Carbidopa 25mg Tablets

Carbidopa is an inhibitor of DOPA decarboxylase, an enzyme responsible for the peripheral metabolism of levodopa to dopamine. When administered with levodopa, carbidopa inhibits peripheral DOPA decarboxylase, thereby reducing the peripheral breakdown of levodopa. This allows more levodopa to cross the blood-brain barrier for conversion to dopamine in the central nervous system, reducing the required levodopa dose and minimizing peripheral side effects (e.g., nausea, vomiting, cardiac arrhythmias) associated with peripheral dopamine formation.

Serious Side Effects: Seek Medical Help Right Away

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 immediately:

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 depression, including:
+ Thoughts of suicide
+ Nervousness
+ Emotional ups and downs
+ Abnormal thinking
+ Anxiety
+ Lack of interest in life
Signs of high or low blood pressure, such as:
+ Severe headache
+ Dizziness
+ Passing out
+ Changes in eyesight
Signs of a urinary tract infection (UTI), including:
+ Blood in the urine
+ Burning or pain while urinating
+ Frequent or urgent need to urinate
+ Fever
+ Lower stomach pain
+ Pelvic pain
Changes in behavior
Hallucinations (seeing or hearing things that are not there)
Strong, uncontrollable urges (such as eating, gambling, sex, or spending money)
Vomiting blood or coffee ground-like material
Black, tarry, or bloody stools
Abnormal burning, numbness, or tingling sensations
Chest pain or pressure
Abnormal heartbeat
Fever, chills, or sore throat
Unexplained bruising or bleeding
Feeling extremely tired or weak
Skin lumps or growths
Changes in mole color or size
Vision changes
New or worsening trouble controlling body movements
Grinding of teeth
Shortness of breath
Swelling
Changes in urine output
Painful erection (lasting more than 4 hours)

Other Possible Side Effects

Like all medications, this drug can cause side effects. Many people experience no side effects or only mild ones. If you notice any of the following side effects or any other unusual symptoms, contact your doctor or seek medical attention:

Dizziness
Drowsiness
Fatigue
Weakness
Headache
Dry mouth
Sleep disturbances
Constipation
Diarrhea
Stomach pain
Upset stomach
Nausea
Vomiting
Decreased appetite
Gas
Heartburn
Hiccups
Changes in taste
Vivid or unusual dreams
Weight changes
Common cold symptoms
Back pain
Arm or leg pain
Muscle cramps
Flushing
Excessive sweating
Hair loss
Hot flashes

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 conditions to ensure safe treatment:

Any allergies you have, including allergies to this medication, its components, or other substances. Be sure to describe the symptoms you experienced.
A diagnosis of glaucoma.
Recent use of certain antidepressant medications, such as isocarboxazid, phenelzine, or tranylcypromine, within the last 14 days. Taking this medication too soon after these drugs can lead to severe high blood pressure.
Current use of linezolid or methylene blue.
* Use of any other medication that contains the same active ingredient as this drug.

Special Considerations for Children:
This medication is not intended for children. Do not administer it to a child.

Additional Important Information:
This list is not exhaustive, and it is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health conditions with your doctor and pharmacist. They will help determine if it is safe to take this medication with your other treatments. Never start, stop, or adjust the dosage of any medication without consulting your doctor first.

Important Information to Share with Your Healthcare Team

Inform all of your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.

Caution with Daily Activities

Until you know how this medication affects you, avoid driving and other tasks that require you to be alert. To minimize the risk of dizziness or fainting, get up slowly from a sitting or lying down position, and be cautious when climbing stairs.

Interactions with Other Substances

Discuss the use of alcohol, marijuana, or other forms of cannabis, as well as prescription or over-the-counter medications that may cause drowsiness, with your doctor before consuming them.

Monitoring and Lab Tests

Follow your doctor's instructions for regular blood work and other laboratory tests. Inform all of your healthcare providers and lab personnel that you are taking this medication, as it may affect certain lab test results. If you have diabetes, consult with your doctor about the best glucose tests to use.

Medication Effects

As the time approaches for your next dose, you may experience a decrease in the medication's effectiveness. If this occurs and bothers you, notify your doctor. You may notice a dark discoloration (red, brown, or black) in your saliva, urine, or sweat, which is harmless but may stain your clothing.

Delayed Onset of Full Effect

It may take several months to experience the full benefits of this medication.

Risk of Sudden Sleepiness

Some individuals have reported falling asleep suddenly during activities like driving, eating, or talking, even if they did not feel drowsy beforehand. This can occur up to 1 year after starting the medication. If you experience sudden sleepiness, do not engage in activities that require alertness, and notify your doctor immediately.

Skin Cancer Risk

People with Parkinson's disease may have an increased risk of developing a type of skin cancer called melanoma. It is unclear if this medication also increases this risk. Regular skin exams are recommended while taking this medication. Discuss any concerns with your doctor.

Pregnancy and Breastfeeding

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

• Non-selective Monoamine Oxidase Inhibitors (MAOIs) (e.g., phenelzine, tranylcypromine): Concomitant use can lead to hypertensive crisis. MAOIs should be discontinued at least 2 weeks prior to initiating carbidopa/levodopa.

• Iron salts (ferrous sulfate, ferrous gluconate): May reduce the bioavailability of levodopa and carbidopa. Separate administration by at least 2 hours.
• Antihypertensive drugs: Postural hypotension may occur; dose adjustment of antihypertensive may be needed.
• Dopamine D2 receptor antagonists (e.g., phenothiazines, butyrophenones, metoclopramide): May antagonize the effects of levodopa/carbidopa.

• Other MAOIs (e.g., selegiline, rasagiline): While selective MAO-B inhibitors are often used with levodopa/carbidopa, high doses or non-selective use can still pose a risk.
• Phenytoin: May reduce the therapeutic effect of levodopa.
• Papaverine: May reduce the therapeutic effect of levodopa.
• Tricyclic antidepressants: Rare cases of hypertension and dyskinesia have been reported.

• Nausea
• Vomiting
• Orthostatic hypotension
• Dyskinesia
• Hallucinations
• Confusion
• Dizziness
• Sleepiness
• Unusual urges (e.g., gambling, hypersexuality)

Carbidopa is Pregnancy Category C. Animal studies have shown adverse effects on the fetus. There are no adequate and well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk to the fetus.

It is not known whether carbidopa is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Safety and effectiveness in pediatric patients have not been established. Not recommended for use in children.

No specific dose adjustments are typically required based solely on age. However, elderly patients may be more sensitive to the central nervous system and cardiovascular side effects of levodopa/carbidopa (e.g., orthostatic hypotension, hallucinations, dyskinesia), requiring careful titration and monitoring.

• Carbidopa is almost always used in combination with levodopa to treat Parkinson's disease. Its primary role is to reduce the peripheral side effects of levodopa, allowing more levodopa to reach the brain.
• A minimum of 70-100 mg of carbidopa per day is generally required to fully inhibit peripheral DOPA decarboxylase and minimize levodopa's peripheral side effects.
• Standalone carbidopa 25mg tablets are useful for fine-tuning the carbidopa dose in patients who experience significant peripheral side effects (e.g., nausea, vomiting) with standard levodopa/carbidopa combination products, or when using lower carbidopa-containing formulations.
• Patients should be advised not to abruptly discontinue carbidopa/levodopa due to the risk of a neuroleptic malignant syndrome-like reaction.
• Monitor for orthostatic hypotension, dyskinesia, and psychiatric side effects, especially during dose adjustments.

• Dopamine agonists (e.g., pramipexole, ropinirole, rotigotine, apomorphine)
• MAO-B inhibitors (e.g., selegiline, rasagiline, safinamide)
• COMT inhibitors (e.g., entacapone, tolcapone, opicapone) - always used with levodopa/carbidopa
• Amantadine
• Anticholinergics (e.g., benztropine, trihexyphenidyl) - for tremor
• Adenosine A2A receptor antagonists (e.g., istradefylline)

If your symptoms or health issues persist or worsen, it is 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 it's a good idea to check with your pharmacist for more information. If you have any questions or concerns about this 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, including the amount taken and the time it happened, to facilitate prompt and effective treatment.