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TRANDATE®
(labetalol hydrochloride) Tablets

DESCRIPTION

Trandate (labetalol) Tablets are adrenergic receptor blocking agents that have both selective alpha1-adrenergic and nonselective beta-adrenergic receptor blocking actions in a single substance.

Labetalol hydrochloride (HCl) is a racemate chemically designated as 2-hydroxy-5-[1-hydroxy-2-[(1methyl-3-phenylpropyl)amino]ethyl]benzamide monohydrochloride, and it has the following structure:

Labetalol HCl has the empirical formula C19H24N2O3•HCl and a molecular weight of 364.9. It has two asymmetric centers and therefore exists as a molecular complex of two diastereoisomeric pairs. Dilevalol, the R,R' stereoisomer, makes up 25% of racemic labetalol.

Labetalol HCl is a white or off-white crystalline powder, soluble in water.

Trandate Tablets contain 100, 200, or 300 mg of labetalol HCl and are taken orally. The tablets also contain the inactive ingredients corn starch, FD&C Yellow No. 6 (100- and 300-mg tablets only), hydroxypropyl methylcellulose, lactose, magnesium stearate, pregelatinized corn starch, sodium benzoate (200-mg tablet only), talc (100-mg tablet only), and titanium dioxide.

INDICATIONS

Trandate (labetalol) Tablets are indicated in the management of hypertension. Trandate (labetalol) Tablets may be used alone or in combination with other antihypertensive agents, especially thiazide and loop diuretics.

DOSAGE AND ADMINISTRATION

DOSAGE MUST BE INDIVIDUALIZED. The recommended initial dosage is 100 mg twice daily whether used alone or added to a diuretic regimen. After 2 or 3 days, using standing blood pressure as an indicator, dosage may be titrated in increments of 100 mg b.i.d. every 2 or 3 days. The usual maintenance dosage of labetalol HCl is between 200 and 400 mg twice daily.

Since the full antihypertensive effect of labetalol HCl is usually seen within the first 1 to 3 hours of the initial dose or dose increment, the assurance of a lack of an exaggerated hypotensive response can be clinically established in the office setting. The antihypertensive effects of continued dosing can be measured at subsequent visits, approximately 12 hours after a dose, to determine whether further titration is necessary.

Patients with severe hypertension may require from 1,200 to 2,400 mg per day, with or without thiazide diuretics. Should side effects (principally nausea or dizziness) occur with these doses administered twice daily, the same total daily dose administered three times daily may improve tolerability and facilitate further titration. Titration increments should not exceed 200 mg twice daily.

When a diuretic is added, an additive antihypertensive effect can be expected. In some cases this may necessitate a labetalol HCl dosage adjustment. As with most antihypertensive drugs, optimal dosages of Trandate (labetalol) Tablets are usually lower in patients also receiving a diuretic.

When transferring patients from other antihypertensive drugs, Trandate (labetalol) Tablets should be introduced as recommended and the dosage of the existing therapy progressively decreased.

Elderly Patients

As in the general patient population, labetalol therapy may be initiated at 100 mg twice daily and titrated upwards in increments of 100 mg b.i.d. as required for control of blood pressure. Since some elderly patients eliminate labetalol more slowly, however, adequate control of blood pressure may be achieved at a lower maintenance dosage compared to the general population. The majority of elderly patients will require between 100 and 200 mg b.i.d.

HOW SUPPLIED

Trandate (labetalol) Tablets, 100 mg, light orange, round, scored, film-coated tablets engraved on one side with “TRANDATE (labetalol) 100,” bottles of 100 (NDC 65483-391-10) and 500 (NDC 65483-391-50) and unit dose packs of 100 tablets (NDC 65483-391-11).

Trandate (labetalol) Tablets, 200 mg, white, round, scored, film-coated tablets engraved on one side with “TRANDATE (labetalol) 200,” bottles of 100 (NDC 65483-392-10) and 500 (NDC 65483-392-50) and unit dose packs of 100 tablets (NDC 65483-392-22).

Trandate (labetalol) Tablets, 300 mg, mid-orange, round, scored, film-coated tablets engraved on one side with “TRANDATE (labetalol) 300,” bottles of 100 (NDC 65483-393-10) and 500 (NDC 65483-393-50) and unit dose packs of 100 tablets (NDC 65483-393-33).

Trandate (labetalol) Tablets should be stored between 2° and 30°C (36° and 86°F). Trandate (labetalol) Tablets in the unit dose boxes should be protected from excessive moisture.

Prometheus Laboratories Inc. Manufactured in Canada by WellSpring Pharmaceutical Canada Corp. Oakville, ON L6H 1M5 for Prometheus Laboratories Inc. San Diego, CA 92121. Revised: November 2010

SIDE EFFECTS

Most adverse effects are mild and transient and occur early in the course of treatment. In controlled clinical trials of 3 to 4 months' duration, discontinuation of Trandate (labetalol) Tablets due to one or more adverse effects was required in 7% of all patients. In these same trials, other agents with solely beta-blocking activity used in the control groups led to discontinuation in 8% to 10% of patients, and a centrally acting alpha-agonist led to discontinuation in 30% of patients.

The incidence rates of adverse reactions listed in the following table were derived from multicenter, controlled clinical trials comparing labetalol HCl, placebo, metoprolol, and propranolol over treatment periods of 3 and 4 months. Where the frequency of adverse effects for labetalol HCl and placebo is similar, causal relationship is uncertain. The rates are based on adverse reactions considered probably drug related by the investigator. If all reports are considered, the rates are somewhat higher (e.g., dizziness, 20%; nausea, 14%; fatigue, 11%), but the overall conclusions are unchanged.