CarbidopaandLevodopaCRTablets

Common name: Carzobidopa sustained-release tablets
Trade name: Xining
Full names: CarbidopaandLevodopaCRTablets

Indications:
1. Primary Parkinson's disease.
2. Post-encephalitis Parkinson's syndrome.
3. Symptomatic Parkinson's syndrome (carbon monoxide or manganese poisoning).
4. Patients with Parkinson's disease or Parkinson's syndrome taking vitamin preparations containing pyridoxine and vitamin B6.
5. For patients who have previously used levodopa/decarboxylase inhibitor compound preparations or treated with levodopa alone and have symptoms of end-of-dose deterioration ("fading" phenomenon), peak-dose dyskinesia, akinesia, or similar short-term dyskinesia, the "off" time can be reduced.

Usage and dosage:
The ratio of carbidopa to levodopa in this product is 1:4. Each tablet of this product contains 50mg carbidopa and 200mg levodopa.
The daily dose of this product must be carefully adjusted and determined. Patients should be closely monitored during dose adjustment, with particular attention to the emergence or worsening of nausea or abnormal involuntary movements including dyskinesia, chorea, and dystonia.
This product can be taken as a whole tablet or half a tablet. This method of taking can maintain the sustained-release properties of the tablets, and the tablets cannot be chewed or crushed. While taking this product, other standard anti-Parkinson's disease medications may be continued in addition to levodopa, but dosage adjustments are required. Because carbidopa prevents the reversal of the effects of levodopa caused by pyridoxine, it may be used in patients receiving supplementary therapy with pyridoxine. At the same time, patients receiving pyridoxine (vitamin B6) supplementation can take this product.
Starting dose, patients who have not received levodopa treatment: The recommended starting dose of this product is half a tablet twice a day.
For patients who need more levodopa, this product can be taken 1-4 half tablets a day in two divided doses, and is generally well tolerated. This product can also be used as initial treatment when appropriate.
The recommended starting dose of this product is 1 tablet 2 to 3 times a day. The starting dose of levodopa should not be higher than 600mg per day or the interval between doses should not be shorter than 6 hours.

Adverse reactions:
The most common adverse reaction is dyskinesia (an abnormal involuntary movement).
Other common adverse reactions (more than 2%) are: nausea, hallucinations, confusion, dizziness, chorea and dry mouth.
Rarely occurring adverse reactions (1%-2%) include: abnormal dreams, dystonia, drowsiness, insomnia, depression, weakness, vomiting and anorexia.
Other adverse reactions reported in clinical studies and post-marketing include: Systemic: chest pain, syncope Cardiovascular: palpitations, orthostatic effects including episodes of hypotension Gastrointestinal: constipation, diarrhea, dyspepsia, gastrointestinal pain, dark saliva Hypersensitivity: angioedema, urticaria, pruritus Metabolic: weight loss Nervous/Psychiatric System: Neuroleptic malignant syndrome (see Precautions), agitation, anxiety, decreased brain reactivity, paresthesia, disorientation, fatigue, headache, extrapyramidal and movement disorders, falls, gait abnormalities, muscle spasms, on-off phenomenon, increased libido, psychotic episodes including delusions and paranoid ideation effects.

Taboo:
Non-selective monoamine oxidase (MAO) inhibitor drugs cannot be taken at the same time as this product. These inhibitors must be stopped at least two weeks before starting treatment with this product. This product can be used in combination with a selective type B monoamine oxidase inhibitor (such as selegiline hydrochloride) at the dosage recommended by the manufacturer. This product is contraindicated in persons with known hypersensitivity to any component of this drug and patients with angle-closure glaucoma. Because levodopa may activate malignant melanoma, it is contraindicated in patients with suspected skin lesions or a history of melanoma.

Notes:
Patients who are receiving levodopa monotherapy must wait at least 8 hours after stopping levodopa before starting treatment with this product (if taking extended-release levodopa, the drug should be stopped for at least 12 hours).
Patients previously treated with levodopa alone may develop dyskinesias because carbidopa allows more levodopa to enter the brain, thereby producing more dopamine. If movement disorders occur, the dose should be reduced.
Like levodopa, this product may cause involuntary movements and mental disorders. It is currently believed that this is due to increased dopamine levels in the brain after taking levodopa. At this time, the dose needs to be reduced.
All patients should be carefully observed to prevent depression with suicidal tendencies. Patients with a past or current history of mental illness should be treated with greater caution.
Patients with severe cardiovascular disease, lung disease, bronchial asthma, kidney disease, liver disease, endocrine disease, and a history of digestive system ulcers or convulsions should use this product with caution.
Patients with atrial, nodal or ventricular arrhythmias and a recent history of myocardial infarction should use this product with caution. For these patients, cardiac function should be monitored, especially during initial administration and dose adjustment.
Patients with chronic wide-angle glaucoma should use this product with caution. During treatment, they should control intraocular pressure well and pay attention to changes in intraocular pressure.
When anti-Parkinson's disease drugs are suddenly discontinued, antipsychotic malignant syndrome symptoms such as muscle rigidity, increased body temperature, mental changes and increased serum creatine phosphokinase levels may occur. Therefore, patients should be closely monitored when the combined carbidopa/levodopa preparation is suddenly reduced or discontinued, especially in patients receiving antipsychotic medications.
This product is not suitable for the treatment of drug-induced extrapyramidal symptoms. During long-term treatment, regular examinations of liver, hematopoietic system, cardiovascular system and renal function should be carried out. Melanoma: Epidemiological studies show that patients with Parkinson's disease have a higher risk of melanoma than the general population (approximately 2-6 times). It's unclear whether the higher risk of melanoma in Parkinson's patients is related to the disease itself or other factors such as treatments.
For the above reasons, patients and prescribers are advised to regularly monitor for the occurrence of melanoma when using Xining for any indication. In fact, regular skin examinations should be performed by a professionally qualified doctor (e.g., a dermatologist). Pathological gambling, hypersexuality, and increased libido have been reported in Parkinson's disease patients treated with dopamine agonists.

Store:
Save below 30℃, avoid light and moisture.

Mechanism of action:
Carbidopa controlled-release tablets are polymer-based compound controlled-release tablets of carbidopa (an aromatic amino acid decarboxylase inhibitor) and levodopa (the metabolic precursor of dopamine). It is used to treat Parkinson's disease and Parkinson's syndrome. This product is particularly helpful for patients who have previously used traditional levodopa/desulfonate inhibitor combination preparations and have predictable peak dose dyskinesia and unpredictable ataxia to shorten the "off" time. Patients with Parkinson's disease treated with preparations containing levodopa may develop ataxia characterized by dose loss, peak-dose dyskinesia, and akinesia. Further manifestations of ataxia are characterized by unpredictable swings from movement to rest (switching phenomenon). Although the cause of ataxia is not completely understood, treatment that produces stable levodopa plasma concentrations has been shown to reduce symptoms. Levodopa relieves symptoms of Parkinson's disease through decarboxylation in the brain to form dopamine. Carbidopa cannot pass the blood-brain barrier and only inhibits peripheral decarboxylation of levodopa, allowing more levodopa to enter the brain and be converted into dopamine. This avoids the frequent use of large doses of levodopa. Low doses of levodopa can reduce or may help eliminate adverse effects in the gastrointestinal tract and cardiovascular system, particularly those related to the formation of dopamine in peripheral tissues.