Carbidopa and levodopa teva

Carbidopa and levodopa-Teva is a combination antiparkinsonian drug that contains a dopamine metabolic precursor (levodopa) and a substance that inhibits peripheral dopa decarboxylase (carbidopa).

The symptoms of shaking palsy are thought to be caused by a deficiency of dopamine. When dopamine levels are normal, it is a neurotransmitter and is produced by certain brain cells that control muscle activity. Therefore, it is thought that movement disorders occur due to a deficiency of dopamine in the body.

Indications Carbidopa and levodopa teva

It is used during shaking palsy.

Release form

The medicinal substance is released in tablets - 10 pieces inside a blister pack. There are 5 or 10 such packs in a pack.

Pharmacodynamics

The antiparkinsonian activity of levodopa is associated with its transformation into dopamine (due to decarboxylation occurring directly within the central nervous system), as a result of which the lack of dopamine within nerve cells is replenished.

Carbidopa cannot cross the blood-brain barrier; it prevents the processes of extracerebral decarboxylation of levodopa, which increases its entry into the brain with subsequent transformation into dopamine within the central nervous system. These processes cause a weakening of the signs of shaking palsy in a large number of patients.

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Pharmacokinetics

Both active components of the drug are well absorbed; plasma Cmax values are noted after 1-3 hours. The half-life of levodopa (with the effect of carbidopa) is approximately 2 hours. Under the influence of carbidopa, plasma excretion of levodopa decreases by 50%. Under the influence of carbidopa, levodopa is usually transformed into amino acids (a small part is transformed into catecholamine derivatives). All metabolic components of levodopa with carbidopa are excreted in the urine.

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Dosing and administration

The selection of the optimal daily dosage of the medication is achieved through careful titration for each individual patient.

Taking into account the intensity of the pathology, it may take approximately six months to achieve optimal drug effect.

Individuals not using levodopa.

People who start using the drug should first take half a tablet 1-2 times a day. If necessary, add another half tablet daily or with daily breaks until the required amount of carbidopa is obtained.

The medicinal effect develops immediately on the day of taking (sometimes even after the first dose). Full effectiveness is achieved after 7 days (if using only levodopa, this takes weeks or months).

People who have used levodopa.

Levodopa administration should be stopped at least 12 hours (or 24 hours if slow-release drugs were used) before starting treatment with the medication. Levodopa can be taken in the morning and then not used at night. The dose should be approximately 20% of the previous daily dosage of levodopa.

Initial portion.

Individuals who consume less than 1.5 g of levodopa per day should initially take 0.075-0.1 g of carbidopa, as well as 0.3-0.4 g of levodopa (use the medication with a dosage in the proportion of 1:4 carbidopa/levodopa), in 3-4 doses.

People who consume more than 1.5 g of levodopa per day are initially prescribed to take 1 tablet of the medication 3-4 times per day.

Maintenance portion.

The medicine must be used taking into account the individual characteristics of the person, changing the dose gradually (taking into account the medicinal effect).

If it is necessary to take a larger volume of levodopa, the dosage can be increased to 1 tablet 3-4 times a day. If necessary, the dose can be increased by 0.5-1 tablet per day (in this case, no more than 8 tablets can be taken per day).

In cases where other decarboxylase inhibitors are used during the transfer of a patient from levodopa to Carbidopa and Levodopa-Teva, the administration of the drugs must be stopped at least 12 hours before using the medication. The drug intake must be started with a dose similar to the volume of levodopa and the decarboxylase inhibitor in the previous medications.

Persons using other antiparkinsonian drugs.

The combination of drugs and MAO-B inhibitors can enhance the medicinal activity of the former in controlled manifestations of dyskinesia or akinesia.

Other standard antiparkinsonian agents other than levodopa may be continued while carbidopa is being administered with levodopa, although the doses administered may require adjustment.

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Use Carbidopa and levodopa teva during pregnancy

There is no information on the effect of Carbidopa and Levodopa-Teva on pregnancy, but Levodopa and its combination with Carbidopa have resulted in abnormalities in the development of the skeleton with internal organs during animal tests. The drug should not be used during breastfeeding and pregnancy. Women of reproductive age who use the drug should use reliable contraception.

There is no information on whether the drug is excreted in breast milk. To prevent adverse effects in infants, a decision should be made to discontinue the drug or stop breastfeeding (taking into account the need for the woman to take it).

Contraindications

Among the contraindications:

• severe sensitivity associated with the active ingredients of the drug or other of its components;
• glaucoma;
• severe heart failure;
• cardiac arrhythmia of a severe nature;
• severe psychosis;
• combined use with selective MAO-A IMs, as well as non-selective MAO IMs (except for small doses of some MAO-B IMs). These medications should be discontinued at least 14 days before starting to use the drug;
• suspicious or undiagnosed epidermal diseases or a history of melanoma.

The medication is not prescribed to individuals who should not take sympathomimetics.

Side effects Carbidopa and levodopa teva

Negative symptoms that occur when taking drugs are usually related to the neuropharmacological activity of dopamine. They usually disappear or weaken after reducing the dose.

Often, when using the medication, dyskinesia (dystonic, choreiform and other movements of an involuntary nature) appears. If blepharospasms and muscle spasms occur, the dosage should be reduced.

Other serious side effects include mental changes (psychosis with paranoid thoughts, as well as depression with or without suicidal tendencies) and dementia. There are reports of hypersexuality or pathological gambling, as well as increased libido (especially when using large doses of the drug). Such symptoms disappear after reducing the dosage or stopping the medication.

Among the negative manifestations associated with levodopa and its combinations:

• lesions of the lymph and hematopoietic processes: anemia (also hemolytic), thrombocyto- or leukopenia and agranulocytosis;
• immune disorders: manifestations of intolerance, including urticaria and Quincke's edema;
• disorders of the cardiovascular system: fainting, palpitations, phlebitis, heart rhythm disorders, increased blood pressure, tendency to loss of consciousness and orthostatic symptoms, including decreased blood pressure;
• problems with the functioning of the nervous system: ataxia, chorea, bradykinesia or dyskinesia, dizziness and the so-called "on-off" phenomenon (sometimes occurs several months or years after the start of therapy with the introduction of levodopa; most likely, it develops due to the progression of the disease (in such cases, it may be necessary to change the size of the portions and the intervals between their administrations)). In addition, trismus, dystonia, increased tremor affecting the hands, muscle spasms, motor and extrapyramidal manifestations, paresthesia, muscle twitching, NMS, loss of consciousness and a tendency to fainting, as well as gait disorder, convulsions and activation of latent oculosympathetic syndrome;
• mental disorders: mania, depression, confusion, exhaustion, nightmares and suicide attempts. Also insomnia, dizziness, dementia, delirium, euphoria, severe anxiety and hallucinations. Also on the list are changes in mental status (this includes temporary psychosis and paranoid thinking), agitation, fear, seizures, disturbances in thinking or gait, headaches, disorientation and numbness, as well as sudden intense drowsiness;
• gastrointestinal tract lesions: dysphagia, diarrhea, dry mouth, dyspepsia, hypersalivation, bruxism and nausea, as well as the appearance of a bitter taste, hiccups, vomiting and bloating, constipation, abdominal pain, glossalgia, pain of a gastrointestinal nature, bleeding inside the gastrointestinal tract, burning tongue, dark saliva and ulcers affecting the duodenum;
• problems with metabolic processes: swelling, weight gain or loss, and anorexia;
• disorders associated with the subcutaneous layers and epidermis: hyperhidrosis, alopecia, itching, activation of malignant melanoma, hyperemia, rashes, dark sweat and rheumatic purpura;
• problems with the respiratory system: hoarse voice, dyspnea, pain in the chest area and difficulty breathing;
• lesions of the musculoskeletal structure: muscle spasms;
• urinary dysfunction: urinary incontinence or retention, priapism and dark urine;
• visual disturbances: diplopia, blurred vision, gaze spasm, mydriasis, blepharospasm, oculomotor crisis. Blepharospasm may be an early sign of poisoning;
• changes in test results: increased liver function values (ALT, together with alkaline phosphatase and AST, bilirubin, creatinine, LDH, uric acid and blood urea nitrogen), a positive response to the Coombs test, increased serum sugar levels, decreased hematocrit with hemoglobin, bacteriuria and leukocytosis with hematuria;
• other: fatigue, general feeling of weakness, sharp exacerbation of existing diseases, deterioration of health, hyperemia, flushing of the skin of the face and melanoma of a malignant nature;
• disorders of impulsive decisions: overeating and impulsive need to make purchases when administering dopamine agonists or other drugs containing dopamine (including levodopa and carbidopa).

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Overdose

Early signs of intoxication include: involuntary movements, muscle twitching, heart rhythm disturbances, increased blood pressure, blepharospasm of a tonic form, loss of appetite and, along with this, increased heart rate, insomnia, anxiety-like agitation, confusion, and a feeling of restlessness.

Gastric lavage must be performed immediately along with induction of vomiting.

Symptomatic actions: infusions are used with caution; the degree of patency of the respiratory tract must be taken into account. In case of arrhythmia, therapy is carried out with ECG monitoring. There are no data on the use of dialysis in poisoning. The use of pyridoxine will be ineffective.

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Interactions with other drugs

Caution is required when using with the following medications.

Antihypertensive drugs.

In individuals using some antihypertensive drugs, the use of combinations of levodopa and a decarboxylase inhibitor has resulted in symptomatic orthostatic collapse. Because of this, the dosage of the antihypertensive agent should be adjusted at the initial stage of therapy.

Antidepressants.

There are isolated reports regarding the occurrence of adverse effects (including dyskinesia and increased blood pressure) associated with the combination of drugs and tricyclics.

The medication is permitted to be used only together with selective MAO-B inhibitors, in recommended doses (for example, with selegiline).

Anesthetics.

When administered together with anesthetics, arrhythmia may occur.

Anticholinergic drugs.

They may show synergy with levodopa in reducing tremor, so this feature is often used to increase the drug effect. But it should be taken into account that such a combination can lead to an exacerbation of uncontrolled movements.

Large doses of these substances can weaken the positive effects of levodopa, because they reduce the rate of its absorption, thereby increasing the intragastric metabolic processes of the drug.

Other medications.

Benzodiazepines, phenytoin with phenothiazines, butyrophenones, papaverine and isoniazid can weaken the medicinal activity of levodopa.

Metabolic processes of levodopa are enhanced by the administration of anticonvulsants.

Because levodopa competes with certain amino acids, people on a high-protein diet may experience decreased absorption of the drug.

The use of carbidopa prevents the intensification of metabolic processes with the conversion of levodopa to dopamine, which occur under the influence of pyridoxine. The drug is approved for use in people with Parkinsonism who use substances containing pyridoxine hydrochloride.

Administration in combination with selegiline may cause severe orthostatic collapse.

Fe-containing drugs can inhibit the absorption of levodopa.

Sympathomimetics potentiate the negative symptoms of levodopa associated with cardiovascular disease.

Amantadine and dopamine antagonists can be combined with the drug. When used together, dosage adjustments may be necessary.

Plasma levodopa values are increased by the use of metoclopramide.

Administration together with elements that inhibit catechol methyltransferase (entacapone with tolcapone) may increase the level of bioavailability of levodopa.

Combination with other antiparkinsonian substances that do not contain levodopa is allowed.

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Storage conditions

Carbidopa and levodopa-teva should be stored in a place closed to small children. Temperature values are a maximum of 25°C.

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Shelf life

Carbidopa and levodopa-Teva can be used within 36 months from the date of sale of the drug.

Application for children

There is no information regarding the safety of the drug in pediatrics, which is why it is not used in individuals under 18 years of age.

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Analogues

Analogues of the drug are the medications Levokom, Duodopa, Stalevo with Levocarbhexal and Nakom.

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