Reference)
Dog
In dogs, ciclosporin may be administered topically for ocular immune-mediated disease or systemically for dermatologic and immune-mediated conditions. Clinical response may require several weeks of therapy.
| Clinical use | Route | Dose | Frequency | Notes |
|---|---|---|---|---|
| Ocular disease (e.g., KCS, pannus) | Topical ophthalmic | Apply ~0.5 cm ointment to affected eye | Every 12 hours | Clinical improvement usually occurs in 2–4 weeks but may take up to 12 weeks. |
| Atopic dermatitis | PO | 5 mg/kg | Every 24 hours | Continue until clinical signs are controlled. |
| Perianal fistula / sebaceous adenitis | PO | 5 mg/kg | Every 24 hours | In non-responsive cases, dosing may be increased to every 12 hours. |
| Immune-mediated disease | PO | 5 mg/kg | Every 12 hours | Some patients may require higher doses; pharmacodynamic monitoring may be needed. |
• Improvement in ocular disease may take several weeks (commonly 2–4 weeks, occasionally up to 12 weeks).
• Once tear production becomes excessive, topical treatment may be reduced to every 24 hours with careful monitoring.
• Dose adjustments may be necessary in dogs that do not respond adequately to standard therapy.
Cat
In cats, ciclosporin is most commonly used for allergic or immune-mediated dermatologic conditions. Dosing strategies may vary depending on disease severity and clinical response.
| Clinical use | Route | Dose | Frequency | Notes |
|---|---|---|---|---|
| Atopic dermatitis | PO | 7 mg/kg | Every 24 hours | Continue until clinical signs are controlled. |
| Immune-mediated disease | PO | 3–5 mg/kg or 5–7 mg/kg |
Every 12 hours Every 24 hours |
Dosing protocols are variable and should be adjusted based on clinical response. |
• Response to therapy may vary between individuals.
• Dosing regimens may require adjustment depending on disease severity and response to treatment.
Warnings & Precautions
Ciclosporin is a potent immunosuppressive drug and should be used cautiously in veterinary patients. Appropriate patient selection, monitoring, and infection control are important when initiating therapy.
- Active infections: Bacterial and fungal infections should be treated before starting ciclosporin therapy because immunosuppression may worsen existing infections.
- Renal impairment: Although significant nephrotoxicity is less common in dogs than in humans, ciclosporin should be used cautiously in patients with renal dysfunction and renal parameters (e.g., creatinine) should be monitored regularly.
- Diabetes mellitus: Ciclosporin may reduce circulating insulin levels and increase blood glucose and fructosamine concentrations. Glycaemic control should be closely monitored in diabetic patients.
- Age and body weight restrictions: Systemic administration is not recommended in dogs or cats younger than 6 months of age, in dogs weighing less than 2 kg, or in cats weighing less than 2.3 kg.
- Malignant disease: Do not use in animals with progressive malignant disorders because immunosuppression may increase the risk of tumor progression.
- Vaccination considerations: Live vaccines should not be administered during treatment or within two weeks before or after ciclosporin therapy because immune responses to vaccination may be reduced.
- Viral infections in cats: The manufacturer does not recommend use in cats infected with feline leukemia virus (FeLV) or feline immunodeficiency virus (FIV).
- Handling precautions: Use protective gloves when handling the drug to minimize the risk of cutaneous absorption.
Drug Interactions
Ciclosporin is extensively metabolized by hepatic cytochrome P450 enzymes and is also a substrate and inhibitor of the P-glycoprotein (MDR1) transporter. Drugs that affect these metabolic pathways may significantly alter ciclosporin blood concentrations or increase the risk of toxicity.
- Cytochrome P450 inhibitors (e.g., diltiazem, doxycycline, imidazole antifungals): These drugs can reduce ciclosporin metabolism and increase circulating drug concentrations.
- Itraconazole and ketoconazole: These antifungals can increase ciclosporin blood levels in dogs by up to five-fold. When used concurrently, the ciclosporin dose may need to be reduced or the dosing interval increased.
- Nephrotoxic drugs (e.g., aminoglycosides, NSAIDs, quinolones, trimethoprim–sulphonamides): Concurrent administration may increase the risk of nephrotoxicity and is generally not recommended.
- ACE inhibitors: Combined use may increase the risk of hyperkalaemia.
- P-glycoprotein substrates (e.g., macrocyclic lactones such as ivermectin or milbemycin): Ciclosporin may inhibit drug efflux at the blood–brain barrier, potentially increasing the risk of central nervous system toxicity.
Side Effects & Overdose
Side Effects
Adverse effects associated with ciclosporin are generally mild and reversible in dogs and cats. Most reactions occur following systemic administration and often resolve after dose adjustment or discontinuation of therapy.
- Topical ocular reactions: Immediate discomfort or blepharospasm may occur after ophthalmic application in some dogs.
- Gastrointestinal effects: Transient vomiting and diarrhea may occur after oral administration; these reactions are usually mild and do not require discontinuation of treatment.
- Reduced appetite: Anorexia may occasionally develop during systemic therapy.
- Gingival hyperplasia: Mild to moderate gingival enlargement may occur during prolonged treatment.
- Dermatologic changes: Hypertrichosis, papillomatous skin lesions, and red or swollen pinnae have been reported in some animals.
- Neuromuscular effects: Muscle weakness and muscle cramps may occur infrequently.
- Increased malignancy risk: Both systemic and topical therapy may be associated with an increased risk of malignancy due to immunosuppressive effects.
- Toxoplasmosis risk in cats: Cats that are seronegative for Toxoplasma gondii may develop clinical toxoplasmosis if infection occurs during treatment.
Overdose
Specific overdose reports for ciclosporin in veterinary patients are limited. However, excessive dosing may increase the likelihood of gastrointestinal and immunosuppressive adverse effects.
- Gastrointestinal signs: Vomiting, diarrhea, or anorexia may occur with excessive dosing.
- Exaggerated immunosuppression: High systemic exposure may increase susceptibility to infections or other complications related to immune suppression.
- Management: Treatment is primarily supportive and may include discontinuation of therapy, symptomatic treatment, and monitoring of clinical status.
Key Notes
Practical clinical considerations that may help optimize the safe and effective use of ciclosporin in veterinary patients:
- Delayed onset of effect: Clinical improvement with systemic therapy, particularly for dermatologic disease, may take several weeks before noticeable improvement occurs.
- Long-term therapy: Ciclosporin is often used as a long-term management drug for chronic allergic or immune-mediated diseases once clinical control is achieved.
- Individual variability: Response to ciclosporin therapy varies among patients, and dose adjustments may be necessary to achieve optimal clinical response.
- Pharmacodynamic monitoring: In some patients receiving systemic therapy, monitoring drug response and adjusting treatment protocols may be necessary to ensure effective immunosuppression.
- Multiple formulations available: Ciclosporin is available in oral capsules, oral solutions, injectable preparations, and ophthalmic ointments, allowing treatment to be tailored to the clinical condition.
- Specialist use in ophthalmology: Topical ciclosporin is widely used in veterinary ophthalmology to manage immune-mediated ocular surface disease.
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