Levodopa

Key facts

• Levodopa (combined with carbidopa in products such as Sinemet, and with carbidopa and entacapone in Stalevo) is converted into dopamine in the brain, restoring signals that control movement.
• Tablets are taken several times a day, timed around meals since protein can reduce absorption; the effect can wear off between doses as Parkinson's disease progresses.
• Never stop levodopa suddenly or skip several doses. Abrupt withdrawal can trigger severe muscle rigidity, high fever, and confusion, a rare but life-threatening reaction similar to neuroleptic malignant syndrome.
• Seek urgent care for high fever with severe stiffness, sudden severe confusion, or fainting.

What levodopa treats

Levodopa treats the motor symptoms of Parkinson's disease, tremor, rigidity, slow movement, and impaired balance, and similar symptoms in parkinsonism from other causes.

How levodopa works

After you swallow a tablet, levodopa crosses into the brain, where it is converted into dopamine, restoring the signals that keep muscles moving smoothly. Carbidopa blocks that conversion outside the brain, so more levodopa reaches the brain and nausea is reduced.

Before you take it

• Tell your prescriber about narrow-angle glaucoma, severe heart disease, or a history of melanoma or unevaluated skin lesions, since levodopa is generally avoided in active melanoma.
• Mention any psychiatric condition; levodopa can worsen hallucinations or psychosis in susceptible people.
• Do not combine levodopa with non-selective MAOI antidepressants; the combination can cause a dangerous rise in blood pressure.
• Report any history of sudden sleep episodes or impulse-control problems before starting.

Side effects

Common effects include nausea, light-headedness on standing, dyskinesia (small involuntary movements), dry mouth, and vivid dreams.

Stop and seek urgent medical care for any of these:

• High fever with severe muscle stiffness and confusion after stopping or missing doses.
• Hallucinations or severe confusion.
• Sudden, uncontrollable sleep episodes, particularly while driving.

Safety essentials

• Never stop levodopa abruptly. Your prescriber will taper it gradually, even when switching to another Parkinson's medicine, to avoid a severe fever-and-rigidity reaction.
• Report any new compulsive behavior, such as gambling, shopping, or hypersexuality; these impulse-control changes are a recognized effect of dopamine-boosting medicines.
• Levodopa can cause sudden sleep episodes without warning; be cautious driving or operating machinery until you know how it affects you.
• Avoid non-selective MAOI antidepressants while taking levodopa.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.