Cyclosporine monitoring blood levels

Clonidine may increase cyclosporine blood levels although only a single case report supports this, it would be prudent to monitor cyclosporine blood levels in a patient receiving clonidine. 

The answer is b. (Hardman, p 1299. Katzung, p 609.) Nephrotoxicity may occur in almost three-quarters of patients treated with cyclosporine. Regular monitoring of blood levels can reduce the incidence of adverse effects. 

Blood levels - Blood level monitoring of cyclosporine is a useful and essential component in patient management. While no fixed relationships have been established, blood concentration monitoring may assist in the clinical evaluation of rejection and toxicity, dose adjustments, and the assessment of compliance. 

Cyclosporine has no myelotoxicity but the drug is nephrotoxic. It is because of this nephrotoxicity that cyclosporine has a narrow therapeutic index that makes blood level monitoring necessary. Other toxicities include hypertension, hepatotoxicity, neurotoxicity, hirsutism, gingival hyperplasia and gastrointestinal disturbances. 

Cyclosporin, tacrolimus Probable induction of cytochrome P450 metabolic pathway Reduced blood levels Risk of rejection of transplant Monitor cyclosporine levels and stop SJW Readjust dose of cyclosporine if required... 

Erratic absorption of soft gelatin capsules and oral solution necessitates 2 Si. repeated monitoring of cyclosporine blood levels... 

Because of its potential for nephrotoxicity, tacrolimus blood levels and renal function should be monitored closely, especially when tacrolimus is used with other potentially nephrotoxic drugs. Coadministration with cyclosporine results in additive or synergistic nephrotoxicity therefore, a delay of at least 24 hours is required when switching a patient from cyclosporine to tacrolimus. As tacrolimus is metabolized mainly by CYP3A, the potential interactions described above for cyclosporine also apply for tacrolimus. 

The first human kidney and bone marrow transplants using cyclosporine were reported in 1978. Oral or intravenous cyclosporine is an immunosuppressant for transplantation of these and other organs and investigations are underway for its possible use in a variety of autoimmune diseases including rheumatoid arthritis, severe psoriasis, and Crohn s disease. Dose-dependent nephrotoxicity (261—264) remains the primary limitation of the dmg and necessitates close monitoring of patients, including measurement of dmg levels in blood. Cyclosporine research has been reviewed (265—274). 

Until cyclosporine blood trough concentrations reach preconversion levels, monitoring should be undertaken every 4 to 7 days... 

The rapid and unambiguous distinction of the various clinical situations that can occur following a kidney transplant remains a problem. For example, it is necessary to distinguish rejection which requires increased immunosuppressive therapy such as cyclosporin A (CyA), from tubular necrosis which can be caused by too high levels of CyA. At present, kidney function is generally characterized using the level of blood plasma creatinine as a monitor. However, the balance between rejection and tubular necrosis remains a difficult distinction and the only clear diagnosis is an invasive kidney biopsy. 

Tolerability in children is good, and most common adverse effects are limited to abdominal pain and headaches. Adverse effects such as renal toxicity were mild and reversible in a long-term multicenter study of safety of cyclosporine use in adults. Even so, appropriate monitoring parameters—electrolytes, renal function, complete blood counts, fasting lipid profiles, and uric acid levels—should be measured at baseline and periodically. Cyclosporine is also involved... 

Cyclosporine is effective in severe ulcerative colitis that has failed to respond adequately to glucocorticoid therapy. Between 50% and 80% of these severely ill patients improve significantly (generally within 7 days) in response to intravenous cyclosporine (2-4 mg/kg/day), sometimes avoiding emergent colectomy. Careful monitoring of cyclosporine levels is necessary to maintain a therapeutic level in whole blood of 300-400 ng/mL. 

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