For elderly patients (65 years and older), consider a lower starting dose of cetirizine hydrochloride, perhaps 5-10 mg once daily. Closely monitor their response to treatment. Renal function significantly impacts cetirizine elimination.
Patients with renal impairment require dose adjustments. For those with creatinine clearance (CrCl) of 31-50 mL/min, reduce the dose to 10 mg once daily. If CrCl is 11-30 mL/min, use 5 mg once daily. Individuals with CrCl below 10 mL/min should avoid cetirizine or use it very cautiously under close medical supervision. Always consult a doctor or pharmacist before modifying cetirizine dosage based on renal function.
