Taking Doxycycline for a Sinus Infection? Here's What to Expect

Medically reviewed by Femi Aremu, PharmD

Doxycycline is an antibiotic in the tetracycline family used to treat acute bacterial sinus infections in people allergic to penicillin. It is also commonly used to treat acne, skin infections like cellulitis, and some sexually transmitted infections (STIs).

Doxycycline is sometimes prescribed as an alternative to amoxicillin, another antibiotic used for sinus infections, in people allergic to penicillin-type antibiotics.

This article will discuss doxycycline’s role as an antibiotic in treating sinus infections, how it works, and what to expect when taking doxycycline for a sinus infection.

How Does Doxycycline Work for a Sinus Infection?

Doxycycline blocks bacteria from producing proteins needed to replicate, thereby preventing bacteria from multiplying further. Doxycycline does not kill bacteria; it is considered bacteriostatic, meaning that it suppresses the growth of bacteria.

Doxycycline and other antibiotics only work for bacterial sinus infections, though. They will not treat viral infections.

How to Take Doxycycline for a Sinus Infection

Doxycycline for sinusitis is usually prescribed as 100 milligrams (mg) twice daily for five to seven days. Alternatively, it can be taken at 200 milligrams once a day.

Some formulations of doxycycline are best taken on an empty stomach, while others can be taken with or without food. Ask your pharmacist about the specific formulation you are receiving at the pharmacy. If taking doxycycline irritates your stomach, you can try taking it with food or milk to prevent this.

Be sure to swallow the capsule or tablet with a large amount of water to ensure that it does not remain in the esophagus, where it could cause irritation.

How Long Will Doxycycline Take to Work?

Symptoms of acute sinusitis should begin to improve three to five days after starting doxycycline.

To clear the infection, take doxycycline for the entire prescribed duration, usually five to seven days. It's important to continue to take your medication even if you begin to feel better. Stopping your antibiotic regimen early can contribute to antibiotic resistance, and your infection could return.

What Side Effects Should I Expect?

Like other antibiotics, doxycycline can sometimes cause side effects. However, it is generally considered well tolerated among most people.

Side effects of doxycycline may include:

• Photosensitivity: Doxycycline can make your skin more sensitive to the sun. Avoid prolonged sun exposure, and wear sunscreen and protective clothing to cover your skin in the sun while taking this antibiotic.

• Diarrhea: Diarrhea is a common side effect of antibiotics that usually clears once antibiotics are finished. Call your healthcare provider if the diarrhea is severe, does not stop, or is bloody.

• Other gastrointestinal-related issues, like stomach upset and nausea/vomiting

Serious side effects of doxycycline may include:

• Severe allergic skin reaction: Doxycycline can sometimes cause skin reactions that can progress to severe and life-threatening. If you notice a sudden allergic skin reaction, stop taking doxycycline and seek care from a healthcare provider immediately.

• C. diff diarrhea: C. difficile diarrhea can occur up to two months after taking antibiotics. See a healthcare provider for evaluation if you experience large amounts of watery diarrhea or bloody diarrhea.

• Intracranial hypertension (pseudotumor cerebri): Doxycycline has been associated with an increase in intracranial pressure. Symptoms include headache, blurred vision, double vision, or vision loss. If visual disturbance occurs while taking doxycycline, seek a prompt eye evaluation.

Precautions

Doxycycline should not be taken during pregnancy, as it can harm a fetus.

Because doxycycline can cause permanent tooth discoloration in developing teeth, it should not be used in children 8 years and younger unless the benefits outweigh the risk (e.g., treatment of anthrax, Rocky Mountain spotted fever).

Alternative Treatments for a Sinus Infection

The usual first-line antibiotic chosen for treating a bacterial sinus infection in people who are not allergic to penicillin is Amoxil (amoxicillin) or Augmentin (amoxicillin-clavulanate).

The other antibiotic option besides doxycycline for people allergic to penicillin is a respiratory fluoroquinolone such as levofloxacin or Avelox (moxifloxacin).

Over-the-counter (OTC) products can help with symptomatic relief. These can include:

• Nasal decongestant sprays

• Oral decongestants, such as Sudafed (pseudoephedrine)

• Nasal saline irrigation

• OTC pain relief medications like Advil (ibuprofen) or Tylenol (acetaminophen)

• Antihistamines, such as Benadryl (diphenhydramine)
  

Related: Is Augmentin Better Than Amoxicillin?

Summary

Doxycycline is a tetracycline antibiotic prescribed for acute bacterial sinusitis. It is usually the treatment of choice for people who cannot take penicillin. It’s typically prescribed for five to seven days and is tolerated with minimal side effects by most people.

You should start to feel better within three to five days of starting doxycycline; if you don’t feel better or your symptoms worsen, this could mean a virus or a resistant bacteria cause your sinus infection. You should return to a healthcare provider for reevaluation.

Frequently Asked Questions

Is doxycycline more effective than amoxicillin for a sinus infection?

Doxycycline is similarly effective to amoxicillin for treating a sinus infection. Amoxicillin is usually chosen in people who do not have an allergy to penicillin, while doxycycline is used in people with a history of penicillin allergy.

What if my symptoms don’t resolve after I take doxycycline?

If you have no improvement in symptoms after taking doxycycline for three to five days, contact your healthcare provider. Potential causes for non-response include sinusitis caused by a virus or resistant bacteria. You might need a different treatment.