Metoprolol Tartrate
Metoprolol Tartrate (中文：美托洛爾)
Pronunciation
Metoprolol tartrate 100mg
Metoprolol tartrate 50mg
Common Strengths of Metoprolol
Metoprolol is available in the following strengths:
- Immediate-release tablets (Metoprolol tartrate): 25mg, 50mg, 100mg [1]
- Extended-release tablets (metoprolol succinate): 25mg, 50mg, 100mg, 200mg [1]
Drug trade name of Metoprolol
The brand names for metoprolol include:
- Lopressor (immediate-release metoprolol tartrate tablets)
- Betaloc Zok (extended-release metoprolol succinate tablets) [1]
Mechanism of Action
Metoprolol is a β1-selective (cardioselective) beta-blocker. It works by blocking the action of epinephrine (adrenaline) on beta-1 receptors in the heart. This slows the heart rate, reduces force of heart contractions, oxygen demand and decreases blood pressure. [1][2]
Route of Administration
Metoprolol is available for:
- Oral administration as immediate-release and extended-release tablets
- Intravenous injection (given by healthcare providers) [1][3]
Dosages
- Hypertension
- Immediate-release: Typical starting 50 mg once daily, up to 400 mg/day maximum
- Extended-release: Typical starting 100 mg once daily, up to 400 mg/day maximum [1]
- Heart failure: dosage not specified
- Immediate-release: Typical 25-100 mg twice daily
- Extended-release: Typical 25-200 mg once daily [2]
- Diabetic kidney disease: Dosage not specified, adjust based on patient response.
Side Effects
| Frequency | Adverse reactions |
|---|---|
| Very common (≥1/10) | Bradycardia (slow heart rate) |
| Common (≥1/100 to <1/10) | Dizziness |
| Fatigue | |
| Memory problems | |
| Diarrhea [1][3] | |
| Uncommon (≥1/1,000 to <1/100) | Depression |
| Confusion | |
| Insomnia | |
| Rash [3] | |
| Rare (≥1/10,000 to <1/1,000) | Nightmares [3] |
Pharmacokinetics
- Well absorbed from GI tract
- Peak plasma levels in 2-4 hours
- Extensively metabolized in liver
- Elimination half-life 6-7 hours
- Excreted in urine [2]
Drug Management
Safety
Metoprolol has a boxed warning about not stopping it suddenly, as it may worsen chest pain, increase blood pressure, or cause a heart attack. Stopping should be done gradually under medical supervision.[1]
Contraindicated in heart block, sick sinus syndrome, severe bradycardia, severe circulation problems, severe heart failure.
Caution in asthma, COPD, diabetes, liver disease. [1][3]
Pregnancy
Metoprolol is classified as pregnancy category C. It should only be used if the potential benefit justifies the potential risk to the fetus.[3]
Breastfeeding
Present in breast milk at low levels. Caution advised as it may cause effects in infant. [3]
Children and Elderly
- Children: Dosage not established
- Elderly: May need lower doses due to age-related decreased kidney function
Renal Impairment
No dosage adjustment provided in labeling. Use with caution in severe renal impairment. [3]
Monitoring Requirements
Monitor blood pressure, heart rate, signs of worsening heart failure, bronchospasm, and blood glucose levels (in diabetics) during metoprolol therapy. [3][2]
Drug Interactions
Metoprolol can interact with calcium channel blockers, digoxin, epinephrine (adrenaline), antidepressants, antipsychotics, anesthetics, and many other drugs. Careful monitoring is required. [1][3]
FAQs
How should I take the tablet?
Take orally with or without food as prescribed. Swallow extended-release capsules whole. [3]
What should I avoid while taking?
Avoid driving or hazardous tasks until you know how metoprolol affects you. Avoid alcohol and decongestants as these may increase some side effects. [3]
What happens if I miss a dose?
Take the missed dose as soon as you remember. If it's near the next dose time, skip the missed dose and continue your regular schedule. Do not double the dose. [3]
Reference
[1] https://www.medicalnewstoday.com/articles/metoprolol-oral-tablet
[2] https://www.drugs.com/metoprolol.thml
[3] https://go.drugbank.com/drugs/DB00264
[4] https://www.ncbi.nlm.nih.gov/books/NBK532923/
[5] https://www.webmd.com/drugs/2/drug-11207/metoprolol-tartrate-oral/details
