Does Bactrim work for sinus infections?

Sinus infections are a common illness—affecting about 29 million people a year—that no one wants to experience. The symptoms make you downright miserable, but can taking a prescription help? It depends. Bactrim is an antibiotic prescribed for a number of infections. Keep reading to learn the pros and cons of Bactrim for sinus infections. 

What is a sinus infection?

A sinus infection, also known as sinusitis or rhinosinusitis, is inflammation of the inside of the nose and sinuses. Viruses cause most sinus infections—and they are often contagious, as the viruses are easily spread. But, about 2% are caused by bacteria. On rare occasions, sinus infections can be caused by a fungus.

Common symptoms of sinus infections include:

• Nasal congestion
• Facial pain or pressure across the upper cheeks or forehead
• Sore throat
• Headache
• Yellow or greenish nasal drainage

Sinus infections can be acute (short), lasting up to four weeks, or subacute, lasting from 4 to 12 weeks. Chronic sinusitis lasts longer than 12 weeks. Not all sinus infections require antibiotics. Only those caused by bacterial infections will improve when treated with medication. Viral sinus infections clear up with only supportive treatment.

Is Bactrim good for sinus infections?

Bactrim (sulfamethoxazole–trimethoprim) is not the first-line treatment for acute sinusitis, where antibiotics are indicated. 

“The first choice for sinus infections is amoxicillin or amoxicillin with clavulanate (Augmentin),” says Mary Sheehan, RPh, a pharmacist in Akron, Ohio. 

However, in the past, Bactrim was a treatment choice for patients who had ongoing symptoms or were allergic to penicillins, cephalosporins, and related medications. This medication was also a choice for patients who recently took a different antibiotic that didn’t work and were in need of another treatment. In recent years, higher rates of bacterial resistance to Bactrim have made it less useful for sinusitis, and currently, it is not recommended in most cases.

Bactrim is used to treat several types of bacterial infections, predominantly urinary tract infections and infections related to methicillin-resistant staph aureus (MRSA). This medication combines two antibiotics that work together to rid the body of the bacteria causing the infection.

“Bactrim can be used to treat bacterial sinus infections caused by Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis,” says David Seitz, MD, a board-certified physician practicing in New York. “Bactrim can also help treat infections caused by other bacterial strains, depending on the severity and type of infection.” The concern is that Streptococcus pneumoniae is a major cause of bacterial sinusitis, and this bacteria has a significant likelihood of being resistant to Bactrim. 

Bactrim is no longer a common choice for persistent sinusitis. If symptoms are severe or do not improve with initial antibiotics, stronger antibiotics are available, such as Levaquin and doxycycline.

How much Bactrim should I take for a sinus infection?

Your healthcare provider will prescribe the appropriate dose of Bactrim to treat your individual symptoms. Bactrim comes in two strengths:

• Bactrim 400-80 milligrams

• Bactrim DS 800-160 milligrams

In this case, DS means “double strength.” The dose may be adjusted based on the patient’s age, weight, kidney function, or illness. Depending on these factors, your provider could prescribe anywhere from one to two tablets of Bactrim DS 800-160 milligrams or Bactrim 400-80 milligrams every 12 to 24 hours. The dose for children is based on weight and often comes in a liquid form. Bactrim should never be given to infants younger than 2 months old.

The dose of antibiotic and length of treatment depend on the illness or the bacteria likely causing the illness. More aggressive infections require longer treatments and higher-strength antibiotics than other infections.

Like most antibiotics, it may take three to four days for people to notice improvement after starting Bactrim. Be sure to take the medication as directed. You should finish taking the full course of antibiotics, even after you start to feel better. 

Bactrim side effects

As with any medication, there are potential side effects. Common side effects of Bactrim include:

• Nausea
• Vomiting
• Diarrhea
• Decreased appetite

You can take Bactrim with or without food. Taking it with food can help decrease the side effects of nausea and vomiting. Notify your provider if you develop:

• Hives
• Rash
• Joint pain or swelling

These can be signs of an allergic reaction. Not all medications are right for everyone. Bactrim may not be right for you if you have any of the following health conditions:

• Diabetes
• Pregnancy
• Breastfeeding
• Alcoholism
• Liver disease
• Kidney disease
• Allergy to sulfa drugs
• Anemia
• Certain blood disorders
• AIDS

It should also not be combined with certain medications like blood thinners, methotrexate, certain heart medications, and others. Discuss your health history with your provider to avoid any potential issues.

The bottom line – Bactrim can treat bacterial sinus infections

Sinus infections are typically caused by viruses and don’t require treatment with antibiotics. In those cases, symptomatic treatment such as cool mist humidifiers, warm compresses, nasal spray, decongestants, and over-the-counter pain relievers can help with symptoms. 

If your infection is bacterial, Bactrim is no longer a typical choice of antibiotic, although it technically remains an option. Contact your healthcare provider if:

• Your symptoms last longer than 10 days without any improvement
• Symptoms get worse rather than better
• Symptoms went away and returned within a short period of time
• You have a fever lasting longer than three to four days

If you are prescribed Bactrim and need help with the prescription cost, SingleCare has coupons to help. Bactrim coupons can help cut the cost of your prescription. Coupons are also available for Bactrim DS.