Levodopa + Carbidopa
Dosage Form: Tablet.
This tablet is indicated for the treatment of Parkinson’s disease and syndrome. It is useful in relieving many of the symptoms of parkinsonism, particularly rigidity and bradykinesia. This tablet is frequently helpful in the management of tremor, dysphagia, sialorrhea and postural instability associated with Parkinson’s disease and syndrome. Levodopa plus carbidopa before physiotherapy increases motor recovery after stroke.
The combination of levodopa and carbidopa is used to treat Parkinson’s disease and Parkinson’s-like symptoms that can occur after encephalitis (brain swelling) or a nervous system injury caused by carbon monoxide poisoning or manganese poisoning. Tremors (shaking), stiffness, and slowness of movement are all symptoms of Parkinson’s disease, which is caused by a shortage of dopamine, a natural substance found in the brain. Levodopa belongs to a class of drugs known as central nervous system agents. It functions by converting dopamine in the brain. Carbidopa belongs to the class of drugs known as decarboxylase inhibitors. It works by blocking the breakdown of levodopa before it reaches the brain. This enables a lower dose of levodopa to be used, resulting in less nausea and vomiting.
If 100/10 mg tablet is used: Dosage may be initiated with one tablet three or four times a day. Titration upward may be required in some patients to achieve optimum dosage of carbidopa. The dosage may be increased by one tablet every day or every other day until a total of eight tablets (two tablets q.d.s.) is reached.
For patients starting with 250/25 mg tablet: The initial dose is one half taken once or twice daily. However, this may not provide the optimal amount of Carbidopa needed by many patients. If necessary, add one-half 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 one tablet of 250/25 mg three or four times a day.
Maintenance dose: Therapy should be individualized and adjusted according to the desired therapeutic response. When more levodopa is requried, 250/25 mg tablet should be substituted at a dosage of one tablet three or four times a day. If necessary, the dosage of 250/25 mg tablet may be increased by half to one tablet every other day to a maximum of eight tablets a day. Experience with a total daily dosage greater than 200 mg Carbidopa is limited.
Route of administration: Orally.
Symptomatic postural hypotension has occurred when Carbidopa-Levodopa is added to the treatment of a patient receiving antihypertensive medicines. Therefore, when therapy with CarbidopaLevodopa is started, dosage adjustment of the antihypertensive medicine may be required. There have been rare reports of adverse reactions, including hypertension and dyskinesia, resulting from the concomitant use of tricyclic antidepressants and Carbidopa-Levodopa. Studies demonstrate a decrease in the bioavailability of Carbidopa and/or Levodopa when it is ingested with ferrous sulphate or ferrous gluconate. Dopamine-2 receptor antagonists (e.g., phenothiazines, butyrophenones and risperidone) and isoniazid may reduce the therapeutic effects of Levodopa. In addition, the beneficial effects of Levodopa in Parkinson’s disease have been reported to be reversed by phenytoin and papaverine. Patients taking these medicines with Carbidopa-Levodopa should be carefully observed for loss of therapeutic response. Concomitant therapy with selegiline and Carbidopa-Levodopa may be associated with severe orthostatic hypotension not attributable to Carbidopa-Levodopa alone.
Patients with hypersensitivity to Carbidopa and Levodopa, as well as those with narrow-angle glaucoma, should avoid taking the Carbidopa-Levodopa pill. Carbidopa-Levodopa should not be taken in people with suspected unexplained skin lesions or a history of melanoma because Levodopa can trigger a malignant melanoma.
Adverse effects that occur frequently in patients receiving Carbidopa-Levodopa are those due to the central neuropharmacologic activity of dopamine. These reactions usually can be diminished by dosage reduction. The most common adverse effects are dyskinesias including choreiform, dystonic, and other involuntary movements and nausea.
- Body as a whole: syncope, chest pain, anorexia.
- Cardiovascular: palpitation, orthostatic effects including hypotensive episodes, hypertension, phlebitis.
- Gastrointestinal: vomiting, gastrointestinal bleeding, development of duodenal ulcer, diarrhoea, dark saliva.
- Haemotologic: leukopenia, haemolytic and non-haemolytic anaemia, thrombocytopenia, agranulocytosis.
- Hypersensitivity: angioedema, urticaria, pruritus, Henoch-Schonlein purpura.
- Nervous System: dizziness, somnolence, paresthesia, delusions, hallucinations and paranoid ideation, depression with or without development of suicidal tendencies, dementia, dream abnormalities, agitation, confusion, increased libido.
- Respiratory: dyspnea.
- Skin: alopecia, rash, dark sweat.
- Urogenital: dark urine.
Pregnancy & Lactation:
Although the effect of carbidopa and levodopa on human pregnancy is unclear, levodopa and the combination of carbidopa and levodopa have caused rabbit visceral and skeletal malformations. Therefore, the use of carbidopa and levodopa in women of childbearing age requires a balance between the expected benefits of the drug and the potential risks of pregnancy. It is not clear whether carbidopa is excreted in human milk. Since many drugs are excreted from human milk, and because of the possibility of serious adverse reactions in nursing infants, it is necessary to decide whether to stop breastfeeding or stop using carbidopa-levodopa, taking into account the importance of the drug. Mother.
Precautions & Warnings:
Arbidopa-Levodopa is not recommended for the treatment of medicine-induced extrapyramidal reactions. Carbidopa Levodopa may be given to patients already taking Levodopa alone; however, the Levodopa must be discontinued at least 12 hours before Carbidopa-Levodopa started. Dyskinesias may occur in patients previously treated with Levodopa alone because Carbidopa permits more Levodopa to reach the brain and, thus, more dopamine to be formed. The occurrence of dyskinesias may require dosage reduction. All patients should be observed carefully for the development of depression with concomitant suicidal tendencies. Patients with past or current psychoses should be treated with caution. Carbidopa-Levodopa should be administered cautiously to patients with severe cardiovascular or pulmonary disease, bronchial asthma, renal, hepatic or endocrine disease, or a history of peptic ulcer disease or of convulsions.
Care should be exercised to patients with a history of myocardial infarction who have atriai, nodal, or ventricular arrhythmia. In such patients, cardiac function should be monitored with particular care during the period of initial dosage administration and titration. Patients with chronic wide-angle glaucoma may be treated cautiously with Carbidopa-Levodopa, provided the intraocular pressure is weli controlled and the patient monitored carefully for changes in intraocular pressure during therapy.
Use in children: Safety and effectiveness of Carbidopa-Levodopa in infants and children have not been established, and its use in patients below the age of 18 years is not recommended.
Store in a cool and dry place, protected from light.
Manufactured by: UniMed UniHealth Pharmaceuticals Ltd.