Patients Receiving Carbidopa-Levodopa Who Require Additional Carbidopa

Some patients taking carbidopa-levodopa may not have adequate reduction in nausea and

vomiting when the dosage of carbidopa is less than 70 mg a day, and the dosage of levodopa

is less than 700 mg a day. When these patients are taking carbidopa-levodopa, 25 mg of LODOSYN may be given with the first dose of carbidopa-levodopa each day. Additional doses of 12.5 mg or 25 mg may be given during the day with each dose of carbidopa-levodopa. LODOSYN may be given with any dose of carbidopa-levodopa as required for optimum therapeutic response. The maximum daily dosage of carbidopa, given as LODOSYN

and as carbidopa-levodopa, should not exceed 200 mg.

Patients Requiring Individual Titration of Carbidopa and Levodopa Dosage

Although carbidopa-levodopa is the most frequently used of carbidopa and levodopa

administration, there may be an occasional patient who requires individually titrated doses of

these two drugs. In these patients, LODOSYN (carbidopa) should be initiated at a dosage

of 25 mg three or four times a day. The two drugs should be given at the same time,

starting with no more than one-fifth (20%) to one-fourth (25%) of the previous or

recommended daily dosage of levodopa when given without LODOSYN (carbidopa). In

patients already receiving levodopa therapy, at least twelve hours should elapse between

the last dose of levodopa and initiation of therapy with LODOSYN (carbidopa) and

levodopa. A convenient way to initiate therapy in these patients is in the morning

following a night when the patient has not taken levodopa for at least twelve hours.

Health care providers who prescribe separate doses of LODOSYN and levodopa should be

thoroughly familiar with the directions for use of each drug.

Dosage Adjustment

Dosage of LODOSYN may be adjusted by adding or omitting one-half or one tablet a day. Because both therapeutic and adverse responses occur more rapidly with combined therapy than when only levodopa is given, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly when LODOSYN and levodopa are given concomitantly than when levodopa is given without LODOSYN. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Current evidence indicates other standard antiparkinsonian drugs may be continued while carbidopa and levodopa are being administered. However, the dosage of such other standard antiparkinsonian drugs

may require adjustment.

Interruption of Therapy

Sporadic cases of hyperpyrexia and confusion have been associated with dose reductions and

withdrawal of carbidopa-levodopa) or carbidopa-levodopa extended release. Patients should

be observed carefully if abrupt reduction or discontinuation of carbidopa-levodopa or

carbidopa-levodopa extended release is required, especially if the patient is receiving

neuroleptics. (See WARNINGS.)

If general anesthesia is required, therapy may be continued as long as the patient is permitted to take fluids and medication by mouth. When therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be resumed as soon as the patient is able to take medication orally.