Pronunciation: crex-ont
Generic name: carbidopa and levodopa
Dosage form: extended-release capsule
Drug class: Dopaminergic antiparkinsonism agents

Medically reviewed by Carmen Pope, BPharm. Last updated on Aug 12, 2024.

What is Crexont?

Crexont (carbidopa and levodopa) is an extended-release capsule that may be used to treat symptoms of Parkinson's disease, such as stiffness or tremors. It may also be used to treat Parkinson's symptoms caused by carbon monoxide poisoning or manganese intoxication in adults.

Crexont contains both immediate-release granules and extended-release pellets within each capsule which helps improve the time each capsule is effective for, reducing OFF time (OFF time is when Parkinson's symptoms return between medication doses). Research has shown Crexont was associated with about half an hour more of “good on” time per day compared with immediate-release formulations.

The components of Crexont, carbidopa, and levodopa, work together to provide the brain with more dopamine. Levodopa is a precursor to dopamine and readily crosses the blood-brain barrier where it is converted into dopamine. Carbidopa prevents the breakdown of levodopa in the bloodstream so that more is available to reach the brain. Increasing the supply of dopamine in the brain (a substance that helps manage body movements and coordination) is thought to be the mechanism of action of Crexont for Parkinson's disease and Parkinson-like tremors.

Crexont gained FDA approval on August 7, 2024. The combination of carbidopa and levodopa for Parkinson's disease was first approved on May 2, 1975, under the brand Sinemet.

Crexont side effects

The most common side effects of Crexont are nausea and anxiety. Other side effects may include:

• jerky or twisting muscle movements

• headache, dizziness

• low blood pressure (feeling light-headed)

• sleep problems, strange dreams

• dry mouth

• muscle contractions

• nausea, vomiting, or constipation.

Serious side effects and warnings

Crexont may cause the following serious side effects.

Falling asleep during activities of daily living and sleepiness. Certain side effects of Crexont, such as sleepiness and dizziness may affect some patients’ ability to drive and operate machinery safely

Suicidal thoughts and behavior. Tell your healthcare provider immediately if you or the person you are caring for experiences suicidal thoughts or behavior while they are taking Crexont.

Hallucinations have been reported with levodopa products, such as Crexont.

Impulse control disorders. Crexont may affect your ability to control your impulses and you may experience intense urges to gamble, increased sexual urges, or other intense urges that you may be unable to control.

Movement disorders that may appear as uncontrolled shakes, tics, or tremors (dyskinesias) have been reported with carbidopa/levodopa products such as Crexont. Tell your healthcare provider right away if you develop any abnormal involuntary movements or your current Parkison’s tremors get worse during treatment with Crexont.

Crexont may cause a drop in blood pressure when going from sitting to standing which may cause symptoms such as dizziness, nausea, fainting, and sweating. Rise slowly after sitting or lying down, especially if they have been doing so for a long time.

Get emergency medical help if you have signs of an allergic reaction to Sinemet: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• uncontrolled muscle movements in your face (chewing, lip smacking, frowning, tongue movement, blinking or eye movement)

• worsening of tremors (uncontrolled shaking)

• severe or ongoing vomiting or diarrhea

• confusion, hallucinations, unusual changes in mood or behavior

• depression or suicidal thoughts

• severe nervous system reaction - very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out.

This is not a complete list of side effects. To report suspected side effects, contact Amneal Pharmaceuticals at 1-877-835-5472 or FDA at 1- 800-FDA-1088 or www.fda.gov/medwatch.

Before taking

You should not use Crexont if you:

• are allergic to carbidopa or levodopa, Crexont, or any of the inactive ingredients in the capsules
• have narrow-angle glaucoma
• have used an MAO inhibitor in the past 14 days because a dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, tranylcypromine, and others.

Before taking Crexont, tell your doctor about all your medical conditions including if you have ever had:

• heart disease, high blood pressure, or heart attack
• liver or kidney disease
• an endocrine (hormonal) disorder
• asthma, chronic obstructive pulmonary disease (COPD), or other breathing disorder
• a stomach or intestinal ulcer
• open-angle glaucoma
• depression, mental illness, or psychosis.

People with Parkinson's disease may have a higher risk of skin cancer (melanoma). Talk to your doctor about this risk and what skin symptoms to watch for.

Tell your doctor if you are pregnant, intend to become pregnant, or are breastfeeding.

How should I take Crexont?

Crexont is usually taken two to three times daily with or without food.

• The dosage depends on whether the patient has previously been on levodopa or not.

Do not chew, divide, or crush the capsules.

Avoid alcohol while taking Crexont.

Do not stop Crexont suddenly. Talk to your healthcare provider about discontinuing it slowly if you wish to stop taking it. Exceptionally high fevers (hyperpyrexia) and confusion have been associated with sudden discontinuation of carbidopa/levodopa products such as Crexont.

Crexont dosing information

Levodopa-naïve patients

• The starting dose is Crexont 35/140 twice daily for the first 3 days.
  • On the fourth day of treatment, dosage may be increased gradually as needed.

Patients converting from immediate-release carbidopa/levodopa

See the Crexont Prescribing Information for full instructions. The dosing table below gives guidance.

• Dosages are not substitutable on a 1:1 basis.
• The maximum recommended daily dosage of Crexont is carbidopa 525 mg / levodopa 2100 mg.

Related/similar drugs

ropinirole, benztropine, pramipexole, amantadine, Exelon, Gocovri

What should I avoid while taking Crexont?

Avoid driving or hazardous activity until you know how Crexont will affect you. Your reactions could be impaired. Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Avoid taking iron supplements or eating a diet high in protein. These things can make it harder for your body to digest and absorb Crexont. Talk with your doctor or dietitian about the best foods to eat or avoid.

What other drugs will affect Crexont?

Other drugs may affect Crexont, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using. Especially tell your doctor if you take

• Iron supplements
• Antipsychotic medications such as benztropine or haloperidol
• CNS depressants, such as opioids or benzodiazepines because of the possible additive sedative effects

Also, tell your healthcare provider if you have taken an MAO inhibitor in the past 14 days because a dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, tranylcypromine, and others.

This is not a complete list of interactions. See the Crexont Package Insert for a full list.

Storage

Store at room temperature in a tightly closed container, protected from light and moisture.

Ingredients

Active ingredients: carbidopa and levodopa

Inactive ingredients: amino methacrylate copolymer, cellulose acetate, copovidone, croscarmellose sodium, magnesium stearate, mannitol, methacrylic acid, and methyl methacrylate copolymer, microcrystalline cellulose, povidone, sodium lauryl sulfate, talc, and triethyl citrate.

Capsule shell

• 35 mg/140 mg capsule shell contains D&C yellow #10, gelatin, Red Iron Oxide, and titanium dioxide.
• 52.5 mg/210 mg capsule shell contains FD&C Blue #1, gelatin, titanium dioxide, and yellow iron oxide.
• 70 mg/280 mg capsule shell contains FD&C Blue #1, FD&C Red #3, gelatin, and titanium dioxide.
• 87.5 mg/350 mg capsule shell contains gelatin, Red Iron Oxide, titanium dioxide, and yellow iron oxide.

Imprinting ink

The black imprinting ink contains ammonium hydroxide, ethanol, ferrosoferric oxide/black iron oxide, isopropyl alcohol, n-butyl alcohol, propylene glycol, and shellac glaze.

The white imprinting ink contains ethanol, isopropyl alcohol, n-butyl alcohol, povidone, propylene glycol, shellac glaze, sodium hydroxide, and titanium dioxide.

What strengths of Crexont are available?

Crexont extended-release capsules are available in 4 strengths:

• carbidopa 35 mg/ levodopa 140 mg
• carbidopa 52.5 mg/ levodopa 210 mg
• carbidopa 70 mg/ levodopa 280 mg
• carbidopa 87.5 mg/ levodopa 350 mg

Who makes Crexont?

Amneal Specialty, a division of Amneal Pharmaceuticals LLC manufactures Crexont.

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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