Introduction

Phenytoin and carbamazepine are first-line antiepileptic drugs used for efficacy and low cost. Epilepsy occurs in all breeds of dogs. Rational polypharmacy is a treatment strategy for refractory epilepsy.

Aim

This study evaluated serum biochemistry with CBZ and/or PHE in Wistar rats.

Materials and Methods

Forty male Wistar rats divided into four groups of 10 animals each. Groups I (control, water - 2 ml/kg), II (carbamazepine - 20 mg/kg), III (phenytoin - 100 mg/kg), IV (carbamazepine + phenytoin - 20, 100 mg/kg, respectively) per os once daily for eight weeks; the rats were sacrificed, serum samples obtained for analysis of serum proteins and electrolytes. The research was conducted according to University guidelines on Animal Research and National Institutes of Health Guide for Care and Use of Laboratory Animals (1985). Values were expressed as mean +/- SEM, subjected to statistical analysis using repeated-measures ANOVA with Tukey's post-hoc test. Values of p < 0.05 were considered significant.

Results

There were increases in Na⁺ (p < 0.0001), albumin (p < 0.01) and globulin (p < 0.05); but K⁺ (p < 0.05) decreased in the treated rats. Hypokalaemia may be caused by increased activity of the adrenal cortex, body reclaims Na⁺ from urine and K⁺ excreted, thus, increased Na⁺ concentration in the CBZ group. PHE inhibits ADH release causing increased water reabsorption in the kidneys, also, reverses hyponatraemia induced by CBZ therapy. Increased production of cortisol by the adrenal glands due to oxidative stress caused by metabolites of CBZ and PHE may cause increased albumin; decreased IgA, IgG by CBZ and PHE caused reduced globulin.

Conclusion

In conclusion, the administration of CBZ and/or PHE altered serum biochemistry of the treated rats.