Parkinson’s disease
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.
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.
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.