Levodopa Side Effects

Medically reviewed by Philip Thornton, DipPharm. Last updated on Nov 21, 2024.

Applies to levodopa: inhalation capsule.

Precautions

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.

Do not take this medicine if you are using or have used a monoamine oxidase (MAO) inhibitor (eg, phenelzine, tranylcypromine, Nardil®, Parnate®) within the past 2 weeks.

Do not stop using this medicine without first checking with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping completely.

This medicine may cause dizziness, drowsiness, trouble in controlling movements, or even cause you to fall asleep without warning. Do not drive or do anything else that could be dangerous until you know how this medicine affects you. Stand or sit up slowly if you feel lightheaded or dizzy.

This medicine may add to the effects of alcohol and other central nervous system (CNS) depressants (medicines that make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicines for hay fever, other allergies, or colds, sedatives, tranquilizers, or sleeping medicines, prescription pain medicines or narcotics, medicines for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics. Check with your doctor before taking any CNS depressants while you are using this medicine.

Some people who have used this medicine had unusual changes in their behavior. Talk with your doctor right away if you start having unusual urges, such as gambling urges, binge or compulsive eating, compulsive shopping, or sexual urges while using this medicine.

This medicine may increase your risk for breathing problems (eg, bronchospasm), especially if you have a lung disease (eg, asthma, COPD). Check with your doctor right away if you have a cough, difficulty or noisy breathing, or tightness in the chest.

This medicine might cause your saliva, sweat, or urine to become dark in color. This is nothing to worry about, but it could stain your clothes.

Before you have any medical tests, tell the medical doctor in charge that you are using this medicine. The results of some tests may be affected by this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Serious side effects of levodopa

Along with its needed effects, levodopa may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking levodopa:

Other side effects of levodopa

Some side effects of levodopa may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to levodopa: compounding powder, inhalation capsule, oral capsule, oral tablet.

General adverse events

The more commonly occurring adverse reactions have included cough, nausea, upper respiratory tract infection, and discolored sputum.^[Ref]

Respiratory

• Very common (10% or more): Cough (15%)
• Common (1% to 10%): Discolored sputum, nasal discharge discoloration, oropharyngeal pain, upper respiratory tract infection, nasopharyngitis, bronchitis/pneumonia

In a crossover clinical study in subjects with mild or moderate asthma on a stable regimen of asthma medication (n=25), patients received orally inhaled drug 84 mg every 4 hours for a total of 3 doses and placebo. Cough was reported by 60% of subjects following drug administration compared with 0% following placebo. Ten subjects (40%) had temporary FEV1 reductions from baseline (between 15% and 59%), and 4 of these subjects also had a reduction in FEV1 following placebo. Subjects with a reduction in FEV1 remained asymptomatic and did not require rescue treatment.

Nervous system

• Common (1% to 10%): Dyskinesia, headache
• Frequency not reported: Falling asleep during activities of daily living, somnolence

Gastrointestinal

• Common (1% to 10%): Nausea, vomiting

Psychiatric

• Common (1% to 10%): Insomnia
• Frequency not reported: Hallucinations

During clinical trials, hallucinations were reported in less than 2% of patients receiving orally inhaled levodopa.

Cardiovascular

• Common (1% to 10%): Chest discomfort, orthostatic hypotension/blood pressure decreased

Hepatic

• Common (1% to 10%): Increased blood bilirubin

Dermatologic

• Common (1% to 10%): Laceration, skin abrasion

Dermatologic

Musculoskeletal

• Common (1% to 10%): Extremity pain

Hematologic

• Common (1% to 10%): Decreased red blood cell count

Other

• Common (1% to 10%): Fall

Fever, altered consciousness, autonomic dysfunction and muscle rigidity are the hallmarks of the neuroleptic malignant syndrome. The neuroleptic malignant syndrome (NMS) is associated with a case fatality rate of about 20%. If withdrawal of dopaminergic therapy is suspected as the cause of NMS, dopaminergic therapy should be restarted. If a neuroleptic agent is suspected as the cause, the neuroleptic agent should be immediately discontinued. For patients with NMS suspected to be due to neuroleptic therapy, consideration should be given to dantrolene (or bromocriptine) administration. Intensive monitoring and supportive care are indicated for all patients with NMS.

See also:

Frequently asked questions

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Further information

Levodopa side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer