Bilastine is Non-Sedating
Bilastine is a non-sedating second-generation antihistamine that does not cause sedation or performance impairment at recommended doses, making it suitable for patients who need to maintain alertness during daily activities. 1, 2
Classification and Mechanism
- Bilastine is classified as a second-generation H1 antihistamine with high selectivity for the H1 receptor and no affinity for other receptors 2
- The drug does not cross the blood-brain barrier in detectable amounts, which explains its lack of central nervous system effects 2
- Unlike first-generation antihistamines that require CNS penetration for efficacy in conditions like motion sickness, bilastine's peripheral action is sufficient for treating allergic conditions 3
Evidence for Non-Sedating Properties
Objective Performance Testing
- Bilastine 20 mg showed no impairing effects on sleepiness levels, vigilance, or complex task performance for up to 6 hours post-dose in hypobaric chamber testing at 8000 ft cabin altitude 4
- In the same study, hydroxyzine 50 mg (a first-generation antihistamine) caused significant sleepiness and impaired performance, confirming the test sensitivity 4
- Bilastine 20 mg performed similarly to placebo in driving tests, meeting current criteria for non-sedating medications 2
Psychomotor Assessment Studies
- A 2024 study comparing bilastine formulations (oral, IV, and IM) to dexchlorpheniramine found that dexchlorpheniramine showed fast onset of drowsiness with decreased attention and coordination, while all bilastine formulations showed no sedative effects 5
- Bilastine does not increase alcohol effects on the CNS, unlike cetirizine 2
- Bilastine 20 mg does not increase the CNS depressant effect of lorazepam 2
Clinical Context: Comparison to Other Second-Generation Antihistamines
While bilastine is clearly non-sedating, it's important to understand the spectrum of sedation risk among second-generation antihistamines:
- Truly non-sedating at recommended doses: Fexofenadine, loratadine, desloratadine, and bilastine 6, 1
- May cause sedation at recommended doses: Cetirizine (13.7% vs 6.3% placebo) and intranasal azelastine 6
- Bilastine's safety profile in terms of adverse effects is very similar to placebo across all Phase I, II, and III clinical trials 2
Practical Considerations
Dosing and Administration
- Bilastine 20 mg once daily is the standard dose for allergic rhinoconjunctivitis and urticaria 1, 7
- Important caveat: Bilastine should be taken at least one hour before and no sooner than two hours after a meal, as food slows absorption 1
- The drug can be safely used at doses up to fourfold higher than standard (80 mg once daily) for refractory urticaria without sedation 7
Special Populations
- Bilastine is considered safe for pilots and personnel in safety-sensitive jobs due to its lack of effect on flying-related performance 4
- No dose adjustment is required in renal impairment, and hepatic impairment is not expected to increase systemic exposure above the safety margin 7
- The drug does not interact with the cytochrome P450 system, suggesting very low potential for drug-drug interactions 7
Common Pitfall to Avoid
Do not confuse bilastine with first-generation antihistamines or even with cetirizine—bilastine has a superior non-sedating profile that makes it particularly appropriate when cognitive performance and alertness are critical priorities for the patient.