D-Dopa 100 mg+10 mg

Description

Indications
D-Dopa tablets are prescribed for the treatment of Parkinson’s disease and related syndromes. They effectively alleviate several symptoms of parkinsonism, including muscle rigidity and slow movement (bradykinesia). Additionally, these tablets assist in managing tremors, difficulty swallowing (dysphagia), excessive saliva production (sialorrhea), and postural instability associated with Parkinson’s disease. Levodopa combined with carbidopa has also been shown to enhance motor recovery when used before physiotherapy following a stroke.

Take this medication only as directed by a registered physician.

Pharmacology
Levodopa, a precursor of dopamine, crosses the blood-brain barrier and is converted into dopamine within the brain. This conversion helps alleviate Parkinson’s symptoms by replenishing dopamine levels. Carbidopa, a dopa decarboxylase (DDC) inhibitor, prevents the premature breakdown of levodopa outside the brain, ensuring a greater amount reaches the central nervous system for effective treatment.

• Levodopa: This compound serves as a dopamine precursor and, upon crossing the blood-brain barrier, is converted into dopamine. This is the primary mechanism through which it helps relieve Parkinson’s disease symptoms.
• Carbidopa: When taken orally, levodopa is rapidly broken down into dopamine before reaching the brain, reducing its effectiveness. Carbidopa inhibits this breakdown, allowing more levodopa to enter the brain, thus enhancing its therapeutic effect.

Dosage & Administration

• For 100/10 mg tablets: The initial dose is typically one tablet taken three to four times daily. Dosage adjustments may be necessary to achieve the optimal therapeutic effect. The dosage may be increased gradually by one tablet daily or every other day, up to a maximum of eight tablets per day (two tablets four times daily).
• For 250/25 mg tablets: The starting dose is usually half a tablet taken once or twice a day. If needed, the dosage may be increased gradually, adding half a tablet every day or every other day until the desired response is achieved. For patients requiring more than 1500 mg of levodopa daily, the recommended starting dose is one tablet (250/25 mg) taken three to four times a day.
• Maintenance Dose: Treatment should be individualized based on patient response. If higher doses of levodopa are required, the 250/25 mg tablet should be taken three to four times daily. If necessary, the dose can be increased by half to one tablet every other day, up to a maximum of eight tablets daily. Dosages exceeding 200 mg of carbidopa per day have limited clinical experience.

Take this medication only as directed by a registered physician.

Drug Interactions

• Adding Carbidopa-Levodopa to an existing antihypertensive regimen may lead to postural hypotension, requiring dose adjustments of the antihypertensive medication.
• Rare cases of hypertension and involuntary movements (dyskinesia) have been reported when taken with tricyclic antidepressants.
• Iron supplements (ferrous sulfate or ferrous gluconate) may reduce the absorption of carbidopa and levodopa.
• Dopamine-2 receptor antagonists (e.g., phenothiazines, butyrophenones, risperidone) and isoniazid may decrease the therapeutic effects of levodopa.
• Medications such as phenytoin and papaverine have been reported to counteract levodopa’s benefits in Parkinson’s treatment.
• Combining selegiline with Carbidopa-Levodopa may result in severe orthostatic hypotension.

Contraindications
Carbidopa-Levodopa tablets should not be used in patients with:

• Hypersensitivity to levodopa or carbidopa.
• Narrow-angle glaucoma.
• Suspicious undiagnosed skin lesions or a history of melanoma, as levodopa may activate malignant melanoma.

Side Effects
Common side effects due to dopamine’s neuropharmacological activity may include:

• Neurological: Uncontrolled movements (dyskinesias such as choreiform and dystonic movements), dizziness, drowsiness, hallucinations, delusions, depression, confusion, and increased libido.
• Cardiovascular: Palpitations, fluctuations in blood pressure (hypotension or hypertension), and inflammation of blood vessels (phlebitis).
• Gastrointestinal: Nausea, vomiting, ulcers, bleeding, diarrhea, and dark-colored saliva.
• Hematologic: Blood disorders such as anemia, leukopenia, thrombocytopenia, and agranulocytosis.
• Respiratory: Shortness of breath (dyspnea).
• Skin & Hair: Rash, alopecia, excessive sweating with dark coloration.
• Urinary: Dark-colored urine.

Pregnancy & Lactation

• The effects of Carbidopa-Levodopa in pregnancy are not well studied, but animal studies have shown skeletal and visceral malformations. Therefore, it should only be used in pregnant women if the benefits outweigh potential risks.
• It is unknown whether carbidopa is excreted in human breast milk. Due to potential risks to infants, a decision should be made whether to discontinue the medication or stop breastfeeding.

Precautions & Warnings

• Not recommended for drug-induced extrapyramidal symptoms.
• Patients previously on levodopa alone should discontinue it at least 12 hours before starting Carbidopa-Levodopa.
• Dyskinesias may occur due to increased dopamine levels and may require dose adjustment.
• Patients should be monitored for depression and suicidal tendencies. Caution is advised for those with a history of psychosis.
• Use with caution in patients with severe cardiovascular disease, pulmonary conditions, asthma, kidney, liver, or endocrine disorders, a history of ulcers, or a history of seizures.
• Patients with a history of heart attack and irregular heartbeat should be closely monitored, especially during initial dosing and adjustments.
• Individuals with chronic wide-angle glaucoma can be treated with Carbidopa-Levodopa if intraocular pressure is well controlled and regularly monitored.

Use in Special Populations

• Children: The safety and efficacy of Carbidopa-Levodopa in patients under 18 years have not been established, so its use in this population is not recommended.

Therapeutic Class
Antiparkinsonian drugs

Storage Conditions
Store in a cool, dry place away from light.