COMPARATIVE EVALUATION OF CNS DEPRESSIVE ACTIVITY OF CHLORPHENIRAMINE MALEATE AND EBASTINE IN WISTAR RATS USING ROTARAD AND PHOTOACTOMETER
DOI:
https://doi.org/10.22159/ijcpr.2026v18i1.8030Keywords:
Chlorpheniramine maleate, CNS depression, Ebastine, Photoactometer, Rotarod, Wistar ratsAbstract
Objective: Allergic conditions are commonly treated with Antihistamines. Though the first-generation H1 antihistamines like Chlorpheniramine Maleate (CPM) are effective, they can cause sedation because of its blood-brain barrier crossing capacity leading to central nervous system (CNS) depression. But Ebastine, a 2nd-generation H1 antihistamine, is considered to be a non-sedating drug because of its limited CNS penetration. Hence, evaluating the CNS effects of these drugs is crucial for guiding safe and rational clinical practice. Aim of this study was to compare the CNS depressant effects of Chlorpheniramine Maleate and Ebastine in Wistar rats using Rotarod and Photoactometer behavioral models.
Methods: This was a prospective cross-sectional study conducted at Department of Pharmacology, Government Villupuram Medical College and Hospital, Villupuram, Tamilnadu, India between January to June 2025. Eighteen adult Wistar rats were randomly assigned into three groups, with 6 rats in each group viz, Group 1: Control rats receiving Normal saline, Group 2: rats receiving CPM and Group 3: rats receiving Ebastine. CNS activity was assessed 60 min after drug administration. Motor coordination was measured using the Rotarod test and locomotor activity was assessed using a digital photoactometer. Data were analyzed using one-way ANOVA followed by Tukey’s post hoc test.
Results: Chlorpheniramine Maleate significantly reduced the fall-off time on the Rotarod (71.6±7.8 sec) and decreased locomotor activity (124.2±14.8 counts), indicating CNS depression (p<0.01). Ebastine-treated rats showed no significant difference in either parameter compared to the control group (fall-off time: 139.7±12.6 sec; locomotor activity: 284.4±19.2 counts).
Conclusion: Chlorpheniramine Maleate produces significant CNS depressant activity while Ebastine does not impair motor coordination or spontaneous activity in rats. These findings support the evidence that Ebastine as a non-sedating antihistamine and favor its use in clinical practice where sedation is undesirable.
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