Parkinson's Symptoms/Sinemet

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SINEMET® is widely prescribed for the treatment of Parkinson's disease and some Parkinson's_Plus syndromes.

Active ingredients

Carbidopa, is an inhibitor of aromatic amino acid decarboxylation, and is a white, crystalline compound, slightly soluble in water, with a molecular weight of 244.3. It is designated chemically as (—)-L-α-hydrazino-α-methyl-β-(3,4-dihydroxybenzene) propanoic acid monohydrate. Its empirical formula is C₁₀H₁₄N_2O4•H_2O.

Levodopa, an aromatic amino acid, is a white, crystalline compound, slightly soluble in water, with a molecular weight of 197.2. It is designated chemically as (—)-L-α-amino-β-(3,4-dihydroxybenzene) propanoic acid. Its empirical formula is C₉H₁₁NO₄.

Inactive ingredients

Hydroxypropyl cellulose

Pregelatinized starch

Crospovidone

Microcrystalline cellulose

Magnesium stearate

SINEMET 10-100 and 25-250 Tablets also contain:-

FD&C Blue #2/lndigo Carmine AL.

SINEMET 25-100 Tablets also contain:-

D&C Yellow #10 Lake.

Most common adverse reactions to SINEMET

Dyskinesia

Nausea

Less common adverse reactions to SINEMET

Body as a Whole

Chest pain, asthenia.

Cardiovascular

Cardiac irregularities, hypotension, orthostatic effects including orthostatic hypotension, hypertension, syncope, phlebitis, palpitation.

Gastrointestinal

Dark saliva, gastrointestinal bleeding, development of duodenal ulcer, anorexia, vomiting, diarrheoa, constipation, dyspepsia , dry mouth, taste alterations.

Hematologic

Agranulocytosis, hemolytic and non-hemolytic anemia, thrombocytopenia, leukopenia.

Hypersensitivity

Angioedema, urticaria, pruritus, Henoch-Schonlein purpura, bullous lesions (including pemphigus-like reactions).

Musculoskeletal

Back pain, shoulder pain, muscle cramps.

Nervous System/Psychiatric

Psychotic episodes including delusions, hallucinations, and paranoid ideation, neuroleptic malignant syndrome, bradykinetic episodes ("on-off" phenomenon), confusion, agitation, dizziness, somnolence, dream abnormalities including nightmares, insomnia, paresthesia, headache, depression with or without development of suicidal tendencies, dementia, pathological gambling, increased libido including hypersexuality, impulse control symptoms.

Respiratory

Dyspnea, upper respiratory infection.

Skin

Rash, increased sweating, alopecia, dark sweat.

Urogenital

Urinary tract infection, urinary frequency, dark urine.

Drug interactions

Symptomatic postural hypotension has occurred when SINEMET was added to the treatment of a patient receiving antihypertensive drugs.

Severe orthostatic hypertenson can occur for patients receiving MAO inhibitors (Type A or B).

There have been rare reports of adverse reactions, including hypertension and dyskinesia, resulting from the concomitant use of tricyclic antidepressants and SINEMET.

Dopamine D2 receptor antagonists (e.g. phenothiazines, butyrophenones, 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.

Iron salts may reduce the bioavailability of levodopa and carbidopa.

Although metoclopramide may increase the bioavailability of levodopa by increasing gastric emptying, metoclopramide may also adversely affect disease control by its dopamine receptor antagonistic properties.

Further Reading

(1997)

Block et al carried out a multi-centre trial over 5 years comparing the effects of Sinemet (immediate Release) and Sinemet CR (Controlled Release) and found favourably for the latter.

Search the scientific literature (Sinemet)
Literature search: Use the following links to query the PubMed, PubMed Central and Google Scholar databases using the Search terms:- Parkinson's_Disease Sinemet. This will list the latest papers on this topic. You are invited to update this page to reflect such recent results, pointing out their significance. Pubmed (abstracts) Pubmed_Central (Full_Text) Google_Scholar