• Hypertension.
• Angina pectoris.
• Prevention of MI and decreased mortality in patients with recent MI.
• Stable, symptomatic (class II or III) heart failure due to ischemic, hypertensive, or cardiomyopathic origin (Toprol XL only).

Unlabeled Uses:

• Ventricular arrhythmias/tachycardia.
• Migraine prophylaxis.
• Tremors.
• Aggressive behavior.
• Drug-induced akathisia.
• Anxiety.

Contraindicated in:

• Uncompensated HF
• Pulmonary edema
• Cardiogenic shock
• Bradycardia, heart block, or sick sinus syndrome (in absence of a pacemaker).

Use Cautiously in:

• Renal impairment
• Hepatic impairment
• Pulmonary disease (including asthma; beta₁ selectivity may be lost at higher doses)
• Diabetes mellitus or patients with ↓ nutritional intake (may mask signs of hypoglycemia)
• Thyrotoxicosis (may mask symptoms)
• History of severe allergic reactions (intensity of reactions may be ↑)
• Untreated pheochromocytoma (initiate only after alpha blocker therapy started)
• OB: Use during pregnancy only if potential maternal benefit justifies potential fetal risk
• Lactation: Use while breastfeeding only if potential maternal benefit justifies potential risk to infant; may result in bradycardia, constipation, diarrhea, and dry mouth/skin/eyes in infant, especially in mothers who are CYP2D6 poor metabolizers.
• Pedi: Safety and effectiveness not established in children <18 yr (tablets, extended-release tablets, and injection) or <6 yr (extended-release capsules)
• Geri: Older adults may have ↑ sensitivity to beta blockers; initial dose ↓ recommended.

CV: BRADYCARDIA, heart block, HF, hypotension, peripheral vasoconstriction.

Derm: rash.

EENT: blurred vision, stuffy nose.

Endo: hyperglycemia, hypoglycemia.

GI: ↑liver enzymes, constipation, diarrhea, drug-induced hepatitis, dry mouth, flatulence, gastric pain, heartburn, nausea, vomiting.

GU: erectile dysfunction, ↓ libido, urinary frequency.

MS: arthralgia, back pain, joint pain.

Neuro: fatigue, weakness, anxiety, depression, dizziness, drowsiness, insomnia, memory loss, mental status changes, nervousness, nightmares.

Resp: bronchospasm, PULMONARY EDEMA, wheezing.
Misc: drug-induced lupus syndrome.

Drug-Drug:

• General anesthesia, IVphenytoin, and verapamil may cause ↑ myocardial depression.
• ↑risk of bradycardia when used with digoxin, verapamil, diltiazem, or clonidine.
• ↑hypotension may occur with other antihypertensives, acute ingestion of alcohol, or nitrates.
• Concurrent use with amphetamines, cocaine, ephedrine, epinephrine, norepinephrine, phenylephrine, or pseudoephedrine may result in unopposed alpha-adrenergic stimulation (excessive hypertension, bradycardia).
• Concurrent administration of thyroid administration may ↓ effectiveness.
• May alter the effectiveness of insulins or oral hypoglycemic agents (dose adjustments may be necessary).
• May ↓ the effectiveness of theophylline.
• May ↓ the beneficial beta₁-cardiovascular effects of dopamine or dobutamine.
• Use cautiously within 14 days of MAO inhibitor therapy (may result in hypertension).

(Generic available)

• Tablets (tartrate): 25 mg; 37.5 mg; 50 mg; 75 mg; 100 mg;
• Extended-release capsules (succinate; Kapspargo Sprinkle): 25 mg; 50 mg; 100 mg; 200 mg;
• Extended-release tablets (succinate; Toprol XL): 25 mg; 50 mg; 100 mg; 200 mg;
• Solution for injection: 1 mg/mL;
• In combination with: hydrochlorothiazide (Lopressor HCT). See Appendix [not included in this PDA edition].

When switching from immediate-release to extended-release product, the same total daily dose can be used

• PO (Adults): Hypertension/angina: 25–100 mg/day as a single dose initially or 2 divided doses; may be ↑ every 7 days as needed up to 450 mg/day (immediate-release) or 400 mg/day (extended-release) (for angina, give in divided doses). Extended-release products are given once daily. MI: 25–50 mg (starting 15 min after last IV dose) every 6 hr for 48 hr, then 100 mg twice daily. Heart failure: 12.5–25 mg once daily (of extended-release), can be doubled every 2 wk up to 200 mg/day. Migraine prevention: 50–100 mg 2–4 times daily (unlabeled).
• IV (Adults): MI: 5 mg every 2 min for 3 doses, followed by oral dosing.
• PO (Children 6 yr): Hypertension: 1 mg/kg once daily (extended-release capsules); may be titrated, as needed (not to exceed 50 mg/day).

Kapspargo Sprinkle, Lopressor, Toprol XL

• Blocks stimulation of beta₁(myocardial)-adrenergic receptors. Does not usually affect beta₂(pulmonary, vascular, uterine)-adrenergic receptor sites.

• Decreased BP and heart rate.
• Decreased frequency of attacks of angina pectoris.
• Decreased rate of cardiovascular mortality and hospitalization in patients with heart failure.

Therapeutic Classification: antianginals, antihypertensives

Pharmacologic Classification: beta blockers

Absorption: Well absorbed after oral administration.

Distribution: Crosses the blood-brain barrier, crosses the placenta; small amounts enter breast milk.

Metabolism/Excretion: Mostly metabolized by the liver via the CYP2D6 isoenzyme; the CYP2D6 isoenzyme exhibits genetic polymorphism; 7% of population may be poor metabolizers and may have significantly ↑ metoprolol concentrations and an ↑ risk of adverse effects.

Half-life: 3–7 hr.

(cardiovascular effects)

†Maximal effects on BP (chronic therapy) may not occur for 1 wk. Hypotensive effects may persist for up to 4 wk after discontinuation.

• Instruct patient to take medication as directed, at the same time each day, even if feeling well; do not skip or double up on missed doses. Take missed doses as soon as possible up to 8 hr before next dose. Abrupt withdrawal may precipitate life-threatening arrhythmias, hypertension, or myocardial ischemia.
• Teach patient and family how to check pulse daily and BP biweekly and to report significant changes to health care professional.
• May cause drowsiness. Caution patient to avoid driving or other activities that require alertness until response to the drug is known.
• Advise patient to change positions slowly to minimize orthostatic hypotension.
• Caution patient that this medication may increase sensitivity to cold.
• Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking any Rx, OTC, or herbal products, especially cold preparations, concurrently with this medication. Patients on antihypertensive therapy should also avoid excessive amounts of coffee, tea, and cola.
• Diabetics should closely monitor blood glucose, especially if weakness, malaise, irritability, or fatigue occurs. Medication does not block sweating as a sign of hypoglycemia.
• Advise patient to notify health care professional if slow pulse, difficulty breathing, wheezing, cold hands and feet, dizziness, light-headedness, confusion, depression, rash, fever, sore throat, unusual bleeding, or bruising occurs.
• Instruct patient to inform health care professional of medication regimen before treatment or surgery.
• Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected, or if breastfeeding. Monitor neonates of women taking metoprolol for symptoms of hypotension, bradycardia, hypoglycemia, and respiratory depression and manage accordingly. Monitor breastfed infants for bradycardia, dry mouth, skin or eyes, and diarrhea or constipation.
• Advise patient to carry identification describing disease process and medication regimen at all times.
• Hypertension: Reinforce the need to continue additional therapies for hypertension (weight loss, sodium restriction, stress reduction, regular exercise, moderation of alcohol consumption, and smoking cessation). Medication controls but does not cure hypertension.

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