Bosentan could induce the metabolism of amiodarone while amiodarone may inhibit bosentan metabolism. A study of the concurrent administration of inhibitor ritonavir and inducer St. John's wort revealed a predominant effect of enzyme inhibition.EBSCO_AspPharmacy Times...
Recently a study was done to examine the effects of ritonavir (a CYP3A4 inhibitor) and St. John’s wort (a CYP3A4 inducer) alone and in combination on the metabolism of midazolam.1 Twelve subjects received single oral doses of midazolam alone and with single doses of St. John’s wort...
7 Cigarettes also induce certain P450 enzymes, and can increase dose requirements for some drugs, for example, the dose requirements for theophylline are higher in smokers than in non-smokers. Table 2. Examples of some clinically important interactions caused through enzyme induction InducerInteracted ...
Hopefully, though, newer models for studying human gut wall metabolic extraction will provide the means to predict the average extraction ratio and maximum first-pass availability of a putative substrate, or the range of possible inhibitory or inductive changes for a putative inhibitor/inducer. 展开 ...
Theoretical plasma concentration–time profiles of a drug in the presence of a CYP enzyme inducer (dashed line) and inhibitor (solid line). In reversible inhibition, enzymatic activity is regained by the systemic elimination of inhibitor, such that the time to enzyme recovery is dependent on the...
induced enzyme(inducible enzyme) one whose production requires or is stimulated by a specific small molecule, the inducer, which is the substrate of the enzyme or a compound structurally related to it. proteolytic enzymeone that catalyzes the hydrolysis of proteins and various split products of prot...
The repressor theory is in good agreement with most of the observations which have been made on enzyme-inducing systems. The inducer need not be a substrate for the enzyme which is formed, nor need it serve as a template for the formation of new enzymes 1 . 展开 ...
Note that phenytoin is a CYP2C9 substrate,inhibitor, and inducer. Clinically,however, adverse outcomes primarilyhave been due to phenytoin's susceptibilityto toxicity when combined withCYP2C9 inhibitors and its ability to act asan inducer of CYP2C9 and other CYP450enzymes, thus reducing the eff...
Examples of enzyme inducers includeaminoglutethimide, barbiturates, carbamazepine, glutethimide, griseofulvin, phenytoin, primidone, rifabutin, rifampin, and troglitazone. Some drugs, such as ritonavir, may act as either an enzyme inhibitor or an enzyme inducer, depending on the situation. ...
Enzyme induction is important in the pathogenesis of hepatotoxicity and therapeutic failure of many drugs. Phenobarbital is a potent enzyme inducer known for hepatotoxicity and for inducing its own metabolism. Rifampin induces the metabolism of azole antifungals; concurrent administration with itraconazole ...