Beta-Agonist Toxicity (Albuterol Overdose)

What to do right now

1. If someone is having trouble breathing, treat the asthma or COPD first: keep using the rescue inhaler as directed by their asthma action plan and call 911 if they are not improving. Do not withhold treatment for fear of overdose.
2. For an accidental swallow or overdose, call Poison Control at 1-800-222-1222 (US), or 911 if the person has chest pain, fainting, confusion or a seizure.
3. Have the medicine package ready, with the name, strength, how much was taken and when.
4. Keep the person resting and do not give other stimulants such as caffeine or energy drinks.

How beta-agonists work and why too much causes problems

Beta-2 agonists relax the airway muscles by stimulating beta-2 receptors. At higher doses they also stimulate:

• Heart receptors: faster heart rate and palpitations, and at high levels abnormal rhythms.
• Skeletal muscle receptors: tremor and shakiness.
• Metabolic effects: potassium shifts into cells, causing low potassium in the blood; blood sugar and lactate rise.
• Blood vessels: widening, which can lower diastolic blood pressure and cause flushing.

Common causes

• Overusing a rescue inhaler during a worsening asthma or COPD flare. Frequent nebulizer treatments in the ER also cause predictable side effects.
• Children swallowing albuterol tablets or syrup, or drinking nebulizer solution.
• Combining long-acting and short-acting beta-agonists at higher than prescribed doses.
• Misuse: clenbuterol, a veterinary beta-agonist sometimes misused for weight loss or bodybuilding, causes severe toxicity and is not approved for human use in the US.
• Terbutaline given to delay preterm labor, which can affect the mother and baby.

Symptoms

Common

• fast heart rate and palpitations
• tremor, especially of the hands
• nervousness, restlessness, agitation
• headache, flushing
• nausea and vomiting
• muscle cramps

Serious

• chest pain or signs of heart strain, particularly in people with heart disease
• arrhythmias such as atrial fibrillation or supraventricular tachycardia
• very low potassium causing weakness or rhythm problems
• high blood sugar and lactic acidosis, which can cause fast breathing
• seizures, rarely, after very large ingestions

Diagnosis

Diagnosis is based on the history of exposure and symptoms. In the ER, doctors check:

• heart rate, blood pressure, and an ECG for rhythm problems and heart strain
• blood potassium, glucose, lactate and magnesium
• troponin if there is chest pain

Fast breathing from lactic acidosis can be mistaken for worsening asthma, so blood tests help guide treatment.

Treatment

Most cases need only observation until symptoms settle, usually within 4 to 6 hours for inhaled albuterol, longer for tablets and long-acting medicines.

• Supportive care: rest, IV fluids and heart monitoring.
• Potassium: replaced only cautiously, because levels usually return to normal as the medicine wears off and over-replacement can cause high potassium later.
• Sedation: benzodiazepines for agitation or tremor.
• Beta-blockers: sometimes used for severe tachycardia, but with great caution in people with asthma because they can trigger bronchospasm.
• Activated charcoal: may be considered soon after a large tablet ingestion.

Outlook

Most people recover fully within hours. Serious complications are uncommon and mainly occur with large ingestions or underlying heart disease.

Prevention

• Follow your asthma action plan and know how many puffs to take and how often.
• If you need your rescue inhaler more than twice a week, or more often than usual, see your doctor. Better preventer treatment reduces rescue use.
• Store all medicines, including inhalers and syrups, out of children's reach in child-resistant containers.
• Do not use clenbuterol or other beta-agonists for weight loss or bodybuilding.

Frequently asked questions

What happens if you use too much albuterol?

Common effects are a fast heartbeat, shakiness, nervousness, headache, nausea and muscle cramps. Blood potassium can drop and blood sugar can rise. Large overdoses can cause chest pain or abnormal heart rhythms. Most symptoms settle within a few hours.

Can you overdose on an albuterol inhaler?

It is uncommon to take a dangerous overdose from an inhaler alone, but heavy use can cause significant side effects. Needing many extra puffs usually means asthma is out of control, which is itself dangerous. Seek urgent care if breathing is not improving.

How long do albuterol side effects last?

Shakiness and a fast heartbeat from inhaled albuterol usually peak within 30 to 60 minutes and fade within 3 to 6 hours. Effects from tablets, syrups or long-acting medicines last longer.

What should I do if my child swallowed albuterol syrup or tablets?

Call Poison Control at 1-800-222-1222 (US) straight away, even if your child seems fine. Have the bottle ready. Call 911 if your child has chest pain, fainting, a seizure, extreme agitation or a very fast heartbeat.