Carbidopa (Lodosyn): Uses, Side Effects, Interactions, Pictures, Warnings & Dosing

Uses

What is carbidopa used for?

Carbidopa is commonly used to treat Parkinson’s disease, a condition that affects the part of your brain that controls your movements. It may also be used to treat conditions with symptoms similar to Parkinson’s disease (called parkinsonism).

Carbidopa may also be used for other conditions as determined by your healthcare provider.

How does carbidopa work (mechanism of action)?

In people with Parkinson's disease, the brain does not have enough of a chemical called dopamine, which helps control movement. This makes it hard for people to move their bodies the way they want to.

Carbidopa and levodopa are medicines that work together to help people with Parkinson's disease.

Levodopa is a medicine that turns into dopamine in the brain. When levodopa is used by itself, it gets broken down too quickly, before it can reach the brain. Carbidopa works to block the breakdown of levodopa so that more dopamine can get to the brain. This helps people with Parkinson's disease move more easily.

How is carbidopa supplied (dosage forms)?

Brands and other names

Lodosyn

Dosage forms and strengths

25 mg oral tablets

How should I store carbidopa?

Carbidopa should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place.

Side Effects

What are the most common side effects of carbidopa?

The most common side effects of carbidopa used in combination with levodopa are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

Uncontrollable, involuntary movements (see below)
Nausea

There may be other side effects of carbidopa that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of carbidopa?

While less common, the most serious side effects of carbidopa used in combination with levodopa are described below, along with what to do if they happen.

Severe Allergic Reactions. Carbidopa may cause allergic reactions, which can be serious. Stop taking carbidopa and get help right away if you have any of the following symptoms of a serious allergic reaction.

Breathing problems or wheezing
Racing heart
Fever or general ill feeling
Swollen lymph nodes
Swelling of the face, lips, mouth, tongue, or throat
Trouble swallowing or throat tightness
Itching, skin rash, or pale red bumps on the skin called hives
Nausea or vomiting
Dizziness, feeling lightheaded, or fainting
Stomach cramps
Joint pain

Sleepiness. Carbidopa (in combination with other medicine for Parkinson's disease) can make you sleepy, sometimes very suddenly and without warning signs (also called a "sleep attack"). Do not drive or do other activities that require alertness or coordination until you know how this medicine affects you. Tell your healthcare provider if you feel sleepy or drowsy while taking this medicine.

Unusual or Compulsive Behaviors. Carbidopa (in combination with other medicine for Parkinson's disease) can cause some people to have strong unusual and uncontrolled urges (compulsions), including gambling, sex, shopping, or eating. Talk to your healthcare provider right away if you or someone you know notices that you have new or worsening strong urges or behaviors.

Hallucinations or Psychotic-like Behaviors. Carbidopa (in combination with other medicine for Parkinson's disease) may cause hallucinations or psychotic-like behaviors. Talk to your healthcare provider right away if you or someone you know notices that you have any of the following symptoms.

Hearing, seeing, smelling, tasting, or otherwise perceiving things that others do not
Delusional thoughts, such as false beliefs that you are being controlled
Disorganized thoughts, such as jumping between topics or having a hard time focusing
Sudden decline in self-care, such as personal hygiene or academic/work performance
Aggressive behavior

Uncontrollable, Involuntary Movements (Dyskinesias). Carbidopa (in combination with other medicine for Parkinson's disease) may cause involuntary movement problems, including shakiness, stiffness, or jerkiness. Call your healthcare provider right away if you develop any unusual or uncontrolled movements or if they get worse.

Depression and Suicidal Thoughts. Carbidopa (in combination with other medicine for Parkinson's disease) may cause depression in a small number of people. If you having thoughts of harming yourself, call 911 or call or text 988, the Suicide & Crisis Lifeline. Call your healthcare provider right away if you have any of the following symptoms.

New or increased thoughts of suicide or death
Suicide attempt
New or increased feelings of anxiety, depression, or other unusual changes in mood or behavior

Warnings & Precautions

Who should not use carbidopa?

Allergies to Ingredients. People who are allergic to any of the following should not take carbidopa.

Carbidopa
Lodosyn
Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific carbidopa products they stock.

Drug Interactions. Carbidopa should not be taken while you are using or if you have recently used certain other medicines. Before taking carbidopa, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Glaucoma. People with narrow-angle glaucoma should not receive this medicine.

What should I know about carbidopa before using it?

Do not take carbidopa unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share carbidopa with other people, even if they have the same condition as you. It may harm them.

Keep carbidopa out of the reach of children.

Do not stop taking carbidopa without talking to your healthcare provider. Stopping too quickly may cause serious side effects. Call your healthcare provider right away if you have any of the following symptoms.

High fever
Muscle stiffness or rigidity, where it is hard to move
Changes in your breathing or heart rate
Increased sweating
Confusion

You may notice a dark color in your saliva, sputum, urine, or sweat. This is a common side effect and is not believed to be harmful. However, your clothes might get stained.

Carbidopa (in combination with other medicine for Parkinson's disease) may cause you to feel sleepy, especially if you already have conditions that can make you drowsy. This medicine may also cause dizziness, especially when you stand up quickly after lying or sitting down. If this occurs, get up slowly after sitting or lying down. Do not drive or do other activities that require alertness or coordination until you know how this medicine affects you.

What should I tell my healthcare provider before using carbidopa?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if carbidopa is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

Mental health or behavior problems, including depression or any psychotic disorder (such as schizophrenia or delusional disorder)
Sleep problems
Any other movement disorders
Skin problems, such as skin cancer
Eye problems, such as glaucoma
Low blood pressure or feeling faint or dizzy, especially when standing up from a seated or lying position
Unusual urges, such as gambling, binge eating, compulsive shopping, or increased sex drive

Pregnancy. It is not known if or how carbidopa could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant. Your healthcare provider will advise you if you should take carbidopa while you are pregnant or trying to get pregnant.

Breastfeeding. It is not known if carbidopa passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should stop breastfeeding or stop carbidopa.

Interactions

Does carbidopa interact with foods or drinks?

Carbidopa is used with levodopa. High-protein foods may affect how well your body absorbs levodopa and decrease how well levodopa works. If you change the amount of protein in your diet, tell your healthcare provider.

It is unknown if drinking alcohol will affect carbidopa. However, the risk of drowsiness, sleepiness, and/or dizziness may be increased if you drink alcohol while taking carbidopa in combination with other medicine for Parkinson's disease.

Does carbidopa interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking carbidopa (in combination with other medicine for Parkinson's disease).

A nonselective monoamine oxidase inhibitor (MAOI) within the past 2 weeks, such as phenelzine (Nardil), tranylcypromine (Parnate), or isocarboxazid (Marplan), which is a medicine usually used for depression
A selective monoamine oxidase B (MAO-B) inhibitor, such as rasagiline or selegiline, which is a medicine usually used for depression or Parkinson’s disease
An antipsychotic, such as haloperidol, chlorpromazine, thioridazine, fluphenazine, or risperidone, which is a medicine for certain mental health conditions
A medicine for high blood pressure
A tricyclic antidepressant, such as amitriptyline, nortriptyline, or protriptyline, even if it is not used for depression
Isoniazid, which is a medicine used to treat an infection called tuberculosis
Phenytoin (Dilantin, Phenytek, and others), which is a medicine to control seizures
Papaverine, which is a medicine used for various blood flow problems, including chest pain
Iron supplements or other products (such as multivitamins) that contain iron
Metoclopramide (Reglan and others), which is a medicine for certain stomach problems
Any other medicine that causes dizziness and sleepiness, such as prescription pain medicines, sleep medicines, and medicines for anxiety

This may not be a complete list of medicines that can interact with carbidopa. Always check with your healthcare provider.

Does Carbidopa (Lodosyn) interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much carbidopa?

If you or someone else has used too much carbidopa, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of carbidopa?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.