levodopa

Drug Name

Generic Name : levodopa

Brand Name: Dopar, Larodopa

Classification: Antiparkinsonian

Pregnancy Category C

Dosage & Route
ADULTS

Individualize dosage. Increase dosage gradually to minimize side effects; titrate dosage carefully to optimize benefits and minimize side effects. Initially, 0.5–1 g PO daily divided into two or more doses given with food. Increase gradually in increments not exceeding 0.75 g/day q 3–7 days as tolerated. Do not exceed 8 g/day, except for exceptional patients. A significant therapeutic response may not be obtained for 6 mo.

PEDIATRIC PATIENTS
  • Safety for use in children < 12 yr not established.
Therapeutic actions
  • Levodopa increases dopamine levels in the brain leading to the stimulation of dopamine receptors.
Indications
  • 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
Adverse effects
  • GI disturbances e.g. nausea, vomiting, anorexia.
  • GI bleeding in peptic ulcer patients.
  • Orthostatic hypotension, cardiac arrhythmias.
  • Psychiatric symptoms (especially the elderly), depression with or without suicidal tendency.
  • Abnormal involuntary movements or dyskinesias, delirium, hallucinations.
  • Slight elevation of liver enzymes, BUN and uric acid.
  • Transient leucopenia and thrombocytopenia.
Contraindications
  • Angle-closure glaucoma; malignant melanoma.
Nursing considerations
Assessment
  • History: Hypersensitivity to levodopa, tartrazine; glaucoma; history of melanoma; suspicious or undiagnosed skin lesions; severe CV or pulmonary disease; occlusive cerebrovascular disease; history of MI with residual arrhythmias; bronchial asthma; renal, hepatic, endocrine disease; history of peptic ulcer; psychiatric disorders; lactation, pregnancy
  • Physical: Weight; T; skin color, lesions; orientation, affect, reflexes, bilateral grip strength, vision examination; P, BP, orthostatic BP, auscultation; R, depth, adventitious sounds; bowel sounds, normal output, liver evaluation; voiding pattern, normal output, prostate palpation; LFTs, renal function tests; CBC with differential
Interventions
  • WARNING: 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.
Teaching points
  • Take this drug exactly as prescribed.
  • Do not take multivitamin preparations with pyridoxine. These may prevent any therapeutic effect of levodopa. Notify your health care provider if you need vitamins.
  • You may experience these side effects: Drowsiness, dizziness, confusion, blurred vision (avoid driving or engaging in activities that require alertness and visual acuity); nausea (take with meals; eat frequent small meals); dry mouth (suck sugarless lozenges or ice chips); painful or difficult urination (empty bladder before each dose); constipation (maintain adequate fluid intake and exercise regularly, request correctives); dark sweat or urine (not harmful); dizziness or faintness when you get up (change position slowly and use caution when climbing stairs).
  • Report fainting, lightheadedness, dizziness; uncontrollable movements of the face, eyelids, mouth, tongue, neck, arms, hands, or legs; mental changes; irregular heartbeat or palpitations; difficult urination; severe or persistent nausea or vomiting.