Labetalol

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.

• 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. (twice daily) every 2 or 3 days
• The usual maintenance dosage of labetalol hydrochloride tablets is between 200 mg and 400 mg twice daily
• Since the full antihypertensive effect of labetalol hydrochloride tablets 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 1200 mg to 2400 mg per day, with or without thiazide diuretics
• Should side effects (principally nausea or dizziness) occur with these doses administered b.i.d. (twice daily), the same total daily dose administered t.i.d. (three times daily) may improve tolerability and facilitate further titration
• Titration increments should not exceed 200 mg b.i.d. (twice daily)
• When a diuretic is added, an additive antihypertensive effect can be expected
• In some cases this may necessitate a labetalol hydrochloride tablet dosage adjustment
• As with most antihypertensive drugs, optimal dosages of labetalol hydrochloride tablets are usually lower in patients also receiving a diuretic. …

• Safety and effectiveness
• In pediatric patients have not been established

• As with all drugs with beta-blocking activity, certain advice to patients being treated with labetalol hydrochloride is warranted
• This information is intended to aid in the safe and effective use of this medication
• It is not a disclosure of all possible adverse or intended effects
• While no incident of the abrupt withdrawal phenomenon (exacerbation of angina pectoris) has been reported with labetalol hydrochloride, dosing with labetalol hydrochloride should not be interrupted or discontinued without a physician’s advice. …

• 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 cardioselectivity, should not be used in patients with a history of obstructive airway disease, including asthma

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. …

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 HCl, including two deaths. Dilevalol HCl is one of the four isomers of labetalol hydrochloride. Thus, for patients taking labetalol, periodic determination of suitable hepatic laboratory tests would be appropriate. …

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. …

Pregnancy Teratogenic Effects Pregnancy Category C Teratogenic studies were performed with labetalol in rats and rabbits at oral doses up to approximately six and four times the maximum recommended human dose (MRHD), respectively. No reproducible evidence of fetal malformations was observed. Increased fetal resorptions were seen in both species at doses approximating the MRHD. …

Overdosage with labetalol hydrochloride causes excessive hypotension that is posture sensitive and, sometimes, excessive bradycardia. Patients should be placed supine and their legs raised, if necessary, to improve the blood supply to the brain. If overdosage with labetalol hydrochloride follows oral ingestion, gastric lavage or pharmacologically induced emesis (using syrup of ipecac) may be useful for removal of the drug shortly after ingestion. The following additional measures should be employed if necessary: Excessive bradycardia Administer atropine or epinephrine. …

Take it when you remember, unless it is nearly time for the next dose. Then skip the missed one. Never take two doses at once to make up for it. Check your leaflet, as some medicines are different.