Antiparkinson Medication Overview

Drug Class

• Antiparkinson medication, functioning as a dopamine replacement.

Therapeutic Effects/Uses

• Primarily used to treat parkinsonism.
• Alleviates symptoms such as tremors and rigidity.

Mode of Action

• Levodopa is transmitted to brain cells where it converts to dopamine.
• Carbidopa prevents levodopa from converting to dopamine in the intestine and peripheral tissues, allowing more levodopa to reach the brain.

Contraindications

• Not recommended for individuals with narrow-angle glaucoma, severe cardiac, renal, or hepatic diseases.
• Cautions include peptic ulcer disease, psychiatric disorders, seizure disorders, and suicidal ideation.

Drug Interactions

• Risk of hypertensive crisis when combined with MAO inhibitors (MAOIs).
• Anticholinergics and antipsychotics can decrease the effectiveness of levodopa.

Lab Interactions

• May elevate levels of BUN, AST, ALT, ALP, and LDH in laboratory tests.

Side Effects

• Common: Anorexia, nausea, vomiting, dysphagia, fatigue, dizziness, headache, dry mouth, bitter taste, twitching, blurred vision, insomnia, and dark urine.

Life-Threatening and Other Adverse Reactions

• Serious risks include agranulocytosis, hemolytic anemia, thrombocytopenia, cardiac dysrhythmias, and neuroleptic malignant syndrome.
• Other adverse effects can involve involuntary movements, palpitations, orthostatic hypotension, urinary retention, priapism, psychosis, severe depression with suicidal ideation, and hallucinations.

Abrupt Discontinuation

• Patients should avoid stopping medication abruptly to prevent rebound parkinsonism, which can lead to a return of symptoms.

Urine Color Change

• Urine discoloration is a harmless side effect, darkening when exposed to air; perspiration may also darken, which can stain clothes.

Diet Recommendation

• Taking the medication with food can reduce gastrointestinal upset but may slow the absorption rate of the drug.

PO Onset

• Oral administration results in an onset of action within 15 minutes.