How to Safely Stop Taking Metoprolol

Metoprolol is a prescription-based, orally administered (taken by mouth) beta-blocker used to treat various cardiovascular (heart)-related conditions. Beta-blockers reduce the heart rate, lower the heart's oxygen demand, and reduce the frequency of angina attacks.

Specifically, it is used alone or with other medicines to improve blood flow and decrease hypertension (high blood pressure). It also treats chronic (long-term) angina (chest pain) and heart stress following a heart attack. 

Metoprolol is often a first-line drug of choice for people with heart conditions. However, starting and stopping the use of metoprolol should be done carefully and as prescribed.

This article will explain the steps and precautions needed to safely wean off metoprolol and other relevant information about the safe use of this commonly prescribed medication.

How Does Metoprolol Work?

Beta-blockers, like metoprolol, are also referred to as beta-adrenergic blocking agents.

Specifically, metoprolol works by blocking the release of the stress hormones adrenaline and noradrenaline from acting on beta receptors in blood vessels and the heart.

This inhibitory effect causes the blood vessels to relax. The relaxation of blood vessels slows the heart rate and reduces the heart’s need for oxygen. This, in turn, helps to lower blood pressure and relieve chest pain.

Metoprolol is available in generic and brand-name form, including Lopressor (metoprolol tartrate), an immediate-release (IR; a formulation designed to be swallowed whole where the drug instantaneously disintegrates) tablet, and Toprol-XL (metoprolol succinate), an extended-release (ER; a formulation intended to dissolve slower in the body, therefore meant to last longer and require fewer dosages) capsule.

Metoprolol is also combined with a diuretic (water pill) hydrochlorothiazide. The combination is available under Lopressor HCT to treat high blood pressure.

Metoprolol is also used to improve survival after a heart attack and in combination with other drugs to treat heart failure. Metoprolol relaxes blood vessels by acting on specific receptors to enhance blood flow and decrease blood pressure.

How to Stop Taking Metoprolol

All brands and generic version of metoprolol comes with a boxed warning on how to stop taking metoprolol. So, you'll need to follow the precise instructions laid out by your healthcare provider.

Most significantly, the sudden discontinuation of metoprolol may lead to withdrawal syndrome (with the potential for accompanying tachycardia [increased heart rate] and hypertension), worsening chest pain, irregular heartbeat, and an increased risk of a heart attack.

As you complete your prescription, the FDA warns you to slowly taper (reduce) the dose over one week or two before stopping it altogether. Your healthcare provider will gradually decrease the quantity under close supervision to avoid severe adverse effects.

Also, your healthcare provider will determine the metoprolol dose considering age, body weight, and health condition.

You must ensure not to discontinue metoprolol on your own even if your symptoms are improving or you are feeling well. It can be highly life-threatening.

Who Should Use Metoprolol?

Beta-blockers like metoprolol are widely prescribed for people with heart disease in combination with other drugs to treat people with the following conditions:

• Treatment of angina: By reducing the heart rate, beta blockers are used as first-line treatment in people with angina, either alone or in combination with a calcium channel blocker.
• Treatment of heart failure: Beta-blockers improve life expectancy in people with heart failure caused by impaired contraction of the left ventricle (the main pump chamber of the heart). Beta-blocker works with angiotensin-converting enzyme (ACE) inhibitors, for example, Altace (ramipril), and in many cases, an aldosterone inhibitor.
• Treatment of some heart rhythm disorders: Beta-blockers control irregular heart rhythm in people with atrial fibrillation (AF). These drug symptoms caused by AF, particularly palpitations and fatigue, are often improved by slowing the heart rate.
• Protection against recurrent heart attacks: In people who have had a heart attack, beta-blockers help reduce the risk of heart attacks in the future. 
• Control of blood pressure: Beta-blockers are commonly used to help lower blood pressure in combination with other medicines, such as an ACE inhibitor, or a calcium channel blocker.

For context, hypertension is caused by an increased pressure in your blood vessels than usual.

Hypertension causes the heart to pump blood harder. An average blood pressure level is less than 120/80 millimeters of mercury (mmHg). If hypertension is not controlled and treated, it can be life-threatening.

In comparison, angina pectoris causes pain, pressure, squeezing, or discomfort in the center of the chest or neck, jaw, shoulder, back, or arm. It is caused when the heart muscle doesn't get enough oxygen-rich blood as it needs.

Angina is not a disease but a symptom of an underlying cardiac problem such as ischemic heart disease. A major cause of angina is the blockage or narrowing of one or more of the heart's arteries, also called ischemia (low oxygen supply due to decreased blood flow).

Who Shouldn't Take Metoprolol?

Various formulations of metoprolol (such as Lopressor HCT, Toprol XL, or Lopressor) are discouraged in people with the following preexisting conditions:

• People who are hypersensitive to any active ingredient of metoprolol
• Cardiac failure
• Cardiogenic shock
• Sinus bradycardia
• Decompensated heart failure (DHF)
• Heart block greater than first-degree, such as second- or third-degree heart block
• Pheochromocytoma (tumor-causing unregulated and excessive amounts of adrenaline). 
• Severe peripheral arterial circulatory disorders
• Sick sinus syndrome (unless a permanent pacemaker has been inserted)
• Have experienced a recent dental surgery

Furthermore, be sure to discuss with your healthcare provider before taking metoprolol if you have any of the following conditions:

• Asthma or other lung diseases
• Hyperthyroidism (an overactive thyroid gland)

Pregnant people or those planning to become pregnant should consult with their healthcare provider before starting metoprolol, including those currently breastfeeding.

Side Effects & Safety

Metoprolol carries a boxed warning as designated by the Food and Drug Administration (FDA); the sudden discontinuation of metoprolol may lead to withdrawal effects causing severe chest pain, a heart attack, or cardiac arrhythmia (irregular heartbeat).

Like all drugs, metoprolol carries the potential for adverse effects.

Therefore, discuss with your healthcare provider what side effects you may be personally susceptible to before starting treatment and what can be done to strengthen the odds of healthily and effectively completing the entire duration of your prescription.

Common Side Effects

Some common side effects of metoprolol include:

• Cold hands and feet
• Constipation
• Depression
• Diarrhea
• Dizziness
• Dry mouth
• Gas or bloating
• Heartburn
• Itching
• Nausea
• Runny nose
• Stomach pain
• Tiredness
• Vomiting

If any of these side effects appear and continue to worsen, reach out to your healthcare provider immediately.

Severe Side Effects

Metoprolol may cause some severe side effects. Immediately call your healthcare provider if you experience any of the following symptoms:

• Fainting
• Irregular heartbeat
• Shortness of breath or difficulty breathing
• Swelling of the hands, feet, ankles, or lower legs
• Weight gain
• Wheezing

Abrupt discontinuation of the metoprolol may lead to a withdrawal syndrome that could cause angina or myocardial infarction.

As explained earlier, tachycardia and hypertension are common in withdrawal syndrome. To avoid this, a healthcare provider will slowly reduce the dosage before stopping the drug to prevent withdrawal symptoms.

What Drugs Interact With Metoprolol?

Metoprolol interacts with certain drugs when used together. Call your healthcare provider before taking these drugs alongside metoprolol:

Catecholamine (hormones produced by the adrenal glands)-depleting drugs:

These drugs may cause an additive effect with metoprolol and can cause low blood pressure (hypotension), bradycardia (a slowed heartbeat), vertigo, sudden fainting (vasovagal syncope), or postural hypotension (sudden drop in blood pressure when standing from a sitting position).

Such examples include:

• Monoamine oxidase (MAO) inhibitors (class of antidepressants), such as Marplan (isocarboxazid), Nardil (phenelzine), Emsam (selegiline), and Parnate (tranylcypromine).
  

Potent inhibitors of CYP2D6:

Inhibitors of CYP2D6 (an enzyme found in the liver that plays a role in the effectiveness of certain drugs, such as antidepressants or neuroleptics) may hinder metoprolol's ability to work effectively. Closely monitor when taking these drugs together. 

Such examples include:

• Prozac (fluoxetine)
• Paxil CR (paroxetine)
• Rythmol SR (propafenone)
  

Always tell your healthcare provider about all your drugs before starting metoprolol. Your healthcare provider may alter the dose of these medicines to avoid any interactions. 

Summary

Metoprolol is widely prescribed to manage and treat various cardiovascular disorders.

It is available in multiple brand and generic names in different dosage forms. Metoprolol is used alone and in combination with other cardiovascular drugs. 

Metoprolol is generally safe and effective but must only be used as prescribed. The most critical warning regarding using metoprolol is how to stop taking it.

All brands and generic version of metoprolol comes with a boxed warning about the sudden discontinuation of the drug.

Premature discontinuation may lead to a withdrawal syndrome that can worsen chest pain and arrhythmias, hypertension, and increase the risk of a heart attack. 

It is necessary to slowly reduce the dose over some time and then stop the drug. Your healthcare provider will taper the dose and monitor you for side effects.

In many treatment plans, you may need to take metoprolol for a long time or even for the rest of your life.