DOSAGE AND ADMINISTRATION
Individual tablets should not be fractionated and only one tablet should be administered at each dosing interval.
Generally speaking, Stalevo® (carbidopa, levodopa and entacapone) should be used as a substitute for patients already stabilized on equivalent doses of carbidopa-levodopa and entacapone. However, some patients who have been stabilized on a given dose of carbidopa-levodopa may be treated with Stalevo if a decision has been made to add entacapone (see below).
The optimum daily dosage of Stalevo must be determined by careful titration in each patient. Stalevo tablets are available in three strengths, each in a 1:4 ratio of carbidopa to levodopa and combined with 200 mg of entacapone in a standard-release formulation (Stalevo 50 containing 12.5 mg of carbidopa, 50 mg of levodopa and 200 mg of entacapone; Stalevo 100 containing 25 mg of carbidopa, 100 mg of levodopa and 200 mg of entacapone; and Stalevo 150 containing 37.5 mg of carbidopa, 150 mg of levodopa and 200 mg of entacapone).
Therapy should be individualized and adjusted according to the desired therapeutic response.
Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 mg to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting. Experience with total daily dosages of carbidopa greater than 200 mg is limited.
Clinical experience with daily doses above 1600 mg of entacapone is limited. It is recommended that no more than one Stalevo tablet be taken at each dosing administration. Thus the maximum recommended daily dose of Stalevo is eight tablets per day.
HOW TO TRANSFER PATIENTS TAKING CARBIDOPA-LEVODOPA PREPARATIONS AND COMTAN® (ENTACAPONE) TABLETS TO STALEVO®(CARBIDOPA, LEVODOPA AND ENTACAPONE) TABLETS
There is no experience in transferring patients currently treated with formulations of carbidopa-levodopa other than immediate-release carbidopa-levodopa with a 1:4 ratio (controlled-release formulations, or standard-release presentations with a 1:10 ratio of carbidopa-levodopa) and entacapone to Stalevo.
Patients who are currently treated with Comtan 200 mg tablet with each dose of standard-release carbidopa-levodopa, can be directly switched to the corresponding strength of Stalevo containing the same amounts of levodopa and carbidopa. For example, patients receiving one tablet of standard-release carbidopa-levodopa 25/100 mg and one tablet of Comtan 200 mg at each administration can be switched to a single Stalevo 100 tablet (containing 25 mg of carbidopa, 100 mg of levodopa and 200 mg of entacapone).
HOW TO TRANSFER PATIENTS NOT CURRENTLY TREATED WITH COMTAN® (ENTACAPONE) TABLETS FROM CARBIDOPA-LEVODOPA TO STALEVO®(CARBIDOPA, LEVODOPA AND ENTACAPONE) TABLETS
In patients with Parkinson's disease who experience the signs and symptoms of end-of-dose "wearing-off" on their current standard-release carbidopa-levodopa treatment, clinical experience shows that patients with a history of moderate or severe dyskinesias or taking more than 600 mg of levodopa per day are likely to require a reduction in daily levodopa dose when entacapone is added to their treatment. Since dose adjustment of the individual components is impossible with fixed-dose products, it is recommended that patients first be titrated individually with a carbidopa-levodopa product (ratio 1:4) and an entacapone product, and then transferred to a corresponding dose of Stalevo once the patient's status has stabilized.
In patients who take a total daily levodopa dose up to 600 mg, and who do not have dyskinesias, an attempt can be made to transfer to the corresponding daily dose of Stalevo. Even in these patients, a reduction of carbidopa-levodopa or entacapone may be necessary however, the provider is reminded that this may not be possible with Stalevo. Since entacapone prolongs and enhances the effects of levodopa, therapy should be individualized and adjusted if necessary according to the desired therapeutic response.
MAINTENANCE OF STALEVO®TREATMENT
Therapy should be individualized and adjusted for each patient according to the desired therapeutic response.
When less levodopa is required, the total daily dosage of carbidopa-levodopa should be reduced by either decreasing the strength of Stalevo at each administration or by decreasing the frequency of administration by extending the time between doses.
When more levodopa is required, the next higher strength of Stalevo should be taken and/or the frequency of doses should be increased, up to a maximum of 8 times daily and not to exceed the maximum daily dose recommendations as outlined above.
ADDITION OF OTHER ANTIPARKINSONIAN MEDICATIONS
Standard drugs for Parkinson's disease may be used concomitantly while Stalevo is being administered, although dosage adjustments may be required.
INTERRUPTION OF THERAPY
Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of levodopa preparations. Patients should be observed carefully if abrupt reduction or discontinuation of Stalevo is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)
If general anesthesia is required, Stalevo may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.
SPECIAL POPULATIONS
PATIENTS WITH IMPAIRED HEPATIC FUNCTION
Patients with hepatic impairment should be treated with caution. The AUC and Cmax of entacapone approximately doubled in patients with documented liver disease, compared to controls. However, these studies were conducted with single-dose entacapone without levodopa/dopa decarboxylase inhibitor coadministration, and therefore the effects of liver disease on the kinetics of chronically administered entacapone have not been evaluated (see CLINICAL PHARMACOLOGY, Pharmacokinetics of Entacapone).
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