Anxiety disorders are among the most prevalent mental disorders in the general
population. Nearly 30 million persons are affected in the United States, with women
affected nearly twice as frequently as men. These disorders are frequently treated using
benzodiazepines (Diazepam) and non-benzodiazepines (Zaleplon). Non-benzodiazepines
have replaced the benzodiazepines for anxiety treatment due to low risk of dependence
and CNS effects encouraging drug abuse.
This work was designed to investigate the toxicological overdose effect of zaleplon
and diazepam on behavior, blood pressure, heart rate, brain neurotransmitter content and
liver & kidney functions in rats.
Rats were divided into five groups: 1% Tween 80, p.o. (control), diazepam (1 & 4
mg/kg, p.o.) and zaleplon (1 & 4 mg/kg, p.o.). All groups were injected daily for four
weeks to perform the following: behavioral study (assessment of motor co-ordination and
anxiety performance), measurement of blood pressure & heart rate, determination of the
free amino acid and monoamine contents in the whole brain, determination of serum
aminotransferases activity, total protein, total and direct billirubin, creatinine & blood
urea nitrogen of experimental rats.
Zaleplon decreased motor co-ordination, blood pressure and heart rate with extent
lesser than diazepam. However, it decreased anxiety performance and brain monoamine
content with extent more than diazepam. While, diazepam increased brain amino acid
content, serum aminotransferases activity, total protein, total & direct billirubin,
creatinine and blood urea nitrogen by magnitude more than zaleplon.
These results suggest that: zaleplon is safer than diazepam in treatment of anxiety.