Dogretole (TABLETS)
Antiepileptic

COMPOSITION:
Each tablet contains 200mg carbamazepine.

INDICATIONS:
Dogretole is used in the treatment of:

  • Generalized tonic-clonic and partial seizures.
  • Paroxysmal pain of trigeminal neuralgia.
  • Prophylaxis of manic-depressive psychosis in patients unresponsive to lithium therapy.

DOSAGE:

  • Epilepsy:

Adults: Initial dose is 100–200mg once or twice daily and gradually increased until the best response is obtained which is about 800-1200mg daily. In some cases 1600mg daily may be necessary.
Children: A gradually increasing dosage scheme is used and this should be adjusted to suit the needs of the individual patient. 
5 – 10 years: 200mg 2-3 times daily.
10 – 15 years: 200mg 3-5 times daily.

  • Trigeminal neuralgia: It varies considerably depending on the age and weight of the patient. Initial dose is 200–400mg daily and may be increased gradually to 200mg 3-4 times daily.
  • Manic-depressive psychosis in patients unresponsive to lithium therapy: Initial dose is about 400mg daily in two divided doses and increased gradually to 400 – 600mg daily, given in divided doses.

SIDE EFFECTS:
Dogretole is generally well tolerated, but side effects may occur particularly at the beginning of treatment, manifested as:
Central nervous system: dizziness, ataxia, drowsiness, fatigue, headache, diplopia, accommodation disorders.
Skin: allergic skin reactions, urticaria.
Blood: leucopenia, thrombocytopenia, eosinophillia.
Liver: elevated gama-GT, elevated alkaline phosphatase.
Gastrointestinal tract: nausea, vomiting, dryness of mouth.
Others: oedema, weight increase, hyponatraemia.
In very rare cases: Anemia, cardiac arrhythmia, Stevens-Johnson syndrome, hepatitis of cholestatic, parenchymal or mixed type, jaundice.
The dose related adverse reactions usually abate within a few days, either spontaneously or after transient dosage reduction.  

CONTRAINDICATIONS:
Known hypersensitivity to carbamazepine or structurally related drugs, (e.g. tricyclic antidepressants) or any other component of the formulation. Patients with atrioventricular block, a history of previous bone marrow depression or a history of acute intermittent porphyria.

DRUG INTERACTIONS:

  • In patients receiving oral anticoagulant medication, it is necessary to adjust the dosage when Dogretole is prescribed.
  • Dogretole may also reduce the activity of oral contraceptive hormones, so it is recommended to use non-hormonal method of contraception.
  • Dogretole should not be given to patients taking a mono-amino oxidase inhibitor and Dogretole should not be given before two weeks of stopping such treatment.
  • Certain drugs elevate carbamazepine levels, such as: Macrolide antibiotics (erythromycin), isoniazid, some calcium antagonists (verapamil, diltiazem), dextropropoxyphene, and possibly cimetidine.
  • The metabolism of Dogretole is enhanced by concomitant use of CYP 3A4 inducers, phenobarbitone, phenytoin and primidone.
  • The combination of lithium and Dogretole may cause enhanced neurotoxicity of lithium in spite of being within the therapeutic range of lithium plasma concentrations.
  • Alcohol may exacerbate the CNS side effects; it is therefore advisable that the patient abstain from alcohol drinking during treatment.

PRECAUTIONS:

  • Complete pre-treatment blood counts, including platelets and possible reticulocytes and serum iron, should be obtained as a base line, and periodically thereafter.  
  • If reactions such as fever, sore throat, rash, ulcer in the mouth, easy bruising, petechial or purpuric hemorrhage appear, the patient should be advised to consult his physician immediately.
  • Carbamazepine should be used with caution in patients with mixed seizures which include absences, either typical or atypical.
  • Liver function tests should be performed before commencing treatment and periodically thereafter, particularly in patients with a history of liver disease and in elderly patients. The drug should be withdrawn immediately in cases of aggravated liver dysfunction or acute liver disease.
  • Carbamazepine should be prescribed only after a critical benefit-risk appraisal and under close monitoring in patients with a history of cardiac, hepatic or renal damage, adverse haematological reactions to other drugs. 
  • Treatment should not be stopped abruptly and the doctor should be consulted.
  • Baseline and periodic complete urinalysis and BUN determination are recommended.
  • Carbamazepine has shown mild anticholinergic activity; patients with increased intraocular pressure should therefore be warned and advised regarding possible hazards. 
  • Patients taking carbamazepine and requiring oral contraception should receive a preparation containing not less than 50µg estrogen or use of some alternative non hormonal method of contraception should be considered.

Effects on ability to drive and use machines:
Patients should be warned when operating machinery because of the incidence of dizziness.

USE IN PREGNANCY AND LACTATION:
Dogretole should be avoided during pregnancy and lactation and the judgment is up to the doctor.

PHARMACOKINETIC PROPERTIES:
Absorption: carbamazepine is absorbed almost completely but relatively slowly from the tablets. The conventional tablets yield mean peak plasma concentrations of the unchanged substance within 12 hours following single oral doses.
The bioavailability of carbamazepine in various oral formulations has been shown to lie between 85-100%.
Food has no significant influence on the rate and extent of absorption of carbamazepine.
Distribution: carbamazepine is bound to serum proteins to the extent of 70-80%.
Concentrations in breast milk were found to be equivalent to 25-60% of the corresponding plasma levels. Carbamazepine crosses the placental barrier.    
Elimination: the elimination half life of unchanged carbamazepine averages approximately 36 hours following a single dose, whereas after repeated administration it averages only 16-24 hours, depending on the duration of medication.
The elimination half life is affected by some concomitant treatment with other enzyme-inducing drugs, half-life values averaging 9-10 hours have been found.
After administration of a single dose of 400mg carbamazepine, 72% is excreted in the urine and 28% in the feces.

PRESENTATION:
Carton pack contains 2 or 5 blisters of 10 tablets in each, with leaflet.

 

 
 
 

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