Drugs Acting on Cardio-vascular & Respiratory

Analyzing the statements in relation to Overview of indigenous medicinal plants its active principles in therapeutic use:

The correct option is Option 3: Statement (I) is correct but Statement (II) is incorrect..

• Fundamental Objective of Biotransformation: The primary biological purpose of enzymatic drug metabolism (Phase I functionalization and Phase II conjugation) is to convert non-polar, lipid-soluble xenobiotics into polar, water-soluble (non-lipid soluble) metabolites.
• Elimination Rationale: Lipophilic molecules are passively reabsorbed across renal tubular epithelial membranes and cannot be excreted. Biotransformation generates hydrophilic ionized metabolites that are readily eliminated in urine and bile.

Correct option: (1) Convert lipid soluble drugs into nonlipid soluble metabolites

• Identification of Prodrug: Sulfasalazine is a classic prodrug.
• Activation Mechanism: Sulfasalazine is an azo-linked conjugate of 5-aminosalicylic acid (5-ASA / mesalamine) and sulfapyridine. It is poorly absorbed from the upper GIT; upon reaching the colon, bacterial azo-reductase enzymes cleave the azo bond, releasing active 5-ASA to exert local anti-inflammatory effects in the colonic mucosa.
• Active Drugs: Clonidine, hydralazine, and captopril (active sulfhydryl ACE inhibitor, unlike enalapril) are pharmacologically active in their administered forms.

Correct option: (1) Sulfasalazine

• Preeminent Cytochrome P450 Isozyme: CYP 3A4 (and related CYP 3A subfamily enzymes) is the most abundant cytochrome P450 isozyme in both mammalian liver and intestinal enterocytes.
• Substrate Breadth & Drug Interactions: CYP 3A4 is responsible for the oxidative metabolism of more than 50% of all therapeutic drugs across human and veterinary medicine. Because numerous drugs act as potent inhibitors (ketoconazole, erythromycin) or inducers (rifampin, phenobarbital) of CYP 3A4, it is heavily implicated in dangerous drug-drug interactions.

Correct option: (3) CYP 3A4