Brand Name: Dopar, Larodopa
Pregnancy Category C
Drug class: Antiparkinsonian agent
Biochemical precursor of the neurotransmitter dopamine, which is deficient in the basal ganglia of parkinsonism patients; unlike dopamine, levodopa penetrates the blood–brain barrier. It is transformed in the brain to dopamine; thus, levodopa is a form of replacement therapy. It is efficacious for 2–5 yr in relieving the symptoms of parkinsonism but not drug-induced extrapyramidal disorders.
• Treatment of parkinsonism (postencephalitic, arteriosclerotic, and idiopathic types) and symptomatic parkinsonism, following injury to the nervous system by carbon monoxide or manganese intoxication
• Given with carbidopa (Lodosyn; fixed combinations, Sinemet), an enzyme inhibitor that decreases the activity of dopa decarboxylase in the periphery, thus reducing blood levels of levodopa and decreasing the intensity and incidence of many of the adverse effects of levodopa
• Unlabeled use: relief of herpes zoster (shingles) pain; restless leg syndrome
• Contraindicated with hypersensitivity to levodopa; allergy to tartrazine (marketed as Dopar); glaucoma, especially angle-closure glaucoma; history of melanoma; suspicious or undiagnosed skin lesions; lactation.
Adventitious movement (eg, dystonic movements), ataxia, increased hand tremor, headache, dizziness, numbness, weakness and faintness, bruxism, confusion, insomnia, nightmares, hallucinations and delusions, agitation and anxiety, malaise, fatigue, euphoria, mental changes (including paranoid ideation), psychotic episodes, depression with or without suicidal tendencies, dementia, bradykinesia (“on-off” phenomenon), muscle twitching and blepharospasm, diplopia, blurred vision, dilated pupils
Cardiac irregularities, palpitations, orthostatic hypotension
Flushing, hot flashes, increased sweating, rash
Anorexia, nausea, vomiting, abdominal pain or distress, dry mouth, dysphagia, dysgeusia, bitter taste, sialorrhea, trismus, burning sensation of the tongue, diarrhea, constipation, flatulence, weight change, upper GI hemorrhage in patients with history of peptic ulcer
Urinary retention, urinary incontinence
Leukopenia, anemia, elevated BUN, AST, ALT, LDH, bilirubin, alkaline phosphatase, protein-bound iodine
Bizarre breathing patterns
• Increased therapeutic effects and possible hypertensive crisis with MAOIs; withdraw MAOIs at least 14 days before starting levodopa therapy
• Decreased efficacy with pyridoxine (vitamin B6), phenytoin, papaverine, TCAs
• Arrange to decrease dosage if therapy is interrupted; observe for the development of suicidal tendencies.
• Give with meals if GI upset occurs.
• Ensure that patient voids before receiving dose if urinary retention is a problem.
• Monitor hepatic, renal, hematopoietic, and CV function.
• For patients who take multivitamins provide Larobec, a preparation without pyridoxine.