Chronic Codeine Medication Causes Myelin Degeneration and Motor Impairment in Experimental Animals
DOI:
https://doi.org/10.9734/bpi/cerb/v9/10608FKeywords:
Codeine, substance abuse, dihydrocodeine, \(Archilin^{tm}\) codeine syrup, wistar ratsAbstract
This chapter aimed to understand the effects of oral codeine administration on the integrity of neurons of the cerebral cortex and cerebellum, and its behavioral implications in male Wistar rats.
The use of Over-the-counter (OTC) medication for cough has resulted in overuse or abuse due to its availability. The range of medicines available is often more restrictive compared to prescribed medicines, and there are often limitations to indications and doses, although there has been a trend towards increasing deregulation of medicines from prescription to OTC supply and most recently availability from Internet pharmacies. Thirty adult male Wistar rats were obtained and randomly divided into 5 groups: A, B, C, D, and E (n=6). Drugs used for the study were ArchilinTM with codeine syrup and Dihydrocodeine 30mg tablets. Group A was administered 0.5ml/kg of normal saline (Control). Groups B and C were treated with 1mg/kg and 2mg/kg of dihydrocodeine respectively; Group D and E received 2ml/kg and 4ml/kg of ArchilinTMcodeine syrup respectively. The normal saline, ArchilinTMcodeine syrup, and dihydrocodeine solutions were administered orally for 21 days. The experimental animals were subjected to neurobehavioral studies using beam walk and open field. The beam walking and open field results revealed that chronic codeine administration interfered with motor function in the experimental animals. Sections of the cerebral cortex and cerebellum of rats given normal saline showed normal myelin sheaths, whereas animals in the treatment group showed degenerating myelin compared to the control. Degradation of myelin in neurons of the cerebral cortex as seen in the study may have affected the conduction of electrical signals in neurons, this could, in turn, impair normal functions of the cerebral and cerebellar cortex, as such possibly explain the observed alteration in locomotion, general ambulatory activity and motor dysfunction in the present study.
The deterioration of myelin sheaths caused by chronic codeine use has been shown to impact both motor function and the conduction of electrical impulses in myelinated axons.
