Posted by John Try your user ID again, I reset it today. Also email to you was getting returned to me as “Undeliverable" so make sure that I have the correct address. That can mess it up too. A lot of stuff can affect cyclosporine levels, many drugs raise levels, a few drop levels. A common pharmacokinetic interaction involves drugs that interfere with the absorption of other medications. Drugs that bind (eg, cholestyramine) potentially decrease the gastrointestinal absorption of another drug (eg, tacrolimus). Typically administering the agents 2-3 hours apart can prevent this interaction. Prokinetic agents (eg, metoclopramide) interfere with the rate of absorption. Since many transplant patients take prokinetic agents, this may increase the bioavailability of other medications. This is of clinical significance with immunosuppressive agents, such as cyclosporine. If the prokinetic agent cannot be avoided, careful monitoring (eg, serum drug levels, clinical presentation of patient) and adjustments should be made to prevent immunosuppressant toxicity. CYP-450 Inhibition Cyclosporine and tacrolimus are two of the most commonly used immunosuppressants in renal transplant patients. Both cyclosporine and tacrolimus are metabolized by the 3A-4 subfamily of the cytochrome P450 (CYP-450) system. This system is responsible for the metabolism of more than 30% of drugs, and therefore many medications that induce or inhibit the CYP-450 system are commonly administered and may potentially cause a drug interaction. Examples of classes that inhibit the CYP-450 system include azole antifungals, macrolide antibiotics, and calcium channel antagonists.[6,7,10-12] Examples of drugs that induce the CYP-450 system include phenytoin and rifampin.[6] Although it is difficult to predict the onset of the interaction on an individual basis, the time to onset is related to the half-life of the drugs involved and the half-life of enzyme production. Significant drug interactions of this type have been known to cause nephrotoxicity, neurotoxicity, and graft rejection.[10] Many transplant patients have hyperlipidemia and are frequently prescribed HMG-CoA reductase inhibitors. Cyclosporine, tacrolimus, and sirolimus may interact with HMG-CoA reductase inhibitors, which could result in increased serum concentrations of HMG-CoA reductase inhibitors up to 20-fold.[13] This interaction can result in serious injury by causing rhabdomyolysis, acute renal failure, and even graft loss. It is recommended when using these agents in combination with cyclosporine, tacrolimus, or sirolimus to begin therapy with a low-dose HMG-CoA reductase inhibitor and to obtain baseline and follow-up creatinine phosphokinase measurements every 6 months. http://www.medscape.com/viewarticle/408586_3? There are other foods I am sure but more things raise levels than lower them, so also look at drugs at you used to take and do not take now.
on 6/12/2003, 10:46 am, in reply to "Things that affect cyclosporin levels"
Hi,
Pharmacokinetic Drug Interactions
HMG-CoA Reductase Inhibitors
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