In recent years the pharmaceutical market has seen an influx in the number of new anti-epileptic drugs, and Topamax (topiramate) is on the list of these neoteric meds too. The preparation comes with topiramate in its composition, the active ingredient (added to the list of substances approved by FDA in 1998), developed and currently manufactured by Janssen-Cilag.
In vitro studies on experimental models convulsive states indicate that the drug is effective in terms of both partial and generalized seizures removal. Topiramate inhibits the onset of seizures in animals as a result of electric shock and prevents the development of seizures, generated by the amygdala. This makes it possible to predict the ability of the drug in clinical settings to prevent the generalization of seizure activity occurring in the amygdaloid area, ie in the event of amygdaloid epilepsy. In addition, topiramate increases the seizure threshold in convulsions induced by pentylenetetrazole, and slows tonic, as well as arising spontaneously seizures.
Experimental data also suggests that topiramate appears not just as an anticonvulsant, but also in a number of models of cerebroprotector organic CNS (embolism of the middle cerebral artery, perinatal hypoxia, nontraumatic compression of the thorax, bilateral occlusion of the carotid arteries, and neonatal status epilepticus seizures). Researchers assume that in clinical practice drug must have some cerebroprotective effect that a priori should contribute to a slowdown in the growth of epileptic personality changes and intellectual defect in patients with epilepsy, which leads to disruption of social adaptation and disability of patients on the basis of these experimental data.
It is well known that in effective long-term treatment of patients with epilepsy it is necessary to control the level of most classical antiepileptic drugs in blood plasma. For new anticonvulsant, which belong to topiramate, the need for monitoring the blood concentration is considerably less, due to the wider range of therapeutic compounds. It is believed that topiramate therapeutic range in plasma concentration is 3-15 mg/ml. In this context it emphasizes that topiramate is characterized by a linear dependence of the concentration level of the daily dose, which facilitates its use in practical conditions. According to the study, the optimal range of concentrations of the drug to prevent seizures is 7,12 ± 1,6 mg / ml. It is obvious that the fact that the linear dependence of the concentration of topiramate on the value of his daily dose eliminates the need for frequent monitoring of drug concentration.
How to use
In accordance with the instructions, Topamax during epileptic seizures is taken orally at 200 mg 2 times a day. If necessary, the contents of the capsule can be mixed with a small amount of water. Adult patients can take Topamax along with other anticonvulsants. The correct dosage must be established by the attending physician. At the early therapy stages the dosage is recommended to start from 25mg daily, following a gradual increase. Topamax is contraindicated in children under 2 years old; while in 2 – 10 years old kids the dose must not exceed 50mg daily. In those suffering from kidney disease, the treatment should start from the minimum possible dosage. As an additional antiepileptic, Topamax can be used in 9mg dose twice a day, and the course of treatment lasts 7 days. Topamax in migraine appointed to take 100 mg 2 times a day. In severe migraine attacks the dosage is increased up to 200mg, divided into 2 intakes.