Management of acute overdosage with SINEMET CR (carbidopa-levodopa sustained release) is the same as with levodopa. Pyridoxine is not effective in reversing the actions of SINEMET CR (carbidopa-levodopa sustained release) .

General supportive measures should be employed, along with immediate gastric lavage. Intravenous fluids should be administered judiciously and an adequate airway maintained. Electrocardiographic monitoring should be instituted and the patient carefully observed for the development of arrhythmias; if required, appropriate antiarrhythmic therapy should be given. The possibility that the patient may have taken other drugs as well as SINEMET CR (carbidopa-levodopa sustained release) should be taken into consideration. To date, no experience has been reported with dialysis; hence, its value in overdosage is not known.

Based on studies in which high doses of levodopa and/or carbidopa were administered, a significant proportion of rats and mice given single oral doses of levodopa of approximately 1500-2000 mg/kg are expected to die. A significant proportion of infant rats of both sexes are expected to die at a dose of 800 mg/kg. A significant proportion of rats are expected to die after treatment with similar doses of carbidopa. The addition of carbidopa in a 1:10 ratio with levodopa increases the dose at which a significant proportion of mice are expected to die to 3360 mg/kg.

Nonselective MAO inhibitors are contraindicated for use with SINEMET CR (carbidopa-levodopa sustained release) . These inhibitors must be discontinued at least two weeks prior to initiating therapy with SINEMET CR (carbidopa-levodopa sustained release) . SINEMET CR (carbidopa-levodopa sustained release) may be administered concomitantly with the manufacturer's recommended dose of an MAO inhibitor with selectivity for MAO type B (e.g., selegiline HCI) (see PRECAUTIONS: DRUG INTERACTIONS).

SINEMET CR (carbidopa-levodopa sustained release) is contraindicated in patients with known hypersensitivity to any component of this drug, and in patients with narrow-angle glaucoma.

Because levodopa may activate a malignant melanoma, SINEMET CR (carbidopa-levodopa sustained release) should not be used in patients with suspicious, undiagnosed skin lesions or a history of melanoma.

Last reviewed on RxList: 3/28/2011
This monograph has been modified to include the generic and brand name in many instances.