DOSAGE AND ADMINISTRATION
DOSAGE MUST BE INDIVIDUALIZED, AS DETERMINED BY TITRATION OF THE INDIVIDUAL COMPONENTS (see box warning). Once the patient has been successfully titrated, ALDOCLOR may be substituted if the previously determined titrated doses are the same as in the combination. The usual starting dosage is one tablet of ALDOCLOR 250 two or three times a day.
When administered individually, the usual daily dosage of chlorothiazide is 0.5 g to 1.0 g in single or divided doses and that of methyldopa is 500 mg to 2 g. To minimize the sedation associated with methyldopa, start dosage increases in the evening.
Occasionally tolerance to methyldopa may occur, usually between the second and third month of therapy. Additional separate doses of methyldopa or replacement of ALDOCLOR with single entity agents is necessary until the new effective dose ratio is re-established by titration. The maximum recommended daily dose of methyldopa is 3 g. When ALDOCLOR 250 is used to provide 1 g of methyldopa, 1 g of chlorothiazide is delivered. It is prudent, if greater than 1 g of methyldopa per day is required, to provide the additional methyldopa as methyldopa alone.
If ALDOCLOR does not adequately control blood pressure, additional doses of other agents may be given. When ALDOCLOR is given with antihypertensives other than thiazides, the initial dosage of methyldopa should be limited to 500 mg daily in divided doses and the dose of these other agents may need to be adjusted to effect a smooth transition.
Since both components of ALDOCLOR have a relatively short duration of action, withdrawal is followed by return of hypertension usually within 48 hours. This is not complicated by an overshoot of blood pressure.
Since methyldopa is largely excreted by the kidney, patients with impaired renal function may respond to smaller doses. Syncope in older patients may be related to an increased sensitivity and advanced arteriosclerotic vascular disease. This may be avoided by lower doses.
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