Carbidopa/levodopa 25-100mg Tabs

Levodopa, a precursor of dopamine, crosses the blood-brain barrier and is converted to dopamine in the brain by DOPA decarboxylase, replenishing dopamine levels in the substantia nigra. Carbidopa, an aromatic L-amino acid decarboxylase inhibitor, does not cross the blood-brain barrier and inhibits the peripheral conversion of levodopa to dopamine, thereby increasing the amount of levodopa available to the brain and reducing peripheral side effects (e.g., nausea, vomiting).

Serious Side Effects: Seek Medical Help Immediately

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention right away:

Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high or low blood pressure, including:
+ Severe headache or dizziness
+ Passing out
+ Changes in eyesight
New or worsening behavioral or mood changes, such as:
+ Depression
+ Thoughts of suicide
Hallucinations (seeing or hearing things that are not there)
Confusion
Strong, uncontrollable urges (e.g., eating, gambling, sex, or spending money)
A skin lump or growth
Changes in the color or size of a mole
New or worsening trouble controlling body movements
Eyelid twitching
Muscle twitching
Stomach pain
Black, tarry, or bloody stools
Vomiting blood or coffee ground-like material
Chest pain or pressure
Fast or abnormal heartbeat
Fever, chills, or sore throat
Unexplained bruising or bleeding
Feeling extremely tired or weak
Dark urine or yellow skin and eyes
Changes in eyesight, eye pain, or severe eye irritation
Shortness of breath
Sudden sleepiness, especially during activities like driving, eating, or talking

If you experience sudden sleepiness, do not drive or engage in activities that require alertness. Contact your doctor immediately if you experience this side effect or feel extremely sleepy.

Other Possible Side Effects

Like all medications, this drug can cause side effects. Many people may not experience any side effects or may only have mild ones. If you notice any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:

Bad dreams
Constipation
Dizziness or sleepiness
Dry mouth
Headache
Trouble sleeping
Some products may cause a dark red, brown, or black color to appear in your saliva, urine, or sweat (this is harmless but may discolor your clothes)
* Upset stomach or vomiting

This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following:

Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Describe the allergic reaction you experienced, including the symptoms that occurred.
Certain health conditions, including:
+ Glaucoma
+ Skin lumps or growths
+ A history of skin cancer
Medications you are currently taking, such as:
+ Reserpine or tetrabenazine
+ Linezolid or methylene blue
If you have taken specific medications for depression or Parkinson's disease within the last 14 days, including:
+ Isocarboxazid
+ Phenelzine
+ Tranylcypromine
+ Selegiline
+ Rasagiline (note: taking this medication with these drugs can lead to very high blood pressure)
* If you are taking another medication that contains the same active ingredient as this drug

This list is not exhaustive, and it is crucial to inform your doctor and pharmacist about all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, as well as any health problems you have. This will help ensure your safety while taking this medication. Never start, stop, or change the dose of any medication without first consulting your doctor.

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. This will help ensure your safety and prevent any potential interactions with other treatments.

To minimize the risk of accidents, avoid driving and engaging in activities that require alertness until you understand how this medication affects you. When changing positions, such as standing up from a sitting or lying down position, do so slowly to reduce the likelihood of dizziness or fainting. Be cautious when navigating stairs to prevent falls.

This medication may interfere with certain laboratory tests, so it is crucial to notify all your healthcare providers and laboratory personnel that you are taking this drug. Adhere to your doctor's recommendations for regular blood tests and eye exams to monitor your condition.

If you have diabetes (high blood sugar), consult with your doctor to determine the most suitable glucose tests for you to use. Additionally, be aware that the effectiveness of this medication may decrease as the time approaches for your next dose. If you experience a decrease in the medication's effectiveness and it bothers you, inform your doctor.

Before consuming alcohol, using marijuana or other cannabis products, or taking prescription or over-the-counter medications that may cause drowsiness, discuss the potential risks with your doctor. Individuals with Parkinson's disease may have an increased risk of developing a type of skin cancer called melanoma, although it is unclear if this medication contributes to this risk. To be cautious, schedule regular skin exams with your doctor while taking this medication.

Do not abruptly stop taking this medication or reduce your dosage without consulting your doctor, as this may lead to severe side effects, including fever, muscle cramps or stiffness, dizziness, severe headache, confusion, changes in thinking, abnormal heartbeat, or excessive sweating. If you experience any of these symptoms, contact your doctor immediately.

If you are pregnant, plan to become pregnant, or are breastfeeding, inform your doctor to discuss the potential benefits and risks of this medication to both you and your baby.

• Non-selective Monoamine Oxidase Inhibitors (MAOIs) (e.g., phenelzine, tranylcypromine) - risk of hypertensive crisis. Must be discontinued at least 2 weeks prior to initiating carbidopa/levodopa.

• Antipsychotics (e.g., haloperidol, chlorpromazine, risperidone, olanzapine) - may antagonize the effects of levodopa due to dopamine receptor blockade, worsening Parkinsonian symptoms.
• Iron salts (ferrous sulfate, gluconate) - can chelate levodopa, reducing its absorption. Separate administration by at least 2 hours.
• Metoclopramide - may antagonize the effects of levodopa and increase risk of extrapyramidal symptoms.
• Pyridoxine (Vitamin B6) - large doses (e.g., >10-25 mg) can reverse the effects of levodopa if carbidopa is not present in sufficient amounts (less significant with carbidopa/levodopa combination).

• Antihypertensives - additive hypotensive effects, especially orthostatic hypotension.
• Tricyclic Antidepressants (TCAs) - may rarely increase the risk of dyskinesias and orthostatic hypotension. Monitor blood pressure.
• Dopamine D2 receptor antagonists (e.g., domperidone) - can reduce the efficacy of levodopa.
• High-protein diet - reduces levodopa absorption and transport to the brain.

• Not available

• Dyskinesias (involuntary movements)
• Hallucinations or delusions
• Orthostatic hypotension (dizziness upon standing)
• Nausea or vomiting
• Sudden onset of sleep or excessive daytime sleepiness
• Impulse control disorders (e.g., pathological gambling, hypersexuality, compulsive shopping, binge eating)
• Depression or mood changes
• Anxiety
• Confusion

Category C. Use during pregnancy only if the potential benefit justifies the potential risk to the fetus. Levodopa has been shown to be teratogenic in animals at high doses.

L3 (Moderate Risk). Levodopa is excreted into breast milk. Carbidopa is also likely excreted. May suppress lactation. Weigh the benefits of breastfeeding against the potential risks to the infant.

Not indicated for Parkinson's disease in pediatric patients. Used off-label for certain conditions like Dopa-responsive dystonia, with highly individualized dosing and close monitoring.

Elderly patients may be more sensitive to the central nervous system side effects (e.g., hallucinations, confusion, dyskinesias) and orthostatic hypotension. Initiate with lower doses and titrate slowly. Close monitoring is essential.

• Carbidopa/levodopa is the most effective medication for the motor symptoms of Parkinson's disease, particularly bradykinesia and rigidity.
• The 'wearing-off' phenomenon (return of symptoms before the next dose) and 'on-off' fluctuations are common complications with long-term use. Strategies include more frequent dosing, extended-release formulations, or adjunctive therapies.
• High-protein meals can interfere with levodopa absorption and transport across the blood-brain barrier. Advise patients to take the medication 30-60 minutes before or 1-2 hours after protein-rich meals, or to distribute protein intake throughout the day.
• Sudden withdrawal can lead to a neuroleptic malignant syndrome-like syndrome (fever, rigidity, altered mental status, autonomic instability). Taper slowly if discontinuation is necessary.
• Impulse control disorders (e.g., pathological gambling, hypersexuality, compulsive shopping, binge eating) can occur. Screen patients for these behaviors.
• Non-motor symptoms (e.g., sleep disturbances, depression, anxiety, cognitive impairment) are common in Parkinson's disease and may require separate management.
• Darkening of urine, sweat, or saliva can occur due to levodopa metabolites; this is harmless but can stain clothing.

• Dopamine agonists (e.g., pramipexole, ropinirole, rotigotine)
• MAO-B inhibitors (e.g., selegiline, rasagiline, safinamide)
• COMT inhibitors (e.g., entacapone, opicapone, tolcapone - used as adjuncts to carbidopa/levodopa)
• Amantadine (for dyskinesia and mild symptoms)
• Anticholinergics (e.g., benztropine, trihexyphenidyl - for tremor, less common due to side effects)
• Adenosine A2A receptor antagonists (e.g., istradefylline - for 'off' episodes)

If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.