Tegral 200
Tablets
Antiepileptic Composition:
Each scored tablet contains:
Carbamazepine 200 mg Properties:
Tegral 200 tablets contains carbamazepine which is considered to be one of
the antiepileptic, psychotropic and neurotropic agents.
Generally, carbamazepine stabilizes hyperexcited nerve membrane, inhibits
repetitive neuronal discharges and reduces synaptic propagation of
excitatory impulses.
The antiepileptic properties of carbamazepine may be due to reduction of
glutamate release and stabilization of neuronal membranes.
Also, Tegral possesses antimanic effect which is mainly due to its depressant
effect on dopamine and noradrenaline turnover.
As a neurotropic, Tegral prevents paroxysmal attacks of pain in idiopathic
or secondary trigeminal neuralgia. It is useful in relief of neurogenic pain in
a variety of conditions including post-traumatic paraesthesia and post- herpetic neuralgia.
In alcohol withdrawal syndrome, Tegral raises the lowered convulsion
threshold and improves withdrawal symptoms.
In diabetes insipidus centralis, Tegral reduces the urinary volume and
relieves the feeling of thirst. Pharmacokinetics:
Tegral is absorbed almost completely, reaches peak plasma concentration within 12 hours, it is widely distributed through out the body, bound to serum proteins to the extent of 70-80%. It crosses the placental barrier and is secreted in breast milk.
It is metabolized in liver to carbamazepine-10,11-epoxide, which is equipotent to carbamazepine as an anticonvulsant and excreted in the urine and faeces. Indications & usage
Tegral tablets is the drug of choice for treatment of the following cases:
Epilepsy: -
- Complex or simple partial seizures (with or without loss of consciousness)
with or without secondary generalization. - Generalized tonic - clonic seizures (Grand mal).
- Mixed forms seizures. N.B: Tegral is not effective in treatment of absences (petit mal) or myoclonic seizures.
Idiopathic trigeminal neuralgia.
Idiopathic glossopharyngeal neuralgia.
Acute mania and maintenance treatment of bipolar disorders.
Painful diabetic neuropathy.
Diabetic insipidus centralis.
Polyuria and polydipsia of neurohormonal origin.
Symptoms of the alcohol withdrawal syndrome Contra-indications:
- Hypersensitivity to Carbamazepine or structurally related drugs.
- Patients with atrioventricular block.
- History of bone marrow depression.
- Porphyria.
- Concomitant use of MAOIs: treatment with MAOIs should be discontinued
for 2 weeks or longer before administration of carbamazepine. Side effects:
At the start of treatment by Tegral or if the initial dosage is too high or when treating elderly patients, a certain types of adverse reactions may occur such as:
CNS: Dizziness, ataxia, headache, fatigue, diplopia, accommodation disorders
(e.g. blurred vision) ; uncommon abnormal involuntary movement.
Rarely : speech disorders, peripheral neuritis, paraesthesia , restlessness,
hallucination, depression, loss of appetite, confusion.
Cardiovascular system : rarely ; disturbance in cardiac conduction and blood pressure.
Very rare: bradycardia, arrhythmia, thromboembolism or lymphadenopathy.
Blood disorders: Leucopenia, thrombocytopenia, eosinophilia .
Allergic skin reactions: urticaria, rash; rarely : lupus erythematosus like
syndrome; very rare: Stevens-Johnson syndrome. toxic epidermal necrolysis,
alopecia , photosensitivity reactions.
Gastro-intestinal tract: Nausea, vomiting
Liver: elevated gamma-GT (due to hepatic enzyme induction), elevated
alkaline phosphatase ; uncommon elevated transaminases ; rarely hepatitis.
§ Urogenital system: very rare (acute renal failure, renal dysfunction, urinary
sexual disturbances).
§ Endocrine system and metabolism: Hyponatraemia, oedema, disturbance
of bone metabolism ; very rare : galactorrhea, gynecomastia .
§ Respiratory system: very rare pulmonary hypersensitivity characterized by
fever , dyspnoea and pneumonitis.
§ Musculoskeletal system: Arthralgia, muscle pain.
§ Sense organs :Very rare (taste disturbances, lens opacities, conjunctivitis,
hearing disorders). Drug interactions:
Coadministration of inhibitors of CYP 3A4 (the main enzyme catalyzing the formation of carbamazepine-10,11-epoxide) may result in increase plasma concentrations which could induce adverse reactions Coadministration of CYP 3A4 inducers might increase the rate of Carbamazepine metabolism, thus leading to decreasing the therapeutic effects.
§ Drugs that may increase plasma carbamazepine levels include :-
Dextropropoxyphene, isoniazid, clarithromycin, erythromycin, fluoxetine,
itraconazole, fluconazole, loratadine, diltiazem, verapamil, acetazolamide,
danazol, cimetedine, terfenadine.
§ Drugs that may decrease plasma carbamazepine levels include:
Phenobarbital, isotretinoin, phenytoin, theophylline, rifampicin, cisplatin,
doxorubic |
