MetoprololNursing considerations

Side effects by what to assess

Sources: [1][2][3][4][5]

Blood glucose

Why

Hypoglycemia that beta blockade can mask

When

In diabetes, fasting, or vomiting

Normal

Fasting 70 to 99 mg/dL.

Sources: [1][2]

Blood pressure

Why

Response and hypotension

When

Near the end of the dosing interval, weekly during titration

Act on

Contraindicated with systolic BP below 100 mm Hg

Normal

Below 120/80 mm Hg.

Sources: [1][2][3]

Body weight

Why

Fluid gain from worsening heart failure during titration

When

During up-titration in heart failure

Act on

Worsening heart failure: raise diuretics and hold the dose increase

Sources: [1]

Heart rate

Why

Bradycardia and titration endpoint

When

Before dose increases, weekly during titration

Act on

Contraindicated in severe bradycardia; in heart failure, lower the dose for symptomatic bradycardia

Normal

60 to 100 beats per minute in adults at rest.

Sources: [1][2][3][4]

High-alert status

Oral metoprolol is not on the ISMP acute care list. IV adrenergic antagonists, including IV metoprolol, are on it.

Sources: [1]

Narrow therapeutic index

The label does not describe a narrow therapeutic index or direct dosing by measured blood levels of the drug.

Sources: [1][2]

Boxed warning

None on the current Lopressor or Toprol-XL labels. Abrupt cessation is a labeled warning instead.

Sources: [1][2]

Antidote or reversal

No single antidote. Treat bradycardia with atropine, adrenergic drugs, or pacing; hypotension with vasopressors such as norepinephrine; heart failure or shock with fluids, glucagon, and dobutamine; and bronchospasm with bronchodilators. Hemodialysis does not help.

Sources: [1]

Patient teaching

• Take it every day as directed, with or right after meals for the tartrate form
• If a dose is missed, take only the next scheduled dose; never double up
• Do not stop suddenly without talking to the prescriber
• Avoid driving or hazardous tasks until you know how it affects you
• Call the prescriber about any trouble breathing
• Tell the surgeon or dentist you take metoprolol
• Hypoglycemia risk rises when fasting or vomiting, and the usual racing-heart warning may not appear

Sources: [1][2]

Sound-alike and look-alike names

• metoprolol succinate and metoprolol tartrate
• Lopressor and Lyrica
• Toprol-XL and Topamax

Sources: [1]

Adult dose

Hypertension, tartrate

100 mg daily in 1 or 2 doses to start. Effective range 100 to 450 mg per day; titrate weekly. Once-daily low doses may wear off before 24 hours.

Hypertension, succinate

25 to 100 mg once daily to start; titrate weekly. Doses above 400 mg per day have not been studied.

Angina

Tartrate: 100 mg daily in 2 doses, range 100 to 400 mg per day. Succinate: 100 mg once daily, up to 400 mg per day studied.

Acute MI, tartrate

If full IV metoprolol was tolerated: 50 mg every 6 hours for 48 hours, starting 15 minutes after the last IV dose (25 mg if not tolerated). Then 100 mg twice daily for at least 3 months.

Heart failure, succinate

25 mg once daily for NYHA class II or 12.5 mg for more severe failure. Double every 2 weeks as tolerated, up to 200 mg.

Sources: [1][2][3][4][5][6]

Renal adjustment

None. Bioavailability and half-life are not meaningfully changed in renal failure.

Sources: [1]

Hepatic adjustment

Start below the usual dose and increase gradually. Metoprolol is cleared by the liver, so levels may rise substantially when hepatic function is poor.

Sources: [1]

Mechanism

Blocks beta-1 receptors in the heart, which slows the sinus rate and AV node conduction and reduces cardiac output. Selectivity is relative: at higher levels it also blocks beta-2 receptors in the airways and blood vessels. It has no intrinsic sympathomimetic activity.

Sources: [1]