Levodopa + Carbidopa (FC tablet)

Levodopa + Carbidopa (FC tablet) Uses, Dosage, Side Effects, Food Interaction and all others data.

Levodopa is a prodrug of dopamine that is administered to patients with Parkinson's due to its ability to cross the blood-brain barrier. Levodopa can be metabolised to dopamine on either side of the blood-brain barrier and so it is generally administered with a dopa decarboxylase inhibitor like carbidopa to prevent metabolism until after it has crossed the blood-brain barrier. Once past the blood-brain barrier, levodopa is metabolized to dopamine and supplements the low endogenous levels of dopamine to treat symptoms of Parkinson's. The first developed drug product that was approved by the FDA was a levodopa and carbidopa combined product called Sinemet that was approved on May 2, 1975.

Levodopa is able to cross the blood-brain barrier while dopamine is not. The addition of a peripheral dopa decarboxylase inhibitor prevents the conversion of levodopa to dopamine in the periphery so that more levodopa can reach the blood-brain barrier. Once past the blood-brain barrier, levodopa is converted to dopamine by aromatic-L-amino-acid decarboxylase.

Levodopa + Carbidopa (FC tablet)
Uses
Dosage
Side Effect
Precautions
Interactions
Uses during Pregnancy
Uses during Breastfeeding
Accute Overdose
Food Interaction
Half Life
Volume of Distribution
Clearance
Interaction With other Medicine
Contradiction
Storage

Trade Name	Levodopa + Carbidopa (FC tablet)
Generic	Levodopa + Carbidopa (FC tablet)
Type
Therapeutic Class	Antiparkinson drugs
Manufacturer
Available Country	Bangladesh
Last Updated:	September 24, 2024 at 5:38 am

Uses

This tablet is indicated for the treatment of Parkinson's disease and syndrome. It is useful in relieving many of the symptoms of parkinsonism, particularly rigidity and bradykinesia. This tablet is frequently helpful in the management of tremor, dysphagia, sialorrhea and postural instability associated with Parkinson's disease and syndrome. Levodopa plus carbidopa before physiotherapy increases motor recovery after stroke.

Levodopa + Carbidopa (FC tablet) is also used to associated treatment for these conditions: Paralysis agitans, Parkinson's Disease (PD), Parkinsonism, Postencephalitic parkinsonism, Restless Legs Syndrome (RLS), Advanced Motor fluctuations

How Levodopa + Carbidopa (FC tablet) works

Levodopa by various routes crosses the blood brain barrier, is decarboxylated to form dopamine. This supplemental dopamine performs the role that endogenous dopamine cannot due to a decrease of natural concentrations and stimulates dopaminergic receptors.

Dosage

Levodopa + Carbidopa (FC tablet) dosage

If 100/10 mg tablet is used: Dosage may be initiated with one tablet three or four times a day. Titration upward may be required in some patients to achieve optimum dosage of carbidopa. The dosage may be increased by one tablet every day or every other day until a total of eight tablets (two tablets q.d.s.) is reached.For patients starting with 250/25 mg tablet: The initial dose is one half taken once or twice daily. However, this may not provide the optimal amount of Carbidopa needed by many patients. If necessary, add one-half every day or every other day until optimal response is reached. The suggested starting dosage for most patients taking more than 1500 mg of Levodopa a day is one tablet of 250/25 mg three or four times a day.Maintenance dose: Therapy should be individualized and adjusted according to the desired therapeutic response. When more levodopa is requried, 250/25 mg tablet should be substituted at a dosage of one tablet three or four times a day. If necessary, the dosage of 250/25 mg tablet may be increased by half to one tablet every other day to a maximum of eight tablets a day. Experience with a total daily dosage greater than 200 mg Carbidopa is limited.

Side Effects

Adverse effects that occur frequently in patients receiving Carbidopa-Levodopa are those due to the central neuropharmacologic activity of dopamine. These reactions usually can be diminished by dosage reduction. The most common adverse effects are dyskinesias including choreiform, dystonic, and other involuntary movements and nausea. Body as a whole: syncope, chest pain, anorexia. Cardiovascular: palpitation, orthostatic effects including hypotensive episodes, hypertension, phlebitis. Gastrointestinal: vomiting, gastrointestinal bleeding, development of duodenal ulcer, diarrhoea, dark saliva. Haemotologic: leukopenia, haemolytic and non-haemolytic anaemia, thrombocytopenia, agranulocytosis. Hypersensitivity: angioedema, urticaria, pruritus, Henoch-Schonlein purpura. Nervous System: dizziness, somnolence, paresthesia, delusions, hallucinations and paranoid ideation, depression with or without development of suicidal tendencies, dementia, dream abnormalities, agitation, confusion, increased libido. Respiratory: dyspnea. Skin: alopecia, rash, dark sweat. Urogenital: dark urine.

Toxicity

There is no readily available data for the use of levodopa in pregnancy. Rabbits treated with levodopa and carbidopa produced smaller litters and their offspring developed visceral and skeletal deformities. Levodopa may lower prolactin and interfere with lactation but there is limited human data to demonstrate this effect. Levodopa is present in human breast milk and so the potential effects of nursing while taking levodopa should be considered before prescribing levodopa to nursing mothers. There is currently a lack of data on the safety and effectiveness of using levodopa in pediatric patients. Patients over 65 years of age are more likely to experience adverse effects associated with taking levodopa, however this generally is not sufficient to exclude this patient group from treatment.

Precaution

Carbidopa-Levodopa is not recommended for the treatment of medicine-induced extrapyramidal reactions. Carbidopa Levodopa may be given to patients already taking Levodopa alone; however, the Levodopa must be discontinued at least 12 hours before Carbidopa-Levodopa started. Dyskinesias may occur in patients previously treated with Levodopa alone because Carbidopa permits more Levodopa to reach the brain and, thus, more dopamine to be formed. The occurrence of dyskinesias may require dosage reduction. All patients should be observed carefully for the development of depression with concomitant suicidal tendencies. Patients with past or current psychoses should be treated with caution. Carbidopa-Levodopa should be administered cautiously to patients with severe cardiovascular or pulmonary disease, bronchial asthma, renal, hepatic or endocrine disease, or a history of peptic ulcer disease or of convulsions.Care should be exercised to patients with a history of myocardial infarction who have atriai, nodal, or ventricular arrhythmia. In such patients, cardiac function should be monitored with particular care during the period of initial dosage administration and titration. Patients with chronic wide-angle glaucoma may be treated cautiously with Carbidopa-Levodopa, provided the intraocular pressure is weli controlled and the patient monitored carefully for changes in intraocular pressure during therapy.

Interaction

Symptomatic postural hypotension has occurred when Carbidopa-Levodopa is added to the treatment of a patient receiving antihypertensive medicines. Therefore, when therapy with CarbidopaLevodopa is started, dosage adjustment of the antihypertensive medicine may be required. There have been rare reports of adverse reactions, including hypertension and dyskinesia, resulting from the concomitant use of tricyclic antidepressants and Carbidopa-Levodopa. Studies demonstrate a decrease in the bioavailability of Carbidopa and/or Levodopa when it is ingested with ferrous sulphate or ferrous gluconate. Dopamine-2 receptor antagonists (e.g., phenothiazines, butyrophenones and risperidone) and isoniazid may reduce the therapeutic effects of Levodopa. In addition, the beneficial effects of Levodopa in Parkinson's disease have been reported to be reversed by phenytoin and papaverine. Patients taking these medicines with Carbidopa-Levodopa should be carefully observed for loss of therapeutic response. Concomitant therapy with selegiline and Carbidopa-Levodopa may be associated with severe orthostatic hypotension not attributable to Carbidopa-Levodopa alone.

Volume of Distribution

168L for orally inhaled levodopa.

Elimination Route

Orally inhaled levodopa reaches a peak concentration in 0.5 hours with a bioavailability than is 70% that of the immediate release levodopa tablets with a peripheral dopa decarboxylase inhibitor like carbidopa or benserazide.

Half Life

2.3 hours for orally inhaled levodopa. Oral levodopa has a half life of 50 minutes but when combined with a peripheral dopa decarboxylase inhibitor, the half life is increased to 1.5 hours.

Clearance

Intravenously administered levodopa is cleared at a rate of 14.2mL/min/kg in elderly patients and 23.4mL/min/kg in younger patients. When given carbidopa, the clearance of levodopa was 5.8mL/min/kg in elderyly patients and 9.3mL/min/kg in younger patients.

Elimination Route

After 48 hours, 0.17% of an orally administered dose is recovered in stool, 0.28% is exhaled, and 78.4% is recovered in urine

Pregnancy & Breastfeeding use

Although the effects of CarbidopaLevodopa on human pregnancy are unknown both Levodopa and combinations of Carbidopa and Levodopa have caused visceral and skeletal malformations in rabbits. Therefore, use of CarbidopaLevodopa in women of childbearing potential requires that the anticipated benefits of the medicine be weighed against possible hazards should pregnancy occur. It is not known whether Carbidopa is excreted in human milk. Because many medicines are excreted in human milk and because of the potential for serious adverse reactions in infants, a decision should be made whether to discontinue nursing or to discontinue the use of Carbidopa-Levodopa, taking into account the importance of the medicine to the mother.

Contraindication

Carbidopa-Levodopa tablet is contraindicated in patients with hypersensitivity to Carbidopa and Levodopa, and in patients with narrow-angle glaucoma. Since Levodopa may activate a malignant melanoma, Carbidopa-Levodopa should not be used in patients with suspicious undiagnosed skin lesions or a history of melanoma.

Special Warning

Use in children: Safety and effectiveness of Carbidopa-Levodopa in infants and children have not been established, and its use in patients below the age of 18 years is not recommended.