Details

Autor(en) / Beteiligte

• G.Wari, Umesh

Titel

A Comparative Study of the Anticonvulsant Effect of Three Calcium Channel Blockers and Sodium Valproate in Albino Rats

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

2006

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• Epilepsy is one of the most common afflictions of man with a prevalence of approximately 0.3-0.5% in different population. It has important medical, social, psychological consequences.Even though it was recognised as early as 2000 B.C. new concepts about its pathogenesis, etiology and treatment are brought out almost every year. In the past the treatment of the epilepsy was based on superstitious religious beliefs and ignorance. But the present day concept of treatment of epilepsy is very much different from what it was earlier.The investigators who have worked on epilepsy have used various chemicals for treating epilepsy, starting from bromides. [which provides the first rational treatment for patients suffering from epilepsy.] to recent newer antiepileptics. Inspite of the vast number of drugs introduced for the treatment of epilepsy, there is still a need for an ideal antiepileptic agent with properties like broad spectrum activity, rapid onset of action, least side effects, good oral bioavailability and low cost.The calcium channel blockers have established themselves as very effective therapeutic agents in various disorders of the cardiovascular system. Many tissues outside the CVS are functionally dependent upon the influx of extracellular calcium through various channels on the cell membrane. It is clear that Calcium Channel Blockers may be of value in treating many pathological states where over activity of calcium channels is apparent. Beneficial effects of CCBs have been found in various central nervous system disorders like nerve repair and regeneration migraine etc.Epilepsy is one such disorder & experiments conducted on individual neurons shows that calcium ions play a decisive role in the origin of epileptic activity. Calcium influx is critical to the process of repetitive synchronus firing of neurons which leads to epilepsy. Voltage dependent calcium currents are believed to play multiple roles in epileptic events; they may contribute to the depolarization shift seen in focal epilepsy They may become active during the transition to seizures & spread of seizure activity & they may be particularly important in some forms of partial generalised epilepsy.Accordingly various antiepileptic drugs have been shown to reduce the transmembrane flux of Ca+2at therapeutic or higher concentrations.Three types of calcium channels [T, N & L ] that are modulated in a different manner by different drugs exist in neurons. The organic calcium channel antagonists are also classified in 4 structurally different classes. Each of them has a variable level of activity in different excitable tissues & therefore, they may also have differences in their major pharmacological actions & the clinical uses. It has rightly been suggested that CCBs have distinct subgroups that can be used as a basis for drug design & prediction of clinical efficacy at an early stage in drug development.Keeping this in view, a comparative evaluation of anticonvulsant activity of three different CCBs, namely nifedipine (a dihydropyridine), flunarizine (a piperizine) & diltiazem (a benzothiozepine) has been made using experimental models of epilepsy.