What is the maximum dose of cyclosporine (cyclosporin) for a patient with psoriasis, particularly in cases of morbid obesity, and should the dose be calculated based on actual weight or ideal body weight, even for patients weighing over 70 kilograms (kg)?

Maximum Cyclosporine Dosing in Psoriasis Patients with Morbid Obesity

For patients with psoriasis, including those with morbid obesity, the maximum dose of cyclosporine should not exceed 5 mg/kg/day based on actual body weight, with no absolute upper limit regardless of the patient's weight. 1, 2

Dosing Recommendations for Cyclosporine in Psoriasis

Initial Dosing

• Start with 2.5-3 mg/kg/day divided into two doses 1, 2
• Maintain this dose for at least 4 weeks before considering dose adjustments 2
• For patients with more severe disease, some clinicians start at 5 mg/kg/day with subsequent stepwise decreases after disease control is achieved 1

Dose Adjustments

• If insufficient response after 4 weeks, increase dose by approximately 0.5 mg/kg/day at 2-week intervals 2
• Maximum dose should not exceed 5 mg/kg/day 1
• Once adequate control is achieved, reduce to the lowest effective maintenance dose 2

Weight Considerations in Obese Patients

Despite some clinical opinions suggesting dose limitations based on ideal body weight, the current guidelines and FDA labeling clearly indicate:

• Cyclosporine should be dosed based on actual body weight, even in obese patients 1
• The FDA-approved labeling for cyclosporine specifically states that "obese patients often require dosing based on their actual weight" 1
• There is no maximum weight cutoff (such as 70 kg) mentioned in any of the current guidelines or FDA labeling 1, 2

Monitoring and Safety Considerations

Careful monitoring is essential, especially in obese patients who may be at higher risk for adverse effects:

• Monitor blood pressure and serum creatinine every 2 weeks during the first 3 months, then monthly if stable 1
• Reduce dose by 25-50% if serum creatinine increases >25% above baseline on two occasions separated by 2 weeks 1
• If creatinine remains elevated despite dose reduction, consider discontinuing cyclosporine 1
• For long-term therapy (>1 year), yearly glomerular filtration rate measurements are recommended 1

Duration of Therapy

• Cyclosporine is ideally used as interventional therapy rather than continuous long-term treatment 1, 3
• Short courses (12-16 weeks) are associated with minimal toxicity in healthy patients 1
• Long-term continuous treatment beyond 2 years significantly increases the risk of irreversible renal damage 1, 3
• Consider intermittent courses with drug-free intervals or rotation with other therapies for long-term management 2, 3

Important Cautions

• Nephrotoxicity risk increases with treatment duration - 19-24% with short-term use, >50% with treatment >2 years 1
• Hypertension is a common side effect and should be closely monitored 1
• Weight loss in obese patients may improve cyclosporine efficacy 1
• Avoid concomitant medications that may interact with cyclosporine, including NSAIDs, aminoglycosides, and certain antifungals 1

In conclusion, while there may be clinical opinions suggesting dose limitations based on ideal body weight, the current evidence-based guidelines and FDA labeling clearly support dosing cyclosporine based on actual body weight, even in morbidly obese patients, with a maximum of 5 mg/kg/day.