Generic name: Metoprolol tartrate.

Other brand names: Toprol XL.

Lopressor is a beta-blocker. It slows the heart rate and reduces high blood pressure. 

Quick Facts About Lopressor


Used to treat high blood pressure, angina pectoris (crushing chest pain), and heart attack. Also occasionally used to treat aggressive behavior, prevent migraines, and relieve temporary anxiety.

Lopressor Dosage

Take with food or immediately after a meal. Continue to take, even if symptoms subside; must take regularly for this medication to be effective. Do not abruptly stop this medication; follow doctor’s instructions for gradual reduction.

  • Usual adult dose: For hypertension — total of 100 milligrams per day taken in 1 or 2 doses, up to 400 milligrams per day. For angina pectoris — total of 100 milligrams per day taken in 2 doses, up to 400 milligrams per day. For heart attack — dosage determined for each individual.
  • Usual child dose: not generally prescribed for children.
  • Missed dose: if within 4 hours of next dose, do not «r take missed dose, go back to regular schedule. Do not double doses.

Lopressor Side Effects

Overdose symptoms:

asthma-like symptoms, heart M failure, low blood pressure, slow heartbeat. If you suspect an overdose, immediately seek medical attention.

More common side effects: depression, diarrhea, dizziness, itching, rash, shortness of breath, slow heartbeat, tiredness.

Less common or rare Lopressor side effects: blurred vision, cold hands and feet, confusion, congestive heart failure, constipation, difficult or labored breathing, dry eyes, dry mouth, gas, hair loss, headache, heart attack, heartburn, low blood pressure, muscle pain, nausea, nightmares, rapid heartbeat, ringing in the ears, short-term memory loss, stomach pain, swelling due to fluid retention, trouble sleeping, wheezing, worsening of heart irregularities.


Inform your doctor before combining Lopressor with:

certain high blood pressure medications such as reserpine (Ser-Ap-Es). Other medications that might interact with Lopressor include: albuterol (Proventil or Ventolin); amiodarone (Cordarone); barbiturates such as phenobarbital; calcium channel blockers such as Calan and Cardizem; cimetidine (Tagamet); ciprofloxacin (Cipro); clonidine (Catapres); epinephrine (EpiPen); hydralazine (Apresoline); Insulin; nonsteroidal anti-inflammatory medications such as Motrin and Indocin; oral diabetes medications such as Glucotrol and Micronase;  (Minipress); quinidine (Quinaglute); ranitidine (Zantac); rifampin (Rifadin).

No known food/other substance interactions. 

Special Cautions

If pregnant or planning to become pregnant, inform your doctor immediately. Appears in breast milk; could affect a nursing infant.

No special precautions apply to seniors.

Not generally prescribed for children.

  • May cause drowsiness and impair your ability to drive a car or operate machinery. Do not take part in any activity that requires alertness.
  • Should not take Lopressor if you have: slow heartbeat, certain heart irregularities, low blood pressure, inadequate output from the heart, or heart failure.
  • Use with caution if you have: asthma, congestive heart failure, other bronchial conditions, or liver disease.
  • Ask your doctor if it is necessary to monitor your pulse during Lopressor therapy.
  • Inform your doctor if you are diabetic; Lopressor may mask low blood sugar symptoms.
  • Contact your doctor if you have difficulty breathing.
  • Inform your doctor or dentist that you are on Lopressor therapy during a medical emergency, or before you have surgery or dental treatment.


HealthSurvey.org provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Lopressor side effects, please contact your healthcare provider.