Rytary (carbidopa/levodopa) is a prescription drug that’s used to treat Parkinson’s disease and certain types of parkinsonism. Rytary can cause side effects that range from mild to serious. Examples include nausea and headache.

Specifically, Rytary is used in adults to treat:

The active ingredients in Rytary are carbidopa and levodopa. The drug comes as an extended-release oral capsule. (“Extended release” means the drug is released into your body slowly over a period of time.)

Keep reading to learn about the common, mild, and serious side effects that Rytary can cause. For a general overview of the drug, including details about its uses, see this article.

Some people may experience mild to serious side effects during their Rytary treatment. Examples of the drug’s commonly reported side effects include:

  • nausea
  • dizziness
  • headache
  • trouble sleeping
  • unusual dreams

The following sections include more side effects of Rytary. Each person’s experience with side effects may differ.

Mild side effects have been reported with Rytary. These include:

In most cases, these side effects should be temporary. And some may be managed easily. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop taking Rytary unless your doctor recommends it.

Rytary may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

Allergic reaction

For some people, Rytary can cause an allergic reaction. But it’s not clear whether this side effect occurred in the drug’s studies.

In general, symptoms of allergic reaction can be mild or serious. You can learn more about possible symptoms in this article.

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep taking Rytary.

If you have symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911 right away. Or call your local emergency number. These symptoms could be life threatening and require immediate medical care.

Your doctor can confirm whether you’ve had a serious allergic reaction to Rytary. If so, they may have you switch to a different treatment.

Serious side effects have been reported with Rytary. Some are more common, and others are rare. Examples of both include:

Suicidal thoughts or behavior was not reported in studies of the drug. But it has been reported in people after the drug was approved for use.

You can learn more about the following serious side effects in the “Side effects explained” section below:

  • orthostatic hypotension
  • falling asleep during daily activities
  • compulsive behavior

If you develop serious side effects while taking Rytary, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911. Or call your local emergency number.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Rytary, visit MedWatch.

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you are not in the same household, stay on the phone with them until help arrives.

Get answers to some frequently asked questions about Rytary’s side effects.

Are there long-term side effects with Rytary?

It’s possible. Long-term side effects include those that may start at any time you’re taking a drug, even if you’ve taken it for a long time. They also include side effects that may not go away even after you stop taking the drug.

Examples of long-term side effects reported in Rytary’s studies include:

Involuntary movement may occur if you take Rytary for a long time. Compulsive behavior may last for a while after you stop taking the drug.

Talk with your doctor to learn more about how long some side effects of Rytary may last.

How do side effects of Rytary and clonazepam compare?

Rytary and clonazepam are used for different medical purposes. Rytary is prescribed to treat Parkinson’s disease and certain types of parkinsonism. Clonazepam is prescribed to treat panic disorder and certain types of seizure.

Each drug also contains different active ingredients and belongs to a different class of drugs. So they work differently and cause different side effects.

  • Rytary: contains the active drugs carbidopa and levodopa
    • Carbidopa belongs to a drug class called decarboxylase inhibitors.
    • Levodopa belongs to a drug class called central nervous system agents.
  • Clonazepam: belongs to a drug class called benzodiazepines

To learn more about how the side effects of Rytary and clonazepam compare, talk with your doctor or pharmacist.

Are side effects from too much Rytary possible?

Taking too much Rytary can cause harmful side effects. These include:

Due to these risks, it’s important to take Rytary exactly as prescribed. If you accidentally take too much Rytary, call your doctor or pharmacist right away. Or call America’s Poison Centers at 800-222-1222.

To learn more about side effects from taking too much Rytary, talk with your doctor or pharmacist.

Learn more about some of the side effects Rytary may cause.

Orthostatic hypotension

Orthostatic hypotension was one of the more common side effects reported in studies of Rytary. Orthostatic hypotension is a sudden drop in blood pressure that occurs when you rise from a seated position. This can make you feel dizzy and lightheaded, which may lead to falls.

Orthostatic hypotension also may cause other symptoms such as:

  • blurry vision
  • nausea
  • leg buckling
  • weakness
  • confusion

What might help

If you have symptoms of orthostatic hypotension during Rytary treatment, talk with your doctor. They can help determine whether Rytary is the cause. If it is, they may adjust your dose or switch you to another medication if your symptoms are severe. Otherwise, they can discuss ways to help lower your risk of falling or fainting. This includes rising slowly and holding onto something stable while you rise from sitting.

Falling asleep during daily activities

Falling asleep during daily activities, such as driving or eating, occurred in studies of Rytary. In some cases, you may feel drowsiness before this occurs. But you can also fall asleep suddenly without any warning signs. This can occur when you first start Rytary treatment or even after one year of starting the drug.

Some factors can increase the risk of falling asleep when taking this drug. These include a history of sleep problems and taking other drugs that make you feel drowsy.

What might help

Before you start Rytary, tell your doctor if you have a history of sleep disorders. Also tell them if you take other medications that make you drowsy. They may recommend that you avoid driving. They may also recommend avoiding other potentially dangerous activities that could cause harm if you fall asleep.

If you experience excessive daytime sleepiness or episodes of falling asleep during activities, call your doctor right away. They can help determine if you should stop taking Rytary.

Compulsive behavior

Taking Rytary can increase your risk of having intense urges to do new or unusual activities. These include urges to gamble, increased sexual urges, intense urges to spend money, and binge eating. You may find it very difficult to control these urges.

What might help

If you experience urges to participate in unusual or new activities, tell your doctor. They may lower your dose or have you stop taking the medication altogether.

Keeping track of side effects

During your Rytary treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Rytary affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before taking Rytary.

Warnings

Rytary can sometimes cause harmful effects in people who have certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Rytary is a good treatment option for you.

Talk with your doctor about your health history before you take Rytary. Be sure to tell them if any of the following factors apply to you:

  • Peptic ulcer disease: If you’ve had peptic ulcer disease, Rytary can increase your risk of bleeding in your stomach or intestines. Be sure to tell your doctor if you’ve ever had peptic ulcer disease before you start Rytary treatment.
  • Glaucoma: Before starting Rytary, tell your doctor if you have glaucoma. If you have glaucoma, Rytary may increase the pressure inside your eye. This can worsen glaucoma.
  • Previous allergic reaction to Rytary: If you’ve had an allergic reaction to Rytary, taking Rytary again can cause another allergic reaction. Your doctor likely won’t prescribe Rytary if you’ve had an allergic reaction to it in the past.
  • Heart problems: If you have a history of heart problems, including a heart attack, your doctor may monitor you more closely. They may do so when you start or increase your dose of Rytary. This is because Rytary can reduce the blood flow to your heart. In turn, this can cause serious side effects if you have certain heart problems. If you’ve had an irregular heartbeat or heart attack, you’ll start Rytary in the hospital so your doctor can monitor your heart. Be sure to tell your doctor if you have any heart problems before you start Rytary treatment.
  • Taking a nonselective monoamine oxidase inhibitor (MAOI): If you take or have taken a nonselective MAOI in the last 2 weeks, your doctor likely won’t prescribe Rytary. An example is phenelzine (Nardil). Taking these medications together can cause high blood pressure.
  • Psychotic disorder: If you have certain mental health conditions, such as schizophrenia, your doctor likely won’t prescribe Rytary. Some medications for psychotic disorders may make Rytary less effective. Due to this risk, it’s important that your doctor is aware of any mental health conditions you have before you start Rytary.
  • Pregnancy or breastfeeding: It isn’t known whether Rytary is safe if you’re pregnant or breastfeeding. If you are pregnant, breastfeeding, or planning either, talk with your doctor before you start Rytary.
  • Alcohol consumption: Alcohol and Rytary cause many similar side effects. These include nausea, dizziness, headache, and decreased blood pressure. They also slow your ability to think, focus, and react. Drinking alcohol during Rytary treatment can worsen these side effects.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.