How Antibiotics for Bronchitis Work

By Terez Malka, MD
Medically reviewed checkmarkMedically reviewed
January 4, 2022

Bronchitis, commonly referred to as a chest cold, is tough on your respiratory system and causes persistent coughing.

Using antibiotics to treat bronchitis is controversial, though, since in almost all cases, they are not necessary and will not help.

That’s because 90% of bronchitis infections are caused by viruses, and antibiotics only work on bacterial infections, not viral ones.

Still, approximately two-thirds of patients in the United States diagnosed with bronchitis are treated with antibiotics.

Using antibiotics when they are not needed will not help your symptoms.

But it can cause unwanted side effects and lead to a rise in antibiotic-resistant bacteria.

In some cases, bronchitis can be caused by harmful bacteria.

That’s where antibiotics come in.

In this article, I’ll talk more about acute bronchitis, including its causes, symptoms, and how it’s diagnosed.

I’ll outline the antibiotics that your doctor or healthcare provider may prescribe for bronchitis, and list some of their side effects.

I’ll also detail some other treatments that can help, and tell you when you should talk to a doctor or other healthcare provider.

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What is a Chest Cold (Acute Bronchitis)?

Acute bronchitis is typically caused by a viral respiratory infection.

It occurs when the bronchi, the two main airways that carry oxygen to our lungs, become swollen and inflamed.

The inflammation leads to increased mucus production, which narrows the airways and makes breathing more difficult. 

Most cases of acute bronchitis get better within 7-10 days, though the accompanying cough often lasts for several weeks. 

Bronchitis Basics


Acute bronchitis is usually caused by the same viruses that cause colds and the flu.

When these viruses affect the lining of the bronchial tubes, bronchitis occurs.

Chronic bronchitis lasts much longer than acute bronchitis, and is usually caused by long-term exposure to air pollutants or cigarette smoke.

You are at a high risk of developing chronic bronchitis if you are a smoker, are regularly exposed to toxic air chemicals, including secondhand smoke, or if you have certain genetic conditions.


Common symptoms of bronchitis include: 

Diagnosis of Bronchitis

If your doctor or provider suspects you have bronchitis, they will perform a physical examination and evaluate your symptoms.

During the physical examination, they will likely use a stethoscope to listen to your breathing.

They will also want to know how long you have had a cough and whether you produce mucus when you cough.

In some circumstances, they may want to order a CT scan, chest X-ray, or pulmonary function tests, as well as lab work to rule out other conditions.

In most cases, bronchitis is diagnosed only by an exam and discussing your symptoms.

If you have a compromised immune system, or severe or chronic symptoms, a sample of sputum (a mixture of saliva and mucus) from a cough may also be examined for the presence of bacteria, viruses, or fungi.

This test is usually only performed in severely ill or hospitalized patients, or if you have certain chronic health conditions. 

Types of Antibiotics for Bronchitis 

Antibiotics are not recommended as a primary treatment for bronchitis because most cases are caused by viral infections.

Antibiotics are not effective against viruses.

However, if your doctor suspects a bacterial infection, you may be prescribed one of the following antibiotics:

  • Fluoroquinolones: These are typically prescribed to people suffering from a severe airway obstruction. Respiratory fluoroquinolones include moxifloxacin (Vigamox), levofloxacin (Levaquin), and gemifloxacin (Factive). These carry higher risks for side effects than some other antibiotics, so your provider will determine if these are the right choice for your infection.
  • Aminopenicillins: Sometimes referred to as third generation penicillins, aminopenicillins kill bacteria in the same way as the original, but are less susceptible to bacterial resistance. Amoxicillin and clavulanate potassium (Augmentin) is one penicillin that may be used to treat bacterial bronchitis. 
  • Cephalosporins: Second-generation cephalosporins in particular are effective in fighting gram-negative bacteria, and are often prescribed to treat bacterial respiratory infections like bronchitis. 

Macrolide antibiotics like azithromycin used to be prescribed for bronchitis. But with growing antibiotic resistance, these are no longer considered a good treatment option in most cases.

Side Effects of Antibiotics For Bronchitis

Aside from their lack of effectiveness against the usual viral causes of bronchitis, the risk of side effects is another reason antibiotics are not commonly used to treat bronchitis.

Common side effects of the antibiotics used to treat bronchitis include:

Alternative Treatments

Acute bronchitis will usually go away on its own after a few days or weeks.

There are, however, some treatment methods that can offer relief from symptoms while you recover.

  • Steam: Using steam from a vaporizer or a humidifier can help clear up your air passages.
  • Lozenges and honey: These can soothe a sore throat.
  • Over-the-counter (OTC) medicines: For pain and fever, over-the-counter medicines like ibuprofen (Advil) and acetaminophen (Tylenol) can offer relief. Decongestants like pseudoephedrine (Sudafed), and antihistamines like cetirizine (Zyrtec) or loratadine (Claritin) can also be helpful.
  • Expectorants: These OTC medications, like guaifenesin (Mucinex), can help thin mucus so it is easier to cough up.
  • Fluids: Stay hydrated and include some hot liquids to help clear out mucus.
  • Rest: Get plenty of rest as you wait for the illness to pass.
  • Prescription cough suppressants: If your symptoms are not getting better with OTC treatment and you do not require an antibiotic, your doctor may prescribe a cough suppressant or inhaler to help manage your cough.

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When to See a Doctor

Bronchitis can be similar to or associated with the common cold, COVID-19, or the flu, so it’s important to pay attention to your symptoms—especially if those symptoms include a cough or difficulty breathing.

See a doctor if you have any of the following symptoms:

  • Cold symptoms lasting more than three weeks 
  • Cold symptoms becoming extreme or severe 
  • A fever over 102° F (38.9°C) for more than three days
  • Coughing up or producing blood
  • Trouble breathing
  • An underlying health condition, such as asthma or COPD

If you are taking prescribed antibiotics and experience any of the side effects mentioned above, stop taking the medication and contact your doctor immediately. 

If you think you’re having an allergic reaction, call 9-1-1 or go to the emergency room. 

How K Health Can Help

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Frequently Asked Questions

What is the best antibiotic for bronchitis?
There is no best antibiotic for bronchitis, and in most cases, antibiotics are not needed at all. There are several different antibiotics that could be prescribed by a doctor depending on the type of bacteria causing the infection and your health history.
What antibiotic clears up bronchitis?
Most cases of bronchitis are viral, so antibiotics are not primarily recommended to treat the condition—antibiotics do not work against viruses. A doctor may recommend antibiotics if a bacterial infection is present or if you have certain chronic lung or immune system conditions. Antibiotics typically prescribed include doxycycline, fluoroquinolones, aminopenicillins, and cephalosporins.
Do antibiotics work for bronchitis?
When bronchitis is caused by a bacterial infection, antibiotics can help improve the condition. Antibiotics are not effective when bronchitis is caused by a viral infection. Ninety percent of bronchitis cases are due to a virus, and do not require antibiotics.
What is the fastest way to cure bronchitis?
The quickest way to get over acute bronchitis is with time and rest. Your immune system will usually take 7-10 days to clear up the infection. If your acute bronchitis was caused by a bacterial infection, your doctor will prescribe antibiotics. For chronic bronchitis, talk to a healthcare professional about recommended methods of treatment.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Terez Malka, MD

Dr. Terez Malka is a board-certified pediatrician and emergency medicine physician.