Sinemet CR Disease Interactions

Carbidopa-levodopa products are contraindicated in patients with narrow-angle glaucoma.

Cardiac irregularities occur infrequently in patients on dopamine agonists. The initial administration and titration is recommended to occur under close cardiac monitoring in a facility equipped for intensive cardiac care. Adverse cardiac affects may include palpitation, sinus tachycardia, ventricular tachycardia, extrasystole, atrial flutter or fibrillation, or block of AV conduction.

Dopamine agonists may impair the systemic regulation of blood pressure, with resultant orthostatic hypotension, especially during dose escalation. Therapy with dopamine agonists should be monitored carefully in patients with Parkinson's disease since they may have an impaired ability to respond to an orthostatic challenge, and also in patients receiving antihypertensive drugs.

The use of dopamine agonists is contraindicated in patients with neuroleptic malignant syndrome (NMS). NMS is characterized by hyperthermia, muscle rigidity, altered mental status, irregular pulse or blood pressure, tachycardia, and diaphoresis. The syndrome may rarely be precipitated by abrupt discontinuation of the dopamine agonist.

The use of dopamine agonists has been associated with psychiatric effects such as hallucinations, psychosis, confusion, anxiety, mania, hypomania, depression, rapid mood cycling, nightmares, and hypersexuality. Therapy with dopamine agonists should be administered cautiously in psychotic patients and all patients should be carefully observed for development of depression and suicidal tendencies.

Ordinarily, patients with major psychotic disorder should not be treated with dopaminergic antiparkinson agents, because of the risk of exacerbating psychosis. Hallucinations and psychotic-like behavior have been reported with dopaminergic medications. In addition, certain medications used to treat psychosis may exacerbate the symptoms of Parkinson's disease and may decrease the effectiveness of these drugs.

The use of levodopa is contraindicated in patients with acute closed-angle glaucoma. Levodopa (with or without carbidopa) may be used in patients with open-angle glaucoma who are receiving appropriate therapy.

The pharmacokinetics of levodopa have not been studied in patients with hepatic or renal impairment. Therapy with levodopa should be administered cautiously in patients with liver or disease. Periodic monitoring of hepatic and renal function is recommended during extended therapy.

The use of levodopa is considered by manufacturers to be contraindicated in patients with a history of melanoma or in patients with suspicious, undiagnosed skin lesions. Levodopa reportedly may activate malignant melanoma, although some investigators have found a causal relationship to be tenuous.

Because of the risk of bronchospasm, use of levodopa in patients with asthma, COPD, or other chronic underlying lung disease is not recommended.

Caution and observation is recommended when treating patients with carbidopa, as depression with concomitant suicidal tendencies may develop or be exacerbated.

The use of levodopa, especially in combinations with carbidopa, has been associated with an increase in the frequency of gastrointestinal hemorrhage. Therapy with levodopa should be administered cautiously in patients with a history of peptic ulcer disease or gastrointestinal hemorrhage.