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Spilled Rx pill bottle: Sotalol side effects and how to avoid them
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Sotalol side effects and how to avoid them

Sotalol side effects include QT prolongation and hair loss
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By | Oct. 25, 2022 Medically reviewed by Marissa Walsh, Pharm.D., BCPS-AQ ID

Key takeaways

  • Sotalol, a beta blocker used to treat irregular heart rhythms, has common side effects including fatigue and dizziness, and serious side effects like QT prolongation and heart failure.

  • QT prolongation, a potentially serious heart problem indicated by a long QT interval on an ECG, is a significant side effect of sotalol, especially when combined with certain drugs or in individuals with electrolyte imbalances.

  • Less than 1% of people taking sotalol may experience hair loss, a side effect that is usually reversible upon discontinuation of the medication.

  • To avoid or manage sotalol side effects, it is crucial to inform the prescriber about all medical conditions and medications, adhere to prescribed dosages, and attend all follow-up appointments for regular monitoring.

In this article:

Sotalol is a generic prescription drug used to treat irregular heart rhythms including atrial fibrillation (AFIb) and life-threatening ventricular arrhythmias. Also sold as brand-name Sorine or Betapace, sotalol is a beta blocker that slows down the beating of the heart. Sotalol is usually taken at home as a tablet. However, the first doses may be given as an intravenous injection in a clinic or hospital. Side effects are commonly experienced. However, healthcare professionals are most concerned about its possible adverse effects on the heart.

Common side effects of sotalol

In clinical trials, the most common side effects of sotalol tablets were fatigue and dizziness. In order of likelihood, the most common side effects of sotalol are:

  • Fatigue
  • Dizziness
  • Slow heart rate
  • Shortness of breath
  • Nausea and vomiting
  • Excessive sweating
  • Diarrhea
  • Headache
  • Stomach pain
  • Palpitations

Serious side effects of sotalol

The most serious side effects of sotalol are:

  • Slow heart rate
  • Chest pain
  • Prolonged QT interval
  • Heart rhythm abnormalities
  • Heart block
  • Heart failure
  • Airway closure (bronchospasm)
  • Severe allergic reaction (anaphylaxis)

Sotalol and QT prolongation

The QT interval is a technical term for one part of a heartbeat. On an electrocardiogram or ECG, the QT interval is the part that has most of the up and down squiggles. What those ups and downs represent is the firing of nerves in the two lower chambers of the heart and then recharging – or contracting then relaxing. A long QT interval is considered a serious heart problem. It can create several problems: it can throw off the rhythm of the heartbeat (called an arrhythmia), slow down the heart, speed up the heart (ventricular tachycardia), cause lightheadedness or fainting, bring on seizures, and, in the worst-case scenario, sudden death. So, although QT prolongation may not sound like anything, a long QT interval is a serious side effect of sotalol and other beta blockers. 

Combining sotalol with certain other drugs may increase the risk. Some of the most important are listed below. Additionally, some people may be at higher risk for QT prolongation: women, people older than 65, people, people with adrenal gland cancer, sickle cell anemia, thyroid problems, sleep deprivation, or with autoimmune conditions such as lupus. The major risks for people taking sotalol, however, are electrolyte imbalances, especially low potassium or low magnesium. Any number of medical conditions, drugs, and behaviors can throw off the electrolyte balance in the body. Because of the risk, it’s very important for people taking sotalol to keep appointments with their healthcare providers. Regular blood tests can measure electrolytes and regular ECGs can spot heartbeat irregularities before they develop into a serious health threat.

Sotalol and hair loss

Beta blockers like sotalol can cause hair thinning. Healthcare providers believe that they poison hair follicles. It’s a rare side effect, though, occurring in less than 1% of people taking sotalol. In most cases, the hair loss can be reversed if the drug is stopped. It will typically take several weeks or months of treatment to notice that hair is thinning. If it happens, get medical advice from the prescribing healthcare provider. 

How soon do sotalol side effects start?

Changes in heart rate and rhythm including slow heartbeats can start right away after the first dose. Other minor side effects can happen early in treatment including dizziness, nausea, fatigue, and abdominal pain. Many of the serious side effects involving the heart can also start early in treatment.

How long do sotalol side effects last?

Some of the mild side effects of sotalol get better over time. However, most side effects should be reported to the prescriber. Some of them, such as vomiting, diarrhea, and sweating, may alter electrolyte levels in the body. This could lead to serious heart rhythm abnormalities. Others, such as dizziness and palpitations, could be a sign of a serious medical condition, not just a side effect. If side effects are too difficult to bear, they are usually reversible when the drug is discontinued. However, it takes about one or two weeks of a tapering dose to go off sotalol. 

What are the long-term side effects of sotalol?

Sotalol can be taken for a long time, but it does have a high risk for adverse effects involving the heart. These effects will always be a risk throughout treatment. However, there are no side effects specifically due to long-term use.

Sotalol contraindications

Because of the possibility of serious side effects, sotalol is never prescribed to people with:

  • A slow heart rate with a normal heart rhythm (sinus bradycardia)
  • Second- or third-degree heart block (except in people with a pacemaker)
  • Sick sinus syndrome (a defect in the heart’s natural pacemaker) except in people with a pacemaker
  • Cardiogenic shock (a medical condition in which the heart does not pump enough blood to the body)
  • Decompensated heart failure
  • Prolonged QT syndromes
  • Uncorrected low potassium
  • Bronchial asthma
  • Chronic obstructive pulmonary disease (COPD)
  • Severe kidney dysfunction (in people with atrial fibrillation)
  • Allergic to the drug

Pregnancy

Sotalol is not recommended during pregnancy unless absolutely necessary because it can cause serious side effects in both the mother and the fetus.

Breastfeeding

Sotalol is not recommended when breastfeeding. Sotalol is present in human breast milk in high concentrations and could cause serious side effects in a nursing infant. Healthcare professionals are advised to tell women to stop breastfeeding when taking sotalol.

Children

Sotalol is FDA approved for use in children as young as newborns to treat atrial fibrillation and ventricular arrhythmias. Side effects are about the same for infants and children as they are for adults.

Seniors

Sotalol is approved for use in seniors, but there’s a slightly higher risk of heart rhythm abnormalities. Additionally, elderly adults who take heart rhythm drugs (antiarrhythmics) in general are at increased risk to experience adverse effects in comparison to younger adults. Healthcare professionals are advised to monitor for side effects more closely in the elderly.

Sotalol warnings

All prescription drugs that change the way the heart beats are used with caution in some people because of pre-existing conditions. Additionally, an overdose or stopping the medicine abruptly could have serious consequences.

Black box warning

Black box warnings are mandated by the FDA if it considers that a drug has certain high-risk hazards. Sotalol comes with three warnings in its drug information:

  • The first warning is for healthcare providers to initiate and titrate sotalol doses in facilities that can provide continuous ECG monitoring.
  • The second warning reminds healthcare providers and pharmacists not to substitute sotalol tablets for sotalol AF tablets.
  • The third warning touches on the possibility of the lower chambers of the heart beating too fast (ventricular tachycardia) so not to initiate therapy in people with a long QT interval and to modify the dose, dosing interval, or discontinue therapy in those who experience an excessive prolongation of their baseline QT.

Cautions

Sotalol slows down the heart, so the main worry is what may happen to people who already have existing heart conditions or blood vessel problems. These include:

  • Slow heart rate
  • Heart failure
  • A recent heart attack
  • A history of a fast heartbeat called torsade de pointes
  • A family history of QT prolongation
  • Coronary artery disease
  • Low blood pressure

Sotalol can cause problems with other pre-existing medical conditions, including:

  • Kidney impairment. People with reduced kidney function do not eliminate sotalol from the body as well as others, raising the risk of side effects. Dose adjustments are required, and alternate therapy is recommended for those with very reduced kidney function.
  • Diabetes. Beta blockers like sotalol can worsen low blood sugar (hypoglycemia) in people taking diabetes medications.
  • Thyroid disorders. Sotalol can mask the symptoms of an overactive thyroid, making diagnosis and treatment more difficult.
  • Raynaud’s phenomenon. Sotalol can worsen Raynaud’s phenomenon and other diseases of the peripheral blood vessels (peripheral vascular disease or PVD).
  • Adrenal gland cancer. People with pheochromocytoma, a type of adrenal gland cancer, are more at risk for heart rhythm irregularities when taking sotalol.
  • Surgery. Sotalol and other beta blockers increase the risks associated with surgery and general anesthesia.

Abuse and dependence

Sotalol is not associated with physical dependence or drug abuse. 

Withdrawal

Although the body does not become physically dependent on sotalol, the abrupt discontinuation of sotalol can bring about serious problems such as chest pain or heart attack. It can also bring about serious and potentially life-threatening thyroid problems in people with an overactive thyroid. When it is time to stop sotalol, the healthcare provider will prescribe a steadily decreasing dose over a one- to two-week period. 

Overdose

Taking too much sotalol could be fatal, so get immediate emergency medical care if too much is taken either intentionally or by accident.

Sotalol interactions

Because sotalol affects the pace and rhythm of the heart, the most concerning drug interactions involve drugs that also change heartbeats or lower blood pressure. These include: 

Other drugs that could cause problems when combined with sotalol include:

  • Carbonic anhydrase inhibitors. A family of drugs used as diuretics, anticonvulsants, or to treat glaucoma, these drugs can cause electrolyte imbalances that could result in heart rhythm problems in people taking sotalol
  • Antacids. Antacids reduce the body’s absorption of sotalol, making it less effective. Do not take a sotalol dose within two hours of taking an antacid.

How to avoid sotalol side effects

Sotalol can cause some serious problems, so become familiar with the side effects and how to avoid them before taking this drug.

1. Tell the prescriber about all medical conditions

It is likely the prescriber will have a pretty complete picture of your medical history, but make sure the prescriber knows about:

  • Coronary artery disease
  • Heart failure
  • Electrolyte imbalances
  • Bronchial asthma
  • Emphysema or bronchitis
  • Diabetes
  • Thyroid problems
  • Any upcoming surgery
  • Pregnancy or any plans to become pregnant
  • Breastfeeding or plans to breastfeed

2. Tell the prescriber about any drugs being taken

To avoid side effects caused by drug interactions, tell the prescriber about all the prescription drugs, over-the-counter medicines, and dietary supplements that are regularly taken. Do not start taking any new drugs until consulting with the prescriber.

3. Keep all follow-up visits

It is very important not to miss follow-up visits. Regular ECGs are required. Blood tests will also need to be performed to check electrolytes. 

4. Follow the directions

Take this medicine as directed by the prescribing healthcare provider. Don’t miss doses. Don’t take extra medicine. Don’t take sotalol tablets more often than directed. 

5. Don’t take missed doses

If a dose of sotalol is missed, skip it. Take the next dose as scheduled.

6. Don’t stop taking sotalol

Don’t stop taking sotalol tablets except under the direction of a healthcare professional. The sudden discontinuation of sotalol can bring on serious and even life-threatening crises such as heart attack. 

7. Drink less alcohol

Drinking alcohol could worsen some of sotalol’s side effects including low blood pressure and dizziness.

How to treat side effects of sotalol

Side effects are likely when taking sotalol. In many cases, the prescribing healthcare provider will need to know about them.

Dizziness or lightheadedness

Sit down and rest. When the dizziness or sleepiness has passed, then contact the prescribing healthcare provider.

Vomiting

Because of the risk for electrolyte imbalances, immediately report vomiting to the prescribing healthcare provider. Prolonged or severe diarrhea will require medical treatment.

Diarrhea

Drink fluids to prevent dehydration. Again, there’s a risk of electrolytes being thrown out of balance. Immediately report problems with severe or prolonged diarrhea to the prescribing healthcare provider.

Excessive sweating

Like diarrhea and vomiting, excessive sweating raises the risk of electrolyte abnormalities. Report this side effect to the prescribing healthcare provider.

Dehydration

Drink fluids when feeling thirsty to avoid dehydration. Because electrolyte imbalance is a serious threat when taking sotalol, tell the healthcare provider if thirst becomes excessive.

Feeling faint 

Immediately contact the prescribing healthcare provider if fainting or feeling faint is experienced.

Palpitations or other heart problems

Contact the prescriber immediately if experiencing a fast heartbeat, palpitations, slow heartbeats, or chest pain.

Heart failure

Heart failure is possible when taking sotalol. If that happens, the heart cannot pump enough blood to the body. Immediate medical care is needed if symptoms of heart failure are noticed including swelling, rapid weight gain, and trouble breathing.

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