Metoprolol Tartrate
Pronunciation
Metoprolol tartrate 100mg
Metoprolol tartrate 50mg
| Generic Name: | Metoprolol Tartrate, Metoprolol succinate |
|---|---|
| Class: | Cardiovascular Drug |
| Subclass: | Beta blocker |
Common Strengths of Metoprolol
Metoprolol is available in the following strengths:
- Immediate-release tablets (Metoprolol tartrate): 25mg, 37.5mg, 50mg, 75mg, 100mg [1]
- Extended-release tablets (metoprolol succinate): 25mg, 50mg, 100mg, 200mg [1]
Drug Name
| Generic Name 藥物化學名稱 | Brand Name |
|---|---|
| Metoprolol Tartrate Tablet 50mg | LOPRESSOR |
| Metoprolol Tartrate Tablet 100mg | |
| Metoprolol Succinate Tablet 25mg | BETALOC ZOK [1] |
| Metoprolol Succinate Tablet 50mg | |
| Metoprolol Succinate Tablet 100mg | |
| Metoprolol Succinate Tablet 200mg |
Mechanism of Action
Metoprolol is a β1-selective (cardio-selective) 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]
Route of Administration
Metoprolol is available for:
- Oral administration as immediate-release and extended-release tablets
- Intravenous injection (given by healthcare providers) [1]
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
- Diabetic kidney disease: Dosage not specified, adjust based on patient response.
Side Effects
The following definitions of frequencies are used:
Very common ≥ 1/10
Common ≥ 1/100 to < 1/10
Uncommon ≥1/1,000 to <1/100
Rare ≥ 1/10,000 to < 1/1,000
Very rare < 1/10,000
| Frequency | Adverse reactions |
|---|---|
| Very common | Bradycardia (slow heart rate) |
| Common | Dizziness |
| Fatigue | |
| Memory problems | |
| Diarrhea [1] | |
| Uncommon | Depression |
| Confusion | |
| Insomnia | |
| Rash | |
| Rare | Nightmares |
Pharmacokinetics
- Well absorbed from GI tract
- Extensively metabolized in liver
- Elimination half-life 6-7 hours
- Excreted in urine
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]
Pregnancy
Metoprolol is classified as pregnancy category C. It should only be used if the potential benefit justifies the potential risk to the fetus.
Breastfeeding
Present in breast milk at low levels. Caution advised as it may cause effects in infant.
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.
Monitoring Requirments
Monitor blood pressure, heart rate, signs of worsening heart failure, bronchospasm, and blood glucose levels (in diabetics) during metoprolol therapy.
Drug Interactions
Metoprolol can interact with calcium channel blockers, digoxin, epinephrine (adrenaline), antidepressants, antipsychotics, anesthetics, and many other drugs. Careful monitoring is required. [1]
FAQs
How should I take the tablet?
Take orally with or without food as prescribed. Swallow extended-release capsules whole.
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.
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.
