List of cytochrome P450 modulators

Cytochrome P450 modulators are compounds that influence the activity of the cytochrome P450 enzymes, a large family of enzymes that play a crucial role in the metabolism of drugs and the synthesis and breakdown of lipids, steroids, and other molecules within the body. These modulators can either inhibit or induce the activity of various cytochrome P450 enzymes, thereby affecting the metabolism of numerous drugs and potentially leading to drug interactions. Understanding the modulators of cytochrome P450 is essential for predicting drug interactions and for the development of new therapeutics.

Types of Cytochrome P450 Modulators

Cytochrome P450 modulators can be broadly classified into two categories: inhibitors and inducers.

Cytochrome P450 Inhibitors

Inhibitors of cytochrome P450 enzymes decrease the metabolic activity of the enzyme, leading to increased plasma levels of drugs metabolized by the enzyme. This can enhance the drugs' effects and increase the risk of side effects.

• CYP1A2 Inhibitors: Include compounds like fluvoxamine and ciprofloxacin.
• CYP2C9 Inhibitors: Such as sulfamethoxazole and fluconazole.
• CYP2C19 Inhibitors: Include omeprazole and fluoxetine.
• CYP2D6 Inhibitors: Comprise drugs like quinidine and paroxetine.
• CYP3A4 Inhibitors: Include potent inhibitors like ketoconazole and clarithromycin.

Cytochrome P450 Inducers

Inducers of cytochrome P450 enzymes increase the metabolic activity of the enzyme, leading to decreased plasma levels of drugs metabolized by the enzyme. This can reduce the drugs' efficacy.

• CYP1A2 Inducers: Include compounds like omeprazole and cigarette smoke.
• CYP2C9 Inducers: Such as rifampin and barbiturates.
• CYP2C19 Inducers: Include rifampin and St. John's Wort.
• CYP2D6 Inducers: Few known inducers, but some compounds may have mild inducing effects.
• CYP3A4 Inducers: Include potent inducers like rifampin, phenytoin, and carbamazepine.

Clinical Significance

The modulation of cytochrome P450 enzymes has significant clinical implications. It is crucial in the context of drug-drug interactions, where one drug affects the metabolism of another, potentially leading to toxic levels or reduced efficacy of the affected drug. Understanding the modulatory effects of compounds on cytochrome P450 enzymes is essential for the safe and effective use of drugs, particularly in polypharmacy where multiple drugs are prescribed.

List of Cytochrome P450 Modulators

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See Also

• Drug metabolism
• Pharmacokinetics
• Drug interaction