Posology : מינונים

4.2 Posology and method of administration
Posology
The optimum daily dosage of Dopicar must be determined by careful titration in each patient.
Dopicar Tablets are available in a ratio of 1:10 of carbidopa to levodopa Most patients can be maintained on 3-6 tablets of Dopicar a day, given in divided doses.
The maximum dosage should not exceed 8 tablets of Dopicar a day, since experience with total daily dosages of carbidopa greater than 200 mg is limited. If further titration of dosage is desired, levodopa should be added to the treatment regimen.
General considerations
Studies show that the peripheral dopa-decarboxylase is fully inhibited (saturated) by carbidopa at doses between 70 and 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting. Patients who require only low doses of levodopa (e.g. less than 700 mg when given as Dopicar), will receive doses of carbidopa which theoretically do not saturate peripheral dopa decarboxylase.
Standard antiparkinsonian drugs, other than levodopa alone, may be continued while Dopicar is being administered, although their dosage may have to be adjusted.
Because both therapeutic and adverse effects are seen more rapidly with Dopicar than with levodopa, patients should be carefully monitored during the dosage adjustment period. Involuntary movements, particularly blepharospasm, are a useful early sign of excess dosage in some patients.
Patients not currently receiving levodopa
Dosage may be best initiated with half tablet of Dopicar 3 times a day and increased by half a tablet every day or every other day, until a dosage of 3 tablets a day is reached.
If further titration is necessary, dosage with Dopicar may be increased by half or one tablet every day or every other day, to a maximum of 8 tablets a day. Alternatively, dosage may be titrated to 6 tablets of Dopicar a day, and further adjusted with increments of levodopa.
Because both therapeutic and adverse responses occurmore rapidly with Dopicar than when levodopa is administered, patients should be monitored closely during the dosage adjustment period. Specifically, involuntary movements will occur more rapidly with Dopicar than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.
Patients receiving levodopa
Levodopa must be discontinued at least 12 hours before Dopicar therapy is initiate. The easiest way to move patients from therapy with levodopa to Dopicar is to initiate Dopicar as the first morning dose, after a night without any levodopa. The daily dosage of Dopicar chosen should provide approximately 25% of the previous levodopa daily dosage.
The suggested starting dosage for most patients is one tablet of Dopicar, 3 or 4 times a day.
Patients who require less than 1,500 mg levodopa a day should be started on half tablet of Dopicar, 3 or 4 times a day. Adjustment in dosage may be made as necessary, by adding or omitting half-one tablet a day.
Maintenance
Experience with a total daily dosage greater than 200 mg carbidopa is limited.
If general anesthesia is required, therapy with Dopicar may be continued as long as the patient is permitted to take fluids and medication orally. If therapy is interrupted temporarily, the usual daily dosage may be administered as soon as the patient is able to take oral medication.
Patients receiving levodopa with another decarboxylase inhibitor
When transferring a patient to Dopicar from levodopa combined with another decarboxylase inhibitor, discontinue dosage at least 12 hours (for instant release formulations) or 24 hours (for sustained release formulations) before Dopicar is started. Begin with a dosage of Dopicar that will provide the same amount of levodopa as contained in the other levodopa/decarboxylase inhibitor combination.
Patients receiving other antiparkinsonian agents
Current evidence indicates that other antiparkinsonian agents may be continued when Dopicar is introduced, although dosage may have to be adjusted in line with manufacturers recommendations.
Paediatric population
The safety of Dopicar in patients under 18 years of age has not been established and its use in patients below the age of 18 is not recommended.


Elderly
There is wide experience in the use of this product in elderly patients. The recommendations set out above reflect the clinical data derived from this experience.
Method of administration
To be taken orally.