Carbidopa/levodopa Ext-rel Tabs

  • Parkinsonism

Carbidopa/levodopa Ext-rel Tabs Generic Name & Formulations

General Description

Carbidopa, levodopa; 25mg/100mg, 50mg/200mg.

Pharmacological Class

Dopa-decarboxylase inhibitor + dopamine precursor.

See Also

How Supplied

CR—contact supplier; Tabs—100

Carbidopa/levodopa Ext-rel Tabs Indications



Carbidopa/levodopa Ext-rel Tabs Dosage and Administration


≥18yrs: Do not crush or chew. Patients not receiving levodopa: initially one Sinemet CR 50–200 tab twice daily, at intervals of at least 6 hrs. Others: see literature. Allow 3 days between dosage adjustments. If given at intervals <4 hrs and/or divided doses not equal: give smaller doses at end of day. May add immediate-release Sinemet 25–100 or 10–100 in advanced disease.


<18yrs: not recommended.

Carbidopa/levodopa Ext-rel Tabs Contraindications


During or within 14 days of nonselective MAOIs (eg, phenelzine). Narrow-angle glaucoma. Undiagnosed skin lesions. History of melanoma.

Carbidopa/levodopa Ext-rel Tabs Boxed Warnings

Not Applicable

Carbidopa/levodopa Ext-rel Tabs Warnings/Precautions


Severe cardiovascular or pulmonary disease. Asthma. Renal, hepatic, or endocrine disorders. History of peptic ulcer or MI with residual arrhythmias. Suicidal tendencies. Psychosis. Orthostatic hypotension. Chronic wide-angle glaucoma. Discontinue levodopa at least 12 hrs before starting Sinemet or Sinemet CR. Sinemet CR not bioequivalent to Sinemet; see literature when switching forms. Monitor renal and liver function, intraocular pressure, blood counts. May stain body fluids. Pregnancy (Cat.C). Nursing mothers.

Carbidopa/levodopa Ext-rel Tabs Pharmacokinetics

See Literature

Carbidopa/levodopa Ext-rel Tabs Interactions


See Contraindications. Orthostatic hypotension with selegiline, antihypertensives. Antagonized by phenothiazines, butyrophenones, risperidone, phenytoin, papaverine. Hypertension, dyskinesia with tricyclic antidepressants. May be antagonized by iron, high protein diets. May cause false (+) urinary ketone test or false (–) urinary glucose (glucose oxidase) test.

Carbidopa/levodopa Ext-rel Tabs Adverse Reactions

Adverse Reactions

Dyskinesia, GI upset, hallucinations, confusion, psychological disturbances, depression, dizziness, headache, dream abnormalities, dystonia, cardiac arrhythmias, hypotension, dyspnea, on-off phenomenon, back pain, blepharospasm (may indicate excess dosage), hypertension, anticholinergic effects, anorexia, insomnia, leukopenia, renal and liver function disorders, seizures, neuroleptic malignant syndrome.

Carbidopa/levodopa Ext-rel Tabs Clinical Trials

See Literature

Carbidopa/levodopa Ext-rel Tabs Note


Formerly known under the brand name Sinemet CR.

Carbidopa/levodopa Ext-rel Tabs Patient Counseling

See Literature