Twindopa(Levodopa & Carbidopa)
Therapeutic Group: Others
Presentation
Twindopa 110: Each tablet contains Levodopa BP 100 mg and Carbidopa BP 10 mg.
Twindopa 125: Each tablet contains Levodopa BP 100 mg and Carbidopa BP 25 mg.
Twindopa 275: Each tablet contains Levodopa BP 250 mg and Carbidopa BP 25 mg.
Description
Symptoms of Parkinson’s disease are currently believed to be attributed to depletion of dopamine in the corpus striatum. Levodopa, the metabolic precursor of dopamine, does cross the blood-brain barrier, and presumably is converted to dopamine in the brain. This is thought to be the mechanism whereby levodopa relieves symptoms of Parkinson’s disease.
Indications
Levodopa & Carbidopa tablet is indicated in the treatment of the symptoms of idiopathic Parkinson’s disease, post-encephalitic parkinsonism and symptomatic parkinsonism which may follow injury to the nervous system by carbon monoxide intoxication and/or manganese intoxication.
Dosage & Administration
For Usual Initial Dosage:
Patients not presently receiving levodopa:
• If Levodopa 100 mg & Carbidopa 10 mg tablet is used, dosage may be initiated with 1 tablet 3 or 4 times a day. Titration upward may be required in some patients to achieve optimum dosage of carbidopa (70-100 mg/day). The dosage may be
increased by 1 tablet every day or every other day until a total of 8 tablets (2 tablets q. d. s.) is reached.
• When Levodopa 100 mg & Carbidopa 25 mg tablet is used, dosage is initiated with 1 tablet of Levodopa 100 mg & Carbidopa 25 mg tablet, 3 times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by 1 tablet every day or every other day, as necessary, until a dosage of 8 tablets of Levodopa 100 mg &
Carbidopa 25 mg a day is reached.
• For patients starting with Levodopa 250 mg & Carbidopa 25 mg tablet, the initial dose is ½ tablet & taken 1-2 times a day. However, this may not provide the optimal amount of carbidopa needed by many patients. If necessary, add ½ tablet every day or every other day until optimal response is reached. The suggested starting dosage for most patients taking more than 1500 mg of Levodopa a day is 1 tablet of Levodopa 250 mg & Carbidopa 25 mg, 3-4 times daily
Side Effects
The most common adverse reaction with Levodopa & Carbidopa are nausea, choreiform dystonia & other involuntary movements. Other significant reactions are convulsions, dementia & mental changes. The mental changes include paranoid ideation, psychotic episodes & depression with or without suicidal tendencies.
Precautions
Levodopa alone, as well as combination, is associated with dyskinesias. The occurrence of dyskinesias may require dosage reduction. It should be administered cautiously to patients with severe cardiovascular or pulmonary disease, bronchial asthma, renal, hepatic or endocrine disease.
Use in Pregnancy & Lactation
Pregnancy: Pregnancy Category C.
Lactation: Levodopa has been detected in human milk. Caution should be exercised when administered to a nursing woman.
Use in Children: Safety & effectiveness of Carbidopa-Levodopa in infants & children have not been established, and its use in patients below the age of 18 years is not recommended.
Drug Interaction
Pyridoxine reverses effects of levodopa. Type B MAOIs have synergistic effect. Effect reduced by phenothiazines, haloperidol, reserpine, pyridoxine, diazepam, oxazepam, chlordiazepoxide, phenobarbitone. Effects of levodopa enhanced by carbidopa, amantadine, anticholinergics, amphetamine. Effects of sympathomimetic agents enhanced.
Over Dose
Management of acute overdose with Carbidopa-Levodopa is basically the same as management of acute over dosage with levodopa; however pyridoxine is not effective in reversing the actions of Carbidopa-Levodopa. For the possible development of arrhythmias; if required, appropriate anti-arrhythmic therapy should be given. The terminal half-life of levodopa is about two hours in the presence of carbidopa
Storage
Do not store above 30 C. Keep away from light and out of the reach of children.
Commercial Pack
Twindopa 110: Each box containing 3 blister strips of 10 tablets.
Twindopa 125: Each box containing 3 blister strips of 10 tablets.
Twindopa 275: Each box containing 3 blister strips of 10 tablets.
