Labetalol: uses, appearance and warnings

Labetalol hydrochloride tablets, USP are indicated in the management of hypertension. Labetalol hydrochloride tablets USP may be used alone or in combination with other antihypertensive agents, especially thiazide and loop diuretics.

Labetalol Hydrochloride Tablets, USP for oral administration are available as: Labetalol Hydrochloride Tablets USP, 100 mg are yellow colored, round, biconvex, film-coated tablets debossed with "7" and "98" on either side of score line on one side and plain on other side and are supplied as: NDC 68001-381-00 in bottle of 100 tablets NDC 68001-381-03 in bottle of 500 tablets Labetalol Hydrochloride Tablets USP, 200 mg are white to off white colored, round, biconvex, film-coated tablets debossed with "7" and "99" on either side of score line on one side and plain on other side and are supplied as: NDC 68001-382-00 in bottle of 100 tablets NDC 68001-382-03 in bottle of 500 tablets Labetalol Hydrochloride Tablets USP, 300 mg are light green colored, round, biconvex, beveled edge, film-coated tablets debossed with "800" on one side and plain on other side and are supplied as: NDC 68001-383-00 in bottle of 100 tablets NDC 68001-383-03 in bottle of 500 tablets Labetalol Hydrochloride Tablets USP should be stored at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature]. Dispense in a tight, light-resistant container as defined in the USP with a child-resistant closure as required. To report SUSPECTED ADVERSE REACTIONS, contact Zydus Pharmaceuticals (USA) Inc. at 1-877-993-8779 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. This product's package insert may have been updated. For current package insert, please visit www.zydususa.com Manufactured by: Zydus Lifesciences Ltd., Ahmedabad, India. For BluePoint Laboratories Rev.: 03/26

Labetalol hydrochloride is contraindicated in bronchial asthma, overt cardiac failure, greater-than-first-degree heart block, cardiogenic shock, severe bradycardia, other conditions associated with severe and prolonged hypotension and in patients with a history of hypersensitivity to any component of the product (see WARNINGS ). Beta-blockers, even those with apparent cardio selectivity, should not be used in patients with a history of obstructive airway disease, including asthma.

Hepatic Injury Severe hepatocellular injury, confirmed by rechallenge in at least one case, occurs rarely with labetalol therapy. The hepatic injury is usually reversible, but hepatic necrosis and death have been reported. Injury has occurred after both short- and long-term treatment and may be slowly progressive despite minimal symptomatology. Similar hepatic events have been reported with a related research compound, dilevalol hydrochloride, including two deaths. Dilevalol hydrochloride is one of the four isomers of labetalol hydrochloride. Thus, for patients taking labetalol, periodic determination of suitable hepatic laboratory tests would be appropriate. Appropriate laboratory testing should be done at the first symptom or sign of liver dysfunction (e.g. pruritus, dark urine, persistent anorexia, jaundice, right upper quadrant tenderness, or unexplained "flu-like" symptoms). If the patient has laboratory evidence of liver injury or jaundice, labetalol should be stopped and not restarted. Cardiac Failure Sympathetic stimulation is a vital component supporting circulatory function in congestive heart failure. Beta-blockade carries a potential hazard of further depressing myocardial contractility and precipitating more severe failure. Although beta-blockers should be avoided in overt congestive heart failure, if necessary, labetalol hydrochloride can be used with caution in patients with a history of heart failure who are well compensated. Congestive heart failure has been observed in patients receiving labetalol hydrochloride. Labetalol hydrochloride does not abolish the inotropic action of digitalis on heart muscle. In Patients Without a History of Cardiac Failure In patients with latent cardiac insufficiency, continued depression of the myocardium with beta-blocking agents over a period of time can, in some cases, lead to cardiac failure. At the first sign or symptom of impending cardiac failure, patients should be fully digitalized and/or be given a diuretic and the response should be observed closely. If cardiac failure continues, despite adequate digitalization and diuretic, therapy with labetalol hydrochloride should be withdrawn (gradually, if possible). Exacerbation of Ischemic Heart Disease Following Abrupt Withdrawal Angina pectoris has not been reported upon labetalol hydrochloride discontinuation. However, hypersensitivity to catecholamines has been observed in patients withdrawn from beta-blocker therapy; exacerbation of angina and, in some cases, myocardial infarction have occurred after abrupt discontinuation of such therapy. When discontinuing chronically administered labetalol hydrochloride, particularly in patients with ischemic heart disease, the dosage should be gradually reduced over a period of 1 week to 2 weeks and the patient should be carefully monitored. If angina markedly worsens or acute coronary insufficiency develops, therapy with labetalol hydrochloride administration should be reinstituted promptly, at least temporarily, and other measures appropriate for the management of unstable angina should be taken. Patients should be warned against interruption or discontinuation of therapy without the physician's advice. Because coronary artery disease is common and may be unrecognized, it may be prudent not to discontinue therapy with labetalol hydrochloride abruptly in patients being treated for hypertension. Non allergic Bronchospasm (e.g. Chronic Bronchitis and Emphysema) Patients with Bronchospastic disease should, in general, not receive beta-blockers . Labetalol hydrochloride may be used with caution, however, in patients who do not respond to, or cannot tolerate, other antihypertensive agents. It is prudent, if labetalol hydrochloride is used, to use the smallest effective dose, so that inhibition of endogenous or exogenous beta-agonists is minimized. Pheochromocytoma Labetalol hydrochloride has been shown to be effective in lowering blood pressure and relieving symptoms in patients with pheochromocytoma. However, paradoxical hypertensive responses have been reported in a few patients with this tumor; therefore, use caution when administering labetalol hydrochloride to patients with pheochromocytoma. Hypoglycemia Beta-blockers may prevent early warning signs of hypoglycemia, such as tachycardia, and increase the risk for severe or prolonged hypoglycemia at any time during treatment, especially in patients with diabetes mellitus or children and patients who are fasting (i.e., surgery, not eating regularly, or are vomiting). If severe hypoglycemia occurs, patients should be instructed to seek emergency treatment. Major Surgery Do not routinely withdraw chronic beta-blocker therapy prior to surgery. The effect of labetalol hydrochloride’s alpha-adrenergic activity has not been evaluated in this setting. A synergism between labetalol hydrochloride and halothane anesthesia has been shown (see PRECAUTIONS , Drug Interactions ).

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 labetalol hydrochloride 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 hydrochloride, placebo, metoprolol and propranolol, over treatment periods of 3 and 4 months. Where the frequency of adverse effects for labetalol hydrochloride and placebo is similar, causal relationship is uncertain. …

In one survey, 2.3% of patients taking labetalol hydrochloride in combination with tricyclic antidepressants experienced tremor as compared to 0.7% reported to occur with labetalol hydrochloride alone. The contribution of each of the treatments to this adverse reaction is unknown but the possibility of a drug interaction cannot be excluded. Drugs possessing beta-blocking properties can blunt the bronchodilator effect of beta-receptor agonist drugs in patients with bronchospasm; therefore, doses greater than the normal anti-asthmatic dose of beta-agonist bronchodilator drugs may be required. Cimetidine has been shown to increase the bioavailability of labetalol hydrochloride. …