Healthy Living

Did You Know That Bactrim Can Treat Multiple Infections?

Did You Know That Bactrim Can Treat Multiple Infections?

Bacteria are microorganisms that thrive in the environment, but they are not always harmful. There are a number of vital functions that are performed by bacteria, which are essential for our day-to-day living. However, sometimes, these bacteria may leave harmful strains on or inside our body. When a bacterium leaves such harmful strains and the person's immune system cannot fight it off, bacterial infections can take place.

A number of diseases such as food poisoning, meningitis, and pneumonia are a result of such bacterial attacks. The infections caused by these bacteria can be treated using appropriate medications. To fight these bacterial infections, certain antibiotics are prescribed by healthcare providers. 

Antibiotics curb the growth of bacterial cells and prevent them from multiplying or spreading. It is important to take the appropriate dosage of these antibiotics since there are many strains of bacteria present in the body that can lead to secondary infections. 

What is Bactrim?

Generic name: Sulfamethoxazole/Trimethoprim

Bactrim is a brand name of an antibiotic that is used to treat many bacterial infections. It is a combination of the two generic antibiotics called sulfamethoxazole and trimethoprim. Both of these antibiotics are used to control various bacterial infections.

Sulfamethoxazole (SMX or SMZ)

Sulfamethoxazole is an effective medication against gram-positive and gram-negative bacteria. This antibiotic can be combined with another antibiotic or as a separate component to treat bacterial infections. Sulfamethoxazole is commonly used as a treatment for urinary and respiratory tract infections, which are bacterial of origin.

Trimethoprim (TMP)

TMP is used for the treatment of urinary bladder infections, traveler’s diarrhea (a stomach and intestinal infection), and middle ear infections.

How does it work?

Sulfamethoxazole and trimethoprim are both drugs that reduce the ability of some bacteria to utilize folic acid, which is required for their growth. Dihydrofolic acid and tetrahydrofolic acid are forms of folic acid. They are used by bacterial and human cells to produce proteins.

Sulfamethoxazole disrupts the production of dihydrofolic acid whereas trimethoprim disrupts the production of tetrahydrofolic acid by inhibiting the enzyme responsible for making tetrahydrofolic acid from dihydrofolic acid. Hence, by combining both drugs, the steps required for bacterial protein synthesis are interrupted. Moreover, the combination of both drugs is more effective than a single drug alone.

This antibiotic was approved by the FDA in 1973. Other brand names of this antibiotic are Bactrim DS and Sulfatrim Pediatric.

Uses of Bactrim

Bactrim is used for the treatment of many diseases. They include:

Who should avoid taking it?

Bactrim is not suitable for children's use under the age of two due to its risk of side effects. Bactrim is also not used for the treatment of viral diseases such as the common cold or flu. If used unnecessarily or taken more than the prescribed dosage by the doctor, it can cause a decline in its effectiveness.

Bactrim should not also be consumed by those who are allergic to its primary components, which are sulfamethoxazole and trimethoprim. If you are unsure about your allergies, speak with your doctor so that he or she can advise you about your condition.

Older patients who are on multiple drug prescriptions need to be careful when they are taking Bactrim. Before administering any Bactrim medication to the elderly, a careful analysis of their health and medication history must be made by the doctor.

Treatment Using Bactrim

The combination of sulfamethoxazole and trimethoprim makes Bactrim effective against a range of bacterial infections such as:

  • Ear Infection: Bactrim can treat infections that affect the middle ear (acute otitis media). It works against middle ear infections seen in children. Most ear infections are caused by Streptococcus pneumoniae and Haemophilus influenzae.
  • Respiratory Tract Infection: Bactrim also treats respiratory tract infections such as bronchitis, which is an infection of the mucous membrane of the bronchial tubes. Bactrim helps when chronic bronchitis worsens and caused by Streptococcus pneumoniae or Haemophilus influenzae.
  • Urinary Tract Infection (UTI): Most urinary tract infections in children and adults can be treated using Bactrim. UTIs caused by E. coli, Klebsiella, Enterobacter, Morganella morganii, Proteus mirabilis, and Proteus vulgaris can be treated using Bactrim.
  • Traveler’s Diarrhea and Shigellosis: Bactrim treats these infections with symptoms of stomach cramps, diarrhea, and fever.
  • Acne vulgaris: Bactrim is also used to treat acne and its other features such as blackheads, whiteheads, pimples, or blemishes.
  • Pneumonia: Pneumocystis jirovecii is a fungus that can cause pneumonia, especially in people with weak immune systems. Bactrim is one of the most effective antibiotics for the treatment of this kind of pneumonia.
  • Sepsis: Bactrim is also used for the treatment of sepsis, which is a disease caused by a reaction to an infection or swelling of the whole body.

Bactrim and Alcohol

Bactrim is used to treat various infections and alcohol affects the way the body processes various medications. Ask the specialist before taking alcohol. Bringing both in contact may cause awful symptoms, which include a fast pulse, skin redness, shivering, sickness, and regurgitation.

Using alcohol and antibiotics together can make the person extremely uncomfortable and tired increasing the side effects. It can also lead to nausea, flushing, regurgitation, and headaches. There have been cases of patients having heart palpitations and shortness of breath. Doctors usually advise patients not to take alcohol with any antibiotics.

Side Effects of Bactrim

  • Sulfa Allergies: Sulfa medications can trigger a reaction in people who are sensitive to sulfonamides since Bactrim is a sulfonamide antibiotic.
  • Common Side Effects: After taking Bactrim, common symptoms such as loss of appetite, vomiting, mild nausea, dizziness, lethargy, and buzzing sound in the ears may be experienced.
  • Rare Side Effects: There are symptoms that indicate the need for an immediate medical attention. The symptoms that you should watch out for are swelling and pain in the tongue or face, itching, skin rashes, joint aches, consistent fever, nausea, paleness or yellowing of the skin and sclera (white outer covering of the eye), as well as trouble breathing.

Patients with liver or kidney diseases should consult their healthcare provider before taking any type of medication. 

Other side effects of Bactrim may include:

See your doctor right away or seek immediate medical care if you experience the following:

  • Fever or chills
  • Trouble breathing
  • Unusual bruising or bleeding
  • Muscle pain
  • Purplish or reddish spots on the skin
  • Paleness
  • Depression
  • Prolonged diarrhea with fever
  • Stomach cramps

If a person experiences difficulty in breathing, swelling of the face, lips, tongue, or throat, and develops hives after taking the medication, he or she should immediately seek medical attention.


To make sure that the medicine is properly working, it is better to get the progress of the patient checked by the doctor at regular visits. Blood and urine tests can be done to check for unwanted side effects.

This medicine should be avoided during pregnancy. If the patient gets a skin rash or a severe skin reaction, call the doctor right away.

Other symptoms may include pale, yellow, or purple spots on the skin, sore throat, muscle pain, fever, cough, and trouble breathing. If this medicine is taken at higher doses or taken for a longer period of time, it may cause the platelet count to become low. Platelets are required for proper blood clotting, so the person may bleed or get infections when platelets are low. Hence, it is important to speak with the doctor if such issue arises.

Bactrim may also cause diarrhea. Sometimes, mild diarrhea continues or gets worse. This may happen two months or more after the medicine is stopped. Hence, check with the doctor before treating diarrhea. If the child experiences abdominal or stomach cramps, bloating, watery and severe diarrhea, nausea, vomiting, unusual tiredness, and sudden weakness, it is necessary to check with the doctor since these might be symptoms of a serious intestinal infection. 

This medicine can also cause anaphylaxis, which is a life-threatening medical emergency. Look for allergic reactions such as rashes, itching, and swelling of the face, tongue, and throat. Bactrim may also cause electrolyte problems such as low sodium in the body and high potassium in the blood.

A doctor should be contacted if any of the symptoms such as confusion, weakness, irregular heartbeat, numbness or tingling in the hands, feet, and lips occur. Patients on anticonvulsant therapy may be at risk of folate deficiency. Bactrim should not be used for the treatment of Pneumocystis jirovecii pneumonia if the patient is already using leucovorin.


Dosage Form: Tablet

The dose varies for every patient. The number of doses taken each day and the time between the doses depends on the medical problem and the medicine the patient is using.

Bactrim tablets are round and white. They contain 400 mg of sulfamethoxazole and 80 mg of trimethoprim. Bactrim DS tablets are oval and white. They contain 800 mg of sulfamethoxazole and 160 mg of trimethoprim.

Bactrim in tablet form should be taken through the mouth with a glass of water and as prescribed by the doctor. It should be taken with plenty of water to lower the risk of kidney stone formation unless otherwise advised by the doctor. If the medication causes an upset stomach, then it should be taken with food.

Patients taking an oral liquid should use a measuring spoon or another device, so that each dose is accurately measured. To completely clear up the infection, use the medicine throughout the treatment. Even if you feel better after a few days, do not stop taking the medicine until the course is complete or else the symptoms may return.

If a dose is missed, it should be taken as soon as possible. If it is almost time for the next dose, then skip the missed dose and get back to the regular dosing schedule. Do not take a double dose.

A Bactrim overdose can cause the following symptoms:

  • Fluctuating pain in the abdomen
  • Anorexia
  • Headache
  • Dizziness
  • Drowsiness
  • Unconsciousness
  • Fever
  • Anemia or other blood disorders
  • Depression
  • Confusion
  • Jaundice

Use and Storage

The medicine should be stored in a closed container at room temperature. It should be kept away from heat, moisture and direct light. It should be kept out of children's reach as well.

How to Take the Medication

A complete antibiotic course of Bactrim should be fully taken according to prescription. One may feel better after taking the medication for some time, but the bacteria may not be completely killed. Skipping a dose or taking it irregularly can cause further infection, which can be resistant to the antibiotic that you are currently taking.

Drug Interactions

Sulfamethoxazole/trimethoprim may possibly lead to bleeding by enhancing the blood-thinning effects of warfarin. The sulfonamides present in sulfamethoxazole can increase the metabolism of cyclosporine causing it to be less effective and lead to kidney damage. Methenamine causes an acidic urine and sulfonamide in sulfamethoxazole can crystallize in acidic urine. Hence, it should not be used together.

Sulfamethoxazole/trimethoprim may also cause an increase in blood levels of phenytoin, which may lead to side effects such as dizziness and reduced attention. It may also cause an increase in the levels of digoxin in the blood leading to serious side effects.

When sulfamethoxazole/trimethoprim is received in combination with any of the following drugs, it may cause anemia due to a reduction in folic acid:

  • Divalproex
  • Valproic acid
  • Methotrexate
  • Pyrimethamine
  • Triamterene
  • Trimetrexate 

When combined with ACE inhibitors, it may cause increased levels of potassium in the blood.

In total, almost 422 drugs interact with Bactrim, which includes 1,580 brands and generic names. Some of the common drugs are:

Disease Interaction 

Bactrim (sulfamethoxazole/trimethoprim) interacts with 12 diseases. They are:

  • Hematologic toxicity
  • Hypersensitivity reaction
  • Liver disease
  • Porphyria
  • Renal dysfunction
  • Folate deficiency
  • Colitis
  • Crystalluria
  • Hemodialysis
  • Dialysis
  • Urinary obstruction

Can Bactrim treat yeast infections?

Bactrim is not used for the treatment of yeast infections as these infections are caused by the fungus called Candida albicans. The use of Bactrim in a fungal infection is dangerous since it will just make the infection worse by causing a yeast overgrowth. An antifungal drug is the most suitable medication for the treatment of yeast infections.

Pregnancy and Breastfeeding

Bactrim is harmful when used during pregnancy. This medication should not be used during pregnancy as it may cause serious effects on the unborn infant.

The drugs sulfamethoxazole and trimethoprim can also be passed in the mother's breast milk and may cause harm to the breastfeeding baby by causing kernicterus. Trimethoprim is found as an ingredient in drugs such as Bactrim or Septra, which is not a good option during pregnancy as it tends to block the effect of folic acid.

According to some epidemiologic research, exposure to Bactrim during pregnancy can cause congenital abnormalities in the baby such as cardiovascular malformation, neural tube defects, urinary tract defects, oral clefts, and clubfoot.

Sulfonamides may also cause bilirubin to be displaced into the infant’s blood from proteins. This displacement may lead to jaundice and to a dangerous condition called kernicterus in infants. 

When Not to Use

You should not use this medication if you have any of the following:

  • Extreme liver or kidney problem
  • Anemia (a deficiency in red blood cells)
  • Asthma or other severe allergies
  • Thyroid disorder
  • Pregnant
  • Breastfeeding a baby