Does cetirizine (antihistamine) affect blood pressure?

Cetirizine and Blood Pressure: Safety Profile

Cetirizine does not significantly affect blood pressure and is considered safe for use in patients with hypertension, as it lacks the anticholinergic and cardiovascular effects seen with first-generation antihistamines. 1

Pharmacological Properties of Cetirizine

• Cetirizine is a second-generation H1 antihistamine with a zwitterionic structure (containing both acidic and basic components), which contributes to its favorable safety profile 2
• Unlike first-generation antihistamines, cetirizine has minimal anticholinergic effects that could potentially affect blood pressure 3
• Cetirizine has a rapid onset of action (peak plasma levels within 1 hour) and is primarily eliminated unchanged through renal excretion 4
• It has low potential for drug interactions as it has minimal interaction with hepatic cytochrome P450 enzymes 3, 2

Cardiovascular Safety Profile

• Cetirizine has been demonstrated to have no cardiac toxicity in clinical studies 3, 4
• In comparative analysis of second-generation antihistamines, cetirizine was found to be devoid of QTc prolongation effects that could lead to cardiac arrhythmias 1
• Unlike terfenadine and astemizole (older second-generation antihistamines that were withdrawn due to cardiac concerns), cetirizine does not cause significant ECG changes or cardiovascular effects 1
• Cetirizine is not listed among medications that can cause or worsen hypertension in major hypertension guidelines 5

Clinical Considerations

• Cetirizine may cause sedation, especially at higher doses, but this is not associated with blood pressure changes 5
• When considering antihistamines for patients with hypertension, cetirizine is a safer option compared to decongestant-containing products, which can raise blood pressure 5
• Decongestants (such as pseudoephedrine and phenylephrine) that are sometimes combined with antihistamines in over-the-counter products are α-adrenergic agonists that can increase blood pressure 5

Special Populations

• In patients with renal impairment, dose adjustment of cetirizine is necessary:
  • The dose should be halved in moderate renal impairment 5
  • Cetirizine should be avoided in severe renal impairment (creatinine clearance <10 mL/min) 5
• No specific dose adjustments are required for patients with hypertension who have normal renal function 5

Practical Recommendations

• When prescribing antihistamines to patients with hypertension:
  • Choose cetirizine or other second-generation antihistamines without decongestant components 5
  • Avoid combination products containing decongestants (pseudoephedrine, phenylephrine) as these can raise blood pressure 5
  • Consider alternative therapies for nasal congestion such as intranasal corticosteroids or saline irrigation rather than oral decongestants 5
• For patients requiring both antihistamine therapy and blood pressure control, cetirizine is a suitable option that will not compromise hypertension management 1

Monitoring Considerations

• No specific blood pressure monitoring is required when initiating cetirizine in patients with controlled hypertension 5
• When discontinuing cetirizine prior to allergy testing, allow 5-7 days for washout 5
• If sedation occurs with cetirizine (which may affect approximately 13.7% of patients), consider switching to a less sedating alternative such as fexofenadine or loratadine 5