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S2 Inhalant

Generic name: racepinephrine

Brand names: Asthmanefrin, S2 Inhalant

Used for wheezing
Last updated November 3, 2026 0 views
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What is S2 Inhalant?

S2 Inhalant is a bronchodilator. It helps by relaxing the muscles in the airways to make breathing easier.

S2 Inhalant is used to relieve occasional asthma symptoms, including wheezing, chest tightness, and feeling short of breath.

S2 Inhalant may also be used for reasons not mentioned in this medication guide.

This section was rewritten for readability and reviewed for meaning.

Warnings

Do not use S2 Inhalant if you have taken an MAO inhibitor in the last 14 days, including isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.

This section was rewritten for readability and reviewed for meaning.

Before taking this medicine

Do not use S2 Inhalant unless a doctor has confirmed that you have asthma.

You should not use S2 Inhalant if you are allergic to it.

Do not use S2 Inhalant if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could happen. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.

Ask a doctor or pharmacist if it is safe for you to use this medicine if you have other medical conditions, especially:

  • heart disease;
  • high blood pressure;
  • diabetes;
  • a thyroid disorder;
  • mental illness or an emotional disorder;
  • seizures or epilepsy;
  • narrow-angle glaucoma; or
  • an enlarged prostate and urination problems.

It is not known if S2 Inhalant will harm an unborn baby. Do not use this medicine without a doctor's advice if you are pregnant.

It is not known if racepinephrine passes into breast milk or if it could harm a nursing baby. Do not use this medicine without a doctor's advice if you are breast-feeding a baby.

Do not give this medicine to a child younger than 4 years old without medical advice.

This section was rewritten for readability and reviewed for meaning.

S2 Inhalant side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

S2 Inhalant may cause serious side effects. Call your doctor right away if you experience:

  • new or worsening asthma symptoms;
  • fast heart rate, tremors, or a nervous feeling;
  • sleep problems (insomnia);
  • a seizure (convulsions); or
  • dangerously high blood pressure—severe headache, blurred vision, pounding in your neck or ears, nosebleed, anxiety, confusion, severe chest pain, shortness of breath, irregular heartbeats.

This is not a complete list of side effects and others may happen. Call your doctor for medical advice about side effects. You can report side effects to FDA at 1-800-FDA-1088.

This section was rewritten for readability and reviewed for meaning.

How should I use S2 Inhalant?

Use exactly as directed on the label, or as prescribed by your doctor. Do not take more than the recommended dose. Using too much S2 Inhalant or using it too often can increase your risk of heart attack or stroke, which can cause death.

S2 Inhalant is a liquid solution that must be placed into a hand-held bulb nebulizer. You will inhale the medicine from the nebulizer.

Any child using S2 Inhalant should be supervised by an adult while using this medicine.

After using S2 Inhalant, your symptoms should improve within 20 minutes.

Call your doctor right away if your symptoms do not improve within 20 minutes, or if they get worse after using S2 Inhalant.

Asthma is usually treated with a combination of drugs. Use all medications as directed by your doctor. Read the medication guide or patient instructions provided with each medication. Do not change your doses or medication schedule without your doctor's advice.

Seek medical attention if you think your medications are not working as well.

Signs that your asthma symptoms may be getting worse include:

  • having to use more than 12 inhalations of S2 Inhalant in a 24-hour period;
  • having to use more than 9 inhalations in 24 hours for 3 or more days in 1 week; or
  • having more than 2 asthma attacks in 1 week.

Store at room temperature away from moisture, heat, and light. Do not freeze.

Do not use S2 Inhalant if it looks brown or cloudy. Throw it out and get a new supply of racepinephrine.

What happens if I miss a dose?

Since S2 Inhalant is used as needed, you might not have a set dosing schedule. If you do have a schedule and miss a dose, take it as soon as you remember. If it’s almost time for your next scheduled dose, skip the missed dose. Do not use extra medicine to cover the missed dose.

Do not use more than 12 inhalations of racepinephrine in a 24-hour period.

This section was rewritten for readability and reviewed for meaning.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Avoid getting S2 Inhalant in your eyes.

Avoid eating or drinking products that contain caffeine, such as coffee, tea, soft drinks, or energy drinks. Taking caffeine while you are using S2 Inhalant can increase your blood pressure.

This section was rewritten for readability and reviewed for meaning.

What other drugs will affect S2 Inhalant?

Tell your doctor about all the medicines you are currently taking and any that you start or stop using, especially:

  • other asthma medications;
  • diet pills, appetite suppressants, or stimulant medicines;
  • cold or allergy medicines that contain a decongestant; or
  • antidepressants or medicines to treat mental illness.

This list is not complete. Other drugs may interact with racepinephrine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

This section was rewritten for readability and reviewed for meaning.

Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
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Content is provided for education and is not medical advice. See our medical disclaimer.