Adult:
Start with L-dopa 100 mg + carbidopa 25 mg given tid. Increase by 1 tab/day every 1-2 days up to a max. of 8 tabs of any strength/day. If the patient has been taking L-dopa alone, the combination should be started after a gap of at least 8 hr after stopping L-dopa.
Precautions
Heart disease, liver disease, dementia, psychosis, pregnancy, elderly, heart disease. Regular monitoring of renal and hepatic functions is reccomended.
Potentially Life-threatening
Adverse Drug Reactions
Nausea, vomiting, anorexia, increased risk of GI bleeding in peptic ulcer patients. Orthostatic hypotension, cardiac arrhythmias. Psychiatric symptoms (depression with or without suicidal tendency). Abnormal involuntary movements or dyskinesias, delirium, hallucinations (elderly). Slight elevation of liver enzymes, leucopenia and thrombocytopenia.
Adverse Drug Reactions
Severe postural hypotension in elderly.
Interactions
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.
