CYP3A4
Liver oxidation catalyst
CYP3A4 is a liver enzyme responsible for metabolizing roughly half of all pharmaceutical drugs.
It belongs to the cytochrome P450 family—proteins that break down foreign substances in the body.
Because so many medications pass through CYP3A4, drug interactions are common: grapefruit juice famously inhibits it, causing some drugs to accumulate to dangerous levels.
Doctors and pharmacists monitor CYP3A4 interactions closely when prescribing multiple medications.
Body's chemical processing of medications
- biotransformationMetabolic chemical conversion
- first-pass effectDrug breakdown before systemic circulation
- oxidationLosing electrons chemically
- cyclosporineImmunosuppressive transplant drug
statins · benzodiazepines · opioids · antiretrovirals · substrate · metabolite · hepatocyte · pharmacokinetics
Many forms, one interface
- pharmacogenomicsGene-based drug response study
- genotypingAnalyzing DNA variants
- alleleGene variant at one locus
- personalized medicineTreatment based on individual traits
Pressed citrus drink, bitter
- ketoconazoleAntifungal pharmaceutical agent
- clarithromycinMacrolide antimicrobial medication
- erythromycinMacrolide antimicrobial medication
- verapamilCalcium channel blocking agent
drug interaction · toxicity · contraindication · furanocoumarins · overdose risk · irreversible
Anticonvulsant blocking sodium channels
- phenobarbitalBarbiturate anticonvulsant sedative
- St John's wortMedicinal yellow-flowered herb
- dexamethasoneSynthetic corticosteroid reducing inflammation
- CAREngineered immune receptor
Iron-porphyrin complex in blood
- ironElement twenty-six
- endoplasmic reticulumCytoplasmic membrane network for synthesis
- active siteEnzyme region binding substrates
- protein structureBiomolecule's three-dimensional form
drug metabolism
Body's chemical processing of medications
- biotransformationMetabolic chemical conversion
- first-pass effectDrug breakdown before systemic circulation
- oxidationLosing electrons chemically
cyclosporine · statins · benzodiazepines · opioids · antiretrovirals · substrate · metabolite · hepatocyte · pharmacokinetics · bioavailability
polymorphism
Many forms, one interface
- pharmacogenomicsGene-based drug response study
- genotypingAnalyzing DNA variants
- alleleGene variant at one locus
personalized medicine · genetic testing · haplotype · ancestry · variant
grapefruit juice
Pressed citrus drink, bitter
- ketoconazoleAntifungal pharmaceutical agent
- clarithromycinMacrolide antimicrobial medication
- erythromycinMacrolide antimicrobial medication
verapamil · drug interaction · toxicity · contraindication · furanocoumarins · overdose risk · irreversible
phenytoin
Anticonvulsant blocking sodium channels
- phenobarbitalBarbiturate anticonvulsant sedative
- St John's wortMedicinal yellow-flowered herb
- dexamethasoneSynthetic corticosteroid reducing inflammation
heme
Iron-porphyrin complex in blood
- ironElement twenty-six
- endoplasmic reticulumCytoplasmic membrane network for synthesis
- active siteEnzyme region binding substrates
- pharmacogenomicspharmacogenomics, drug metabolism, genotyping, CYP2D6, CYP enzymes
- CYP enzymesCYP2D6, aromatase
- Drug Metabolismbiotransformation, drug metabolism, metabolite, metabolites, conjugation
- Metabolic EnzymesCYP2D6, GST, N-acetyltransferase, NAT, MAO
- Oxidoreductasesoxidase, peroxidase, catalase, CYP2D6, MMO
- PharmacogenesCYP2D6
CYP3A4ketoconazole
Antifungal pharmaceutical agent
clarithromycin · grapefruit juice · St. John's wort · phenytoin