Fexofenadine

Category: pharmacological

Aliases: Allegra

Pharmacological Mechanism

Second-generation H1 antagonist — active metabolite of terfenadine (pulled from market for QT). No CNS sedation; no QT signal. P-glycoprotein substrate (grapefruit juice lowers F).

Half-Life (t½)

PO: 3.75h

Dosing Guidelines

• PO: Typical 180 mg (Range: 60–180 mg)

Target Organ Systems

• digestive

Pathways It Modulates

• Histamine receptor pharmacology (inhibitor) — H1 (2nd-gen, fully peripheral)

Chemical Identifiers

• PubChem CID: 3348
• Formula: C32H39NO4
• Molecular weight: 501.66 g/mol
• InChIKey: RWTNPBWLLIMQHL-UHFFFAOYSA-N
• SMILES: CC(C)(C1=CC=C(C=C1)C(CCCN2CCC(CC2)C(C3=CC=CC=C3)(C4=CC=CC=C4)O)O)C(=O)O

References

• PMID 19660947