What is the maximum dose of cyclosporine (cyclosporin) for a patient with psoriasis, including those with morbid obesity, and does the recommended dose range of 2.5-5 mg/kg/day apply to all patients regardless of weight, such as a patient weighing 200 kg?

Maximum Dosage of Cyclosporine for Psoriasis Patients, Including Those with Morbid Obesity

The maximum dose of cyclosporine for psoriasis is 4 mg/kg/day, with a standard dosing range of 2.5-5 mg/kg/day based on actual body weight, even for patients with morbid obesity weighing 200 kg or more. 1

Dosing Guidelines for Cyclosporine in Psoriasis

Initial Dosing

• Start at 2.5 mg/kg/day, divided into two daily doses (1.25 mg/kg twice daily) 1
• Maintain this dose for at least 4 weeks before considering dose adjustments 1
• Some clinicians prefer starting at an intermediate dose of 2.5-3.0 mg/kg/day given twice daily 2

Dose Adjustments

• If significant clinical improvement has not occurred after 4 weeks, increase dose by approximately 0.5 mg/kg/day at 2-week intervals 1
• Maximum dose should not exceed 4 mg/kg/day 1
• Dose increases should be based on clinical response and tolerability 2

Efficacy at Different Doses

• At 3 mg/kg/day: 50-70% of patients achieve PASI 75 and 30-50% achieve PASI 90 2
• At 5 mg/kg/day: 50-97% of patients achieve PASI 75 2
• At 2.5 mg/kg/day: 28-85% of patients achieve PASI 75 2

Special Considerations for Obese Patients

Weight-Based Dosing in Obesity

• The standard weight-based dosing of 2.5-5 mg/kg/day applies to all patients regardless of weight, including those with morbid obesity weighing 200 kg 2, 1
• There is no established maximum absolute dose (in mg) for very heavy patients

Fixed-Dose Alternative

• One study found that fixed doses of cyclosporine microemulsion (100 mg once daily or 50 mg twice daily) were effective in patients weighing 50-80 kg 3
• Improvement rates were 69.4% ± 4.8% in the once-daily group and 73.4% ± 4.3% in the twice-daily group 2, 3
• However, this approach has not been validated in morbidly obese patients weighing 200 kg

Monitoring and Safety Considerations

Renal Function

• Nephrotoxicity is one of the most common adverse effects of cyclosporine 2
• Reversible nephrotoxicity develops in 19-24% of patients during short-term treatment 2
• If treatment continues for more than 2 years, the risk of fibrosis and irreversible kidney damage increases substantially 2
• Over 50% of patients demonstrate an increase in serum creatinine over 30% of baseline when treated with cyclosporine for longer than 2 years 2

Dose Adjustments for Safety

• Decrease dose by 25-50% if adverse events occur, such as:
  • Hypertension
  • Elevations in serum creatinine (≥25% above patient's pretreatment level)
  • Clinically significant laboratory abnormalities 1
• If dose reduction is not effective in controlling abnormalities or if the adverse event is severe, discontinue cyclosporine 1

Duration of Treatment

• Continuous treatment for periods greater than one year is not recommended 1
• Consider alternating with other forms of treatment for long-term management 1

Practical Recommendations

• Calculate dose based on actual body weight, even in morbidly obese patients
• Monitor renal function and blood pressure closely, especially in patients receiving higher total doses
• Consider maintenance therapy at 3 mg/kg/day after achieving clearance, which can maintain remission in 58% of patients for 6 months 4
• For patients with morbid obesity, be particularly vigilant about monitoring for adverse effects due to the higher absolute dose
• Consider weight loss interventions as an adjunctive therapy, as one study showed improved PASI 75 response (66% vs 29%) in patients who lost weight 2

Remember that while the standard dosing range is 2.5-5 mg/kg/day, the FDA-approved maximum dose for psoriasis is 4 mg/kg/day, and this applies to all patients regardless of weight 1.