Old versus new antihistamines: Effects on cognition and psychomotor functions

Antihistamines (AHs) are the most widely long-term therapeutic option to manage allergic diseases. This research aimed to study the effects of long-term administration of AHs: on cognitive (memory, mood, attention, sleep and executive function) and psychomotor performance.

This prospective, observational study for a total duration of 30 months was carried out at the Dermatology OPD in adult patients with dermatological condition who were newly prescribed either chlorpheniramine (4 mg, BD), levocetirizine (10 mg, OD), fexofenadine (180 mg, OD) or bepotastine (10 mg, BD) for at least 28 days as per inclusion and exclusion criteria after taking written informed consent. A detailed history of the patients, memory (using PGI memory scale) and psychomotor functions, Brief Mood Introspection Scale and Epworth Sleepiness Scale were assessed at baseline, 1 week and 4 weeks. Data obtained were analysed using paired sample t-test and one-way ANOVA followed by post hoc analysis (P-value <0.05 statistically significant).

A total of 22 in chlorpheniramine group, 23 in levocetirizine group, 20 in fexofenadine group and 18 in bepotastine group were analysed. Chlorpheniramine and levocetirizine had deteriorating effects on cognitive and psychomotor performance, whereas fexofenadine and bepotastine showed positive effect on various cognitive and psychometric tasks. The study results showed chlorpheniramine and levocetirizine to be having sedative effects, whereas fexofenadine was nonsedating. In bepotastine group, no effect on sleep was observed. No significant difference in mood scores was observed in between chlorpheniramine, levocetirizine and fexofenadine groups. In bepotastine group, arousal calm and positive tired scores increased at 4 week as compared to baseline.

Patients with dermatological illnesses can be prescribed fexofenedine and bepotastine, as compared to chlorpheniramine and levocetirizine, and their cognitive and psychological functions should be evaluated periodically with suitable tests.