Can I use levocetirizine (levocet) and cyproheptadine together, spacing 12 hours between doses, for 5 days?

Using Levocetirizine and Cyproheptadine Together

Taking levocetirizine (Levocet) and cyproheptadine 12 hours apart for 5 days is generally acceptable, but caution is advised due to potential additive sedative effects that may impact your daily functioning.

Mechanism and Classification

• Levocetirizine is a non-sedating second-generation H1 antihistamine taken once daily, primarily used for allergic conditions including urticaria 1
• Cyproheptadine is a sedating first-generation H1 antihistamine with additional antiserotonergic and anticholinergic properties 1

Safety Considerations

Potential Benefits

• The combination of a non-sedating antihistamine during the day and a sedating antihistamine at night is a common practice that may help with nighttime symptoms 1
• Cyproheptadine's additional antiserotonergic properties may help with gastrointestinal symptoms that can accompany urticaria 1

Potential Concerns

• Sedating antihistamines like cyproheptadine can cause daytime drowsiness even when taken at night 2
• Despite common belief, adding a sedating antihistamine at night may not provide additional clinical benefit if the H1 receptor is already saturated by the non-sedating antihistamine 1
• Cyproheptadine can cause anticholinergic side effects such as dry mouth and blurred vision 1

Recommendations for Use

Dosing Schedule

• Take levocetirizine in the morning and cyproheptadine at night to minimize daytime sedation 1
• Spacing the medications 12 hours apart as proposed is appropriate to minimize potential drug interactions 1

Monitoring

• Be alert for excessive sedation, especially when driving or operating machinery 1
• If sedation becomes problematic, consider discontinuing cyproheptadine while continuing levocetirizine 2
• A 5-day course is reasonable for short-term symptom management 1

Special Considerations

Renal Function

• If you have moderate renal impairment, the dose of levocetirizine should be halved 1
• In severe renal impairment (creatinine clearance <10 mL/min), levocetirizine should be avoided altogether 1

Hepatic Function

• Cyproheptadine should be used with caution in hepatic impairment 1

Alternative Approaches

• If symptoms are not adequately controlled, guidelines suggest increasing the dose of levocetirizine up to 4 times the standard dose before adding other medications 3
• For difficult-to-treat urticaria, increasing levocetirizine dosage has shown better efficacy than adding a sedating antihistamine 3

Conclusion

While using levocetirizine and cyproheptadine together with 12-hour spacing for 5 days is generally acceptable, be aware of potential sedation. If you experience excessive drowsiness, consider using levocetirizine alone, potentially at a higher dose if needed for symptom control.