Cyclosporine 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. 

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

Kuster GM, Drexel H, Bleisch JA, Rentsch K, Pei P, Binswanger U, Amann FW. Relation of cyclosporine blood levels to adverse effects on lipoproteins. Transplantation 1994 57(10) 1479-83. 

Watkins PG, Hamilton TA, Annesley TM, et al. The erythromycin breath test as a predictor of cyclosporine blood levels. Clin Pharmacol Ther 1990 48 120-129. 

Bourbigot B, Guiserix J, Airiau J, BressoUette L, Morin JF, Cledes J. Nicardipine increases cyclosporin blood levels. Lancet 1986 1(8495) 1447. 

Garraffo R, Monnier B, Lapalus P, Duplay H. Pristinamycin increases cyclosporin blood levels.Jk/e(Sfi5dRe5(1987) 15,461. 

Borras-Blasco J, Conesa-Garcia V, Navarro-Ruiz A, Marin-Jimenez F, Gonzalez-Delgado M, Gomez-Corrons A. Ciprofloxacin, but not levofloxacin, affects cyclosporine blood levels in a patient with pure red blood cell aplasia. Am J Med Sci (2005) 330,144-6. 

Fourtounas C, Kopelias I, Kiriaki D, Agroyannis B. Increased cyclosporine blood levels after nisoldipine administration in a renal transplant recipient. Transplint (2002) 15, 586-8. 

Hall TG. Effect of methylprednisolcne on cyclosporine blood levels. Pharmaco req y (1990)10,248. 

Hricik DE, Moritz C, Mayes JT, Schulak JA Association of the absence of steroid therapy widi increased cyclosporine blood levels in renal tran lant recipients Transplantation (1990) 49,221-3. 

Cyclosporine and tacrolimus are substrates of the drug-metabolizing isoenzyme CYP3A4. Multiple case reports have demonstrated that St. John s wort decreases blood levels of cyclosporine (Ahmed et al. 2001 Alscher and Klotz 2003 Barone et al. 2000 Beer and Ostermann 2001 Breidenbach et al. 2000a, 2000b Karliova et al. 2000 Mai et al. 2000 Mandelbaum et al. 2000 Moschella and Jaber 2001 Ruschitzka et al. 2000 Turton-Weeks et al. 2001). St. John s wort consumption for as little as 3 days was correlated with decreased cyclosporine blood levels (Mandelbaum et al. 2000). 

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... 

Drug interactions Sandostatin has been associated with changes in nutrient absorption, so it may effect the absorption of orally administered drugs. Concomitant administration of Sandostatin with cyclosporine may decrease blood levels of cyclosporine and result in transplant rejection. Patients receiving insulin, oral hypoglycemic agents, beta blockers. 

Posaconazole is the newest triazole to be licensed in the USA. It is available only in a liquid oral formulation and is used at a dosage of 800 mg/d, divided into two or three doses. Absorption is improved when taken with meals high in fat. Posaconazole is rapidly distributed to the tissues, resulting in high tissue levels but relatively low blood levels. Visual changes have not been reported, but drug interactions with increased levels of CYP3A4 substrates such as tacrolimus and cyclosporine have been documented. 

Tacrolimus can be administered orally or intravenously. The half-life of the intravenous form is approximately 9-12 hours. Like cyclosporine, tacrolimus is metabolized primarily by P450 enzymes in the liver, and there is potential for drug interactions. The dosage is determined by trough blood level at steady state. Its toxic effects are similar to those of cyclosporine and include nephrotoxicity, neurotoxicity, hyperglycemia, hypertension, hyperkalemia, and gastrointestinal complaints. 

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

Calcium channel blockers are considered the drug of first choice for the treatment of posttransplant I hypertension since they increase renal blood flow. Nifedipine, isradipine and amlopidine show little interac-l tion with cyclosporine-A. Diltiazem and verapamil elevate cyclosporine-A levels. I... 

Sirolimus is metabolized by CYP2A4 and is a substrate of the P-glycoprotein drug efflux pump drugs like voriconazole, itraconazole, fluconazole and erythromycin increase its blood concentration. Conversely, the inducers of CYP3A4 will decrease blood levels of sirolimus. Cyclosporine increases the bioavailability of sirolimus, possibly due to P-GP inhibition and competition for CYP3A4. The bioavailability is more than 30-40% when the two drugs are administered 4 h apart and is more than... 

Cyclosporine may be given orally or intravenously. Cyclosporine is slowly and incompletely absorbed (20-50%) after oral administration. It has an elimination half-life of 24 hours. The absorbed drug is almost totally metabolized and excreted in the bile. The dosage is based on a predetermined therapeutic blood level, measured as the trough level in steady state. Cyclosporine is metabolized primarily by P450 isoforms, and there is a potential for many drug interactions. 

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