Cetirizine

Zyrtec

Antihistamine • Second-generation H1 antihistamine

CNS Depressant

Half-life

8.3 hours

Protein Binding

93%

Metabolized By

CYP3A4

External

Selective peripheral H1 receptor antagonist with minimal CNS penetration

Drug Class

Antihistamine

Subclass

Second-generation H1 antihistamine

Zyrtec

Half-life

8.3 hours

Time for plasma concentration to decrease by 50%

Protein Binding

93%

Fraction bound to plasma proteins

Therapeutic Index

Wide

Margin between therapeutic and toxic doses