Madopar

Drug name

[Common name] Duo Ba Si Jing Pian

Specifications

Levodopa 200mg, benserazide 50mg

Indications

It is used for Parkinson's disease, symptomatic Parkinson's syndrome (post-encephalitis, arteriosclerosis or toxicity), but does not include drug-induced Parkinson's syndrome.

Usage and Dosage

The most appropriate daily dosage of Madopar® must be determined according to the conditions of different patients.

The following dosage table can be used as a basic reference

1. Initial treatment

The first recommended dosage is 1/2 tablet of Madopar® three times a day. From now on, the daily dosage will be increased by 1/2 tablet each week. until the appropriate therapeutic dose for the patient is reached. If the patient sees a doctor regularly, the dosage can be increased faster. For example, the daily dosage can be increased twice a week, with 1/2 tablet of Madopar® added each time. This way, the effective dose can be reached quickly. The effective dose is usually between 2 and 4 tablets per day, taken 3 to 4 times a day. It is rarely necessary to take more than 5 tablets of Madopar® per day. For example:

Madopar@tablet quantity

Morning Noon 4pm Evening Total tablets taken daily

First week 1/2 1/2 -- 1/2 1+1/2

Second week 1/2 1/2 1/2 1/2 2

Third week 1 1/2 1/2 1/2 2+1/2

First week 1 1 1/2 1/2 3

If satisfactory improvement has not been achieved, the dosage should be increased further, but at a slower rate.

Sixth and Seventh Weeks 1 1 1 1/2 2+1/2

Eighth and Nine Weeks 1 1 1 1 4

If it is necessary to give more than 4 Madopar® tablets per day, then the dose should be increased at monthly intervals.

For a small number of patients, the initial recommended dosage listed in the table is too large, and should be gradually increased from 1/4 tablet to 1/2 tablet to the same total daily dosage.

2. Maintenance therapy

The daily dosage of Madopar® should be divided into at least 3 times. The average maintenance dose is 3 times a day, one piece of Madopar® each time. However, because symptom improvement may fluctuate, daily dosage allocation (in terms of dosage and timing for each patient) is determined on an individual patient basis. If a patient begins to experience significant fluctuations in efficacy (such as an "on-off" phenomenon), this situation can often be significantly improved by taking 1/4 tablet of Madopar®.

In principle, the daily dosage does not change. You can use 1/4 tablet of Madopar® to partially or completely replace the original allocation of Madopar®, but the interval must be shortened:

When you take 1/2 tablet of Madopar® originally, you can replace it with 1/4 tablet each in two doses.

The originally taken 1 tablet of Madopar® can be replaced by taking 1/4 tablet each in 4 times.

3. Patients who used to take levodopa and now switch to Madopar®

If a patient who used to take levodopa needs to switch to 1 tablet of Madopar®, the change method is as follows. The number of Madopar® tablets taken daily is equivalent to half of the patient's current daily dose of levodopa 500 mg/tablet or half of the total number of capsules minus 1/2 tablets. For example, if a patient takes 2 grams of levodopa per day (four 500 mg levodopa tablets or capsules per day), the doctor's prescription for Madopar® should be 2-1/2 times a day. =1½ pieces. For all patients, the minimum initial dose is 1/2 tablet twice daily.

Patients should be closely observed for one week and, if necessary, the dosage of Madopar® should be increased until satisfactory response is achieved (the same dosage schedule as for patients who have not previously been treated with levodopa). If a worsening of the patient's clinical condition is observed, the dosage may be increased earlier.

4. General precautions

In a few cases, serious adverse reactions occur in the early stages of treatment. At this time, the dose should not be further increased or even reduced. However, interruption of treatment is rarely necessary. When the adverse reactions disappear or are tolerated, the daily dose can be increased again, but more slowly, for example, only 1/2 tablet of Madopar® every 2-3 weeks. When a patient takes more than the usual effective dose of Madopar® (such as more than 3 tablets of Madopar® per day), the interval between dose increases must be longer, because it takes a certain amount of time for the drug to achieve full therapeutic effects.

Like all alternatives, treatment with Madopar® is long-term. If symptoms improve after 4 weeks of treatment, Madopar® should be continued to achieve good results. Sometimes it is necessary to take Madopar® for more than 6 months to achieve the best results.

Adverse reactions

Blood and lymphatic system: Hemolytic anemia, transient leukopenia and thrombocytopenia have been reported in rare cases. Therefore, during long-term treatment with levodopa-containing drugs, blood cells and liver and kidney functions should be checked regularly.

Metabolism and Nutrition: Anorexia has been reported.

Psychiatric symptoms: Patients treated with Madopar may experience depression, but this may also be a clinical manifestation in patients with Parkinson's disease and restless legs syndrome. Agitation, anxiety, insomnia, hallucinations, delusions, and transient disorientation may occur in elderly patients or those with similar medical history.

Nervous system: Loss of taste or dysgeusia have been reported in individual cases. In the later stages of treatment, movement disorders (such as chorea-like movements or athetosis) may occur, and reducing the dosage can usually eliminate or tolerate the symptoms. With the prolongation of treatment time, fluctuations in treatment response may also occur, including: freezing episodes, end-of-dose deterioration, and "on-off" phenomena. It can usually be eliminated or tolerated by adjusting the dose or administering small amounts multiple times, and then the dose can be gradually increased to enhance the effect. Taking Madopar® has been associated with drowsiness and, rarely, excessive daytime hypnotic states or sudden sleep attacks.

Heart: Arrhythmia occasionally seen.

Vascular: Occasionally orthostatic hypotension. Reducing the dose of Madopar® usually improves orthostatic hypotension.

Gastrointestinal tract: Nausea, vomiting and diarrhea have been reported during use of Madopar®. Gastrointestinal adverse reactions mainly occur at the beginning of treatment and can be basically controlled by taking them with food or drinks or slowly increasing the dose.

Skin and subcutaneous tissue: Rare skin allergic reactions such as itching and rash.

Research report:

Transient increases in liver transaminases and alkaline phosphatase may occur. Increased gamma-glutamyl transferase has been reported.

It was found that blood urea nitrogen increased during administration of Madopar®.

The color of urine may change, usually light red, and become darker after standing.

There have been case reports abroad of patients using dopamine receptor agonists to treat Parkinson's disease and developing pathological gambling, increased sexual desire, and hypersexuality, especially at high doses, which can generally be reversed after reducing the treatment dose or discontinuing the drug.

Contraindications

Medopar® is contraindicated in patients with known hypersensitivity to levodopa, benserazide or their excipients.

Concomitant use of Madopar® with non-selective monoamine oxidase inhibitors, except selective monoamine oxidase B inhibitors (such as selegiline and rasagiline) and selective monoamine oxidase A Inhibitors (such as moclobemide) are not prohibited from combined use. Combined use of monoamine oxidase A and monoamine oxidase B The inhibitor is equivalent to a non-selective monoamine oxidase inhibitor and should not be used in combination with Madopar® (see Drug Interactions).

Madopar® is contraindicated in patients with endocrine, renal (except dialysis), hepatic decompensation, heart disease, mental illness, or angle-closure glaucoma.

Madopar® is contraindicated in patients under 25 years of age (must be skeletally fully developed).

Madopar® is contraindicated in pregnancy and in women of potential pregnancy who are not using effective contraceptive measures (such as pregnant or lactating women). If the patient becomes pregnant while taking this medication, the medication should be discontinued (as recommended by the prescribing physician).

Notes

Monoamine oxidase inhibitors should not be administered to patients during treatment with Madopar®. Madopar® may potentiate the effects of sympathomimetics taken concomitantly. Therefore, close monitoring of the cardiovascular system is also essential. The dose of sympathomimetic drugs should also be reduced. Other antiparkinsonian drugs should not be stopped suddenly at the beginning of treatment with Madopar®, as the effects of the latter may take at least several days to take effect. In some cases, the dosage of other drugs should be gradually reduced over time.

Patients with myocardial infarction, coronary artery insufficiency or arrhythmia should undergo regular cardiovascular system examinations (especially electrocardiogram examinations).

Concomitant use of various antihypertensive treatments during treatment is allowed, but blood pressure should be measured regularly. Among the antihypertensive drugs, reserpine and alpha-methyldopa interfere with dopamine metabolism and may therefore antagonize the effects of Madopa®. The same is true for derivatives of phenothiazole and butyrophenone.

In low-dose multivitamin preparations, vitamin B6 is allowed.

Patients with gastric or duodenal ulcers or osteomalacia should be closely observed when taking this drug.

Patients with open-angle glaucoma should measure intraocular pressure regularly because levodopa can theoretically increase intraocular pressure.

As with long-term treatment with any drug, blood routine and liver and kidney functions should be checked regularly.

If patients treated with Madopar® require general anesthesia, Madopar® treatment should be continued until before surgery as much as possible, unless halothane anesthesia is used. Because patients treated with Madopar® can cause blood pressure fluctuations and cardiac arrhythmias when receiving halothane anesthesia, Madopar® should be stopped as much as possible 12-48 hours before surgery. Madopar® can be resumed after surgery and the dose can be gradually increased to the pre-surgery level.

Allergic reactions may occur in sensitive patients.

Depression may occur in patients treated with Madopar®, but this may also be a manifestation of the disease.

Patients with diabetes should frequently check their blood sugar and adjust the dosage of anti-diabetic drugs based on blood sugar levels.

Madopar® should not be stopped suddenly. Sudden discontinuation of Madopar® may lead to life-threatening neurotoxic reactions (such as high fever, muscle rigidity, possible psychological changes, and an increase in serum creatinine phosphokinase, etc.). If these symptoms and signs exist at the same time, the patient should be closely monitored by a physician (hospitalized if necessary) and given timely and appropriate symptomatic treatment, including resumption of Madopar® after appropriate evaluation.

Taking Madopar® can cause drowsiness and sudden sleep attacks. Although there are few reports that patients may suddenly experience sleepiness during daily activities without any warning, patients treated with Madopar® should be informed that the drug may have such side effects and should be careful when driving or operating machinery. Patients who experience drowsiness or sudden sleep attacks should avoid driving and operating machinery, and a dose reduction or discontinuation of treatment should be considered. (See "Ability to drive vehicles and operate machinery").

Ability to drive vehicles and operate machinery: Patients receiving levodopa who experience drowsiness and/or sudden somnolence must be informed that they should avoid driving or engaging in activities that may put them or others at risk of injury or death due to reduced alertness (such as operating machinery) until such recurring events and somnolence symptoms have completely resolved.

Drug dependence and drug abuse: A small proportion of patients with Parkinson's disease develop cognitive and behavioral impairments, which may be caused by increasing their medication dosage against medical advice or taking doses that far exceed those needed to treat movement disorders.

Dopaminergic drugs: Pathological gambling, increased libido and hypersexuality have been reported in patients treated with Madopar® for Parkinson's disease. There is no evidence that the above events are causally related to the use of Madopar, which is not a dopamine agonist. Nonetheless, it is recommended that patients be informed that Madopar® is a dopaminergic drug.

Management of Overdose

Symptoms and Signs

The signs and symptoms of overdose with Madopar are the same as those at therapeutic doses, but are more severe. Drug overdose can cause: cardiovascular adverse reactions (such as arrhythmia), mental disorders (such as confusion and insomnia), gastrointestinal reactions (such as nausea and vomiting), and abnormal involuntary movements, see [Adverse Reactions]

Treatment

The patient's vital signs should be monitored and appropriate supportive measures taken based on their clinical status. Systemic treatment of cardiovascular symptoms (eg, arrhythmias) or central nervous system symptoms (eg, respiratory stimulants or neuroleptics) may be needed in specific patients.