Bactrim for Sinus Infection: What to Know

Ayesha Gulzar, PharmD
·8 min read

Medically reviewed by Lindsay Cook, PharmD

Bactrim is an effective combination of two antibiotic drugs, sulfamethoxazole, and trimethoprim, a combination which is also known as a "co-trimoxazole."

This brand-name product is classified as a sulfonamide antibiotic and is available by prescription only.

Bactrim has numerous Food and Drug Administration (FDA)-approved uses for adults and children 2 months and older, such as pneumonia, bronchitis, and infections of the urinary tract, ears, and intestines, in addition to various types of respiratory infections.

While not FDA-approved, Bactrim can also used to treat sinusitis, otherwise known as a sinus infection.

However, Bactrim is no longer a first-line treatment for a sinus infection and is not currently a commonly prescribed choice.

Instead, healthcare providers may prescribe Doxy-100 (doxycycline) or Levaquin (levofloxacin).

This article will review Bactrim, its uses, side effects, dosing requirements, and its role in treating sinus infections.

<p>Getty Images / damircudic</p>

Getty Images / damircudic

Understanding Bacterial Infections

Bacterial infections were the second leading cause of death globally in 2019.

Microorganisms (bacteria) cause bacterial infections. Bacteria are transmitted to humans through contaminated air, water, food, or other infected living organisms.

Bacteria may release harmful chemicals called toxins. Toxins can damage tissues and cause symptoms of infection such as pain, inflammation, swelling, and even organ damage.

Untreated bacterial infections can spread rapidly and may lead to life-threatening conditions.

Common bacterial infections include urinary tract infections (UTIs), respiratory infections, sexually transmitted infections (STIs), and skin infections.

Commonly Used Antibiotics

The most commonly used drugs to treat bacterial infections belong to a class of drugs called antibiotics.

Antibiotics work against bacterial infections by killing the bacteria or by inhibiting their growth and multiplication in the body.

Antibiotics are effective against bacterial infections only.

Examples of commonly used antibiotics include:

What Is Bactrim?

Bactrim is an orally administered, brand-name antibiotic containing sulfamethoxazole, an antimicrobial, and trimethoprim, a dihydrofolate reductase inhibitor antibacterial.

This combination of active ingredients is known as co-trimoxazole, which also can be abbreviated as TMP-Sulfa.

Bactrim has been used to treat several types of bacterial infections related to methicillin-resistant Staphylococcus aureus (MRSA).

It can also treat bacterial sinus infections caused by Moraxella catarrhalis (M. catarrhalis), Streptococcus pneumoniae (S. pneumoniae), and other bacterial infections.

This medication treats the following bacterial infections in adults and children 2 months and older:

Off-Label Uses

Bactrim may also be prescribed for various off-label uses (prescribing a drug for a non-FDA-approved use), including:

Sulfamethoxazole/Trimethoprim in Other Products

The combination of trimethoprim and sulfamethoxazole is available in brand-name form beyond Bactrim.

For example, commonly prescribed brands include Septra and Septra DS.

The combination of trimethoprim and sulfamethoxazole is also available as a generic drug in oral and injectable form.

How It Works

Sulfamethoxazole and trimethoprim work together to accomplish the following:

  1. Blocking the biosynthesis of nucleic acids and proteins, a process essential for the growth of bacteria

  2. The production of a bactericidal, which is the killing of bacteria

Bactrim for Sinus Infections

Historically, Bactrim has been used as a treatment option for bacterial sinus infections.

Despite this, Bactrim is no longer a first-line treatment for a sinus infection (when antibiotics are necessary) and is no longer a commonly prescribed choice.

Now, healthcare providers will likely prescribe Doxy-100 (doxycycline) or Levaquin (levofloxacin) if a person's symptoms do not improve after using alternative treatment options or antibiotics.

Dosing Bactrim for a Sinus Infection

Your healthcare provider will prescribe the appropriate Bactrim dose to treat your symptoms.

Orally administered Bactrim for a sinus infection comes in two strengths:

  • Bactrim: 400 milligrams (mg) of sulfamethoxazole and 80 mg of trimethoprim

  • Bactrim DS (double-strength): 800 mg sulfamethoxazole and 160 mg trimethoprim

Your specific dosage, however, may be adjusted on various factors, such as weight, age, or kidney function.

A healthcare provider may administer one to two tablets of Bactrim DS or Bactrim every 12 to 24 hours.

The dose for children, however, is based on weight and should never be given to children younger than 2 months old.

How Quickly Will Bactrim Work?

Bactrim is rapidly absorbed after oral administration, producing its effects within one to four hours.

The mean half-lives (the time half of the drug's active substance takes to exit the body) of sulfamethoxazole and trimethoprim are 10 and eight to 10 hours, respectively.

However, people with severely impaired kidney function cause have an increased half-life and require dose adjustment.

Sulfamethoxazole and trimethoprim are primarily secreted from the body through urine.

Side Effects and Precautions

Bactrim is a generally safe antibiotic.

However, several common and potentially severe side effects are associated with this combination product, as discussed below.

Common Side Effects

Common side effects associated with the use of Bactrim include:

Severe Side Effects

While rare, more severe side effects associated with the use of Bactrim include:

Warnings and Precautions

Consult your healthcare provider before taking Bactrim if you currently experience or have ever had any of the following medical conditions:

Your healthcare provider will monitor you closely for any adverse effects.

Safe Consumption Guidelines

The following guidelines should be observed to achieve the safe and effective use of Bactrim:

  • Bactrim is available as a tablet and a suspension (liquid) to take by mouth.

  • Take two times or up to four times a day. Take Bactrim exactly as directed, and do not take more or less than prescribed.

  • Bactrim will improve your symptoms during the first few days of treatment. Call your healthcare provider if you do not feel well, or your symptoms worsen.

  • Mix or shake the liquid dosage form well before each use.

  • Drink plenty of fluids when taking Bactrim to avoid stone formation.

  • Do not use in pediatrics under 2 months of age.

  • Avoid unnecessary or prolonged exposure to sunlight, wear appropriate clothes and sunglasses, and use sunscreen to avoid sensitivity to light.

Complete your prescription and take Bactrim as long as prescribed, and only stop taking it after asking your healthcare provider, even if you feel well.

If you stop taking Bactrim too soon or skip, doses may cause bacterial resistance and make antibiotics ineffective for future needs.

Alternative Treatment Options

Antibiotics are commonly prescribed to treat sinus infections. However, sometimes, it is possible to avoid antibiotics and try alternative methods to improve the symptoms.

Some ways to help relieve sinus pain and pressure include:

  • Clean nasal passages every day

  • Put a warm compress over the nose and forehead

  • Use a decongestant

  • Nasal saline sprays

  • Inhale steam

  • Over-the-counter (OTC) painkillers and cold and cough medicines can help you feel better

You can also prevent the contamination and spread of sinus infections by:

  • Wash or clean your hands regularly

  • Vaccination for flu and pneumococcal vaccine.

  • Avoid contact with people who have colds or other upper respiratory infections

  • Avoid smoking

  • Use a humidifier

  • Sleep with an elevated head

Summary

First approved in 1968, Bactrim, a combination of trimethoprim and sulfamethoxazole, treats various bacterial infections in adults and children 2 months and older.

Bactrim has been a drug of choice for sinusitis for decades. It starts working within a few hours after oral administration. However, Bactrim is not a first-line treatment for a sinus infection and is no longer a commonly prescribed choice.

Despite its effectiveness and worldwide use, it has some severe side effects. You can use it with your healthcare provider's advice in case of any other disease or taking other medications.

Avoid when pregnant or breastfeeding as it may harm the baby.

Always use this drug as prescribed for the specified period to reduce the chances of developing antibiotic resistance.

Frequently Asked Questions

Are younger or older people at risk of developing more serious side effects with Bactrim?

Older adults are more prone to the side effects of Bactrim, such as skin reactions, blood disorders, easy bleeding, bruising, and a high potassium blood level.

People with renal problems and folate deficiency also increase the risk of side effects.

For how long is Bactrim present in the body?

Bactrim drug traces can be found in the urine up to three days after an oral dose.

Read the original article on Verywell Health.