Sulfamethoxazole

Category: pharmacological

Aliases: Component of Bactrim / Septra

Pharmacological Mechanism

Sulfonamide antibiotic — competitive inhibitor of bacterial dihydropteroate synthase (DHPS) blocking folate synthesis. Always co-formulated with trimethoprim for synergistic folate-pathway blockade. CYP2C9 inhibitor (raises warfarin INR).

Half-Life (t½)

PO: 10h, IV: 10h

Dosing Guidelines

• PO: Typical 800 mg (Range: 800–1600 mg)

Target Organ Systems

• digestive
• immune-hematologic

Pathways It Modulates

• Bacterial DNA replication + folate synthesis (inhibitor) — DHPS (folate synthesis)

Chemical Identifiers

• PubChem CID: 5329
• Formula: C10H11N3O3S
• Molecular weight: 253.28 g/mol
• InChIKey: JLKIGFTWXXRPMT-UHFFFAOYSA-N
• SMILES: CC1=CC(=NO1)NS(=O)(=O)C2=CC=C(C=C2)N

References

• PMID 8696062