Oral immunosuppressant therapies

Oral immunosuppressant treatments have been shown to be effective for severe recalcitrant cases of eczema. They act by reducing inflammation and affecting lymphocytes. The only licensed oral therapy for atopic eczema is ciclosporin, an immune suppressant drug which is also used to prevent transplant rejection. In atopic eczema, ciclosporin is indicated for the short-term treatment (8 weeks) of patients with severe atopic eczema in whom conventional therapy is ineffective or inappropriate. The normal dosage is 2.5– 5 mg/kg/day given orally in two divided doses for a maximum of 8 weeks. Ciclosporin requires careful monitoring due to side effects; monitoring should be shared between primary and secondary care and involves the following:

• Blood pressure should be measured onceto twice-weekly for the first month, then monthly thereafter.
• Kidney function should be tested by blood and urine tests, especially creatinine levels.
• Other regular tests should include: complete blood count, liver function, fasting lipid levels, uric acid.

Ciclosporin can impair renal and liver function. Close monitoring of serum creatinine and urea is required and dosage adjustment may be necessary. Increases in serum creatinine and urea occurring during the first few weeks of ciclosporin therapy are generally dose-dependent and reversible and usually respond to dosage reduction. Apart from a reduction in renal function, other side effects include hypertension, hirsutism, loss of appetite and nausea, paraesthesia, tremor, sensitive and bleeding gums and an increased risk of infection. Ciclosporin can also increase the risk of developing skin cancer, in particular basal cell and squamous cell carcinoma. The increased risk of developing malignancies and lymphoproliferative disorders (including lymphomas), some with reported fatalities, appears to be related to the degree and duration of immunosuppression (Electronic Medicines Compendium, 2009b).

Other immunosuppressant agents used in severe atopic eczema are prescribed ‘off licence’ and include: Azathioprine (a thiopurine analogue drug that suppresses the immune system by altering white blood cell function), oral systemic corticosteroids, interferon gamma and intravenous immunoglobulin.