Healthy Living

Did You Know That Bactrim Can Treat Multiple Infections?

Did You Know That Bactrim Can Treat Multiple Infections?

Key Takeaways

  • What is Bactrim?
  • The Uses of Bactrim
  • Who should avoid taking it?
  • Dosage

Bacteria are microorganisms that thrive in the environment. Bacteria are small microscopic organisms, but that 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, generic antibiotics are the class of medications prescribed by health practitioners. 

Antibiotics curb the growth of the bacterial cells and prevent them from multiplying or spreading to other people. 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 diseases. 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 it works

Sulfamethoxazole and trimethoprim both drugs reduce the ability of some bacteria to utilize folic acid which is required for growing. Dihydrofolic acid and tetrahydrofolic acid are forms of folic acid. They are used by bacterial and human cells for producing 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 synthesis of bacterial proteins is interrupted and the combination of both drugs is more effective than a single drug alone.

This product was approved by the FDA in 1973.  Other brand names are Bactrim DS, 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 years due to its risk of side effects. Bactrim is 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, mainly, sulfamethoxazole and trimethoprim. In case you are not sure about your allergies, speak to your doctor so that he or she can advise you about your condition. Older patients who are on multiple prescriptions need to be careful if they are taking Bactrim. Before administering any Bactrim medication to the elderly, a careful analysis of the patients' health and medication history must be made by the doctor.

Treatment Using Bactrim

The combination of sulfamethoxazole and trimethoprim makes Bactrim effective against a vast range of bacterial infections.

  • Ear infection: Bactrim can treat infections in the middle ear (acute otitis media). It works against middle ear infections caused in children by Streptococcus pneumoniae and Haemophilus influenzae
  • Respiratory tract infection: Bactrim also treats respiratory tract infections like bronchitis (infection of the mucous membrane in 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 jiroveci 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 (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 brining trimethoprim with ethanol. Bringing both in contact may cause aweful symptoms which includes fast pulse, redness under the skin, shivering, sickness, regurgitating. Using alcohol and antibiotics together can make the person extremely uncomfortable and tired increasing the side effects. It can also lead to nausea, flushing, regurgitating, headaches. There have been cases of patients having heart palpitations, shortness of breath. Doctors advise patients not to taken 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 sulphonamide antibiotic.
  • Common side effect: After taking Bactrim, common symptoms like loss of appetite, vomiting, mild nausea, dizziness, lethargy, and buzzing sound in the ears may be experienced.
  • Rare side effect: There are symptoms that indicate the need of 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 and nausea, paleness or yellowing of the skin and sclera (white outer covering of the eye), as well as having trouble in breathing.

Patients with liver or kidney diseases should consult their medical practitioners before taking any medication. 

Other side effects of Bactrim may include:

See your doctor right away or seek medical emergency if you experience:

  • Fever or chills
  • Trouble breathing
  • Unusual bruising or bleeding
  • Muscle pain
  • Purple or reddish spots on the skin
  • Paleness, depression
  • Prolonged diarrhea with fever and 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 call a doctor.


In order to make sure that the medicine is working properly 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 skin rash or a severe skin reaction, call the doctor right away.

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

Bactrim may 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, sudden weakness, it is necessary to check with the doctor since these might be symptoms of serious intestinal infection. 

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

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 for folate deficiency. Bactrim should not be used to treat Pneumoystis jiroveci pneumonia if the patient is already using leucovorin.


Dosage form: Tablet

Dose varies for different patients. The number of doses taken each day, time between the doses depends on the medical problem and the medicine the patient is using.

The antibiotics tablets are round and white. They contain 400mg of sulfamethoxazole and 80 milligram of trimethoprim. The bactrim ds dosage tablets are oval and white. They contain 800mg of sulfamethoxazole and 160mg of trimethoprim.

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

Patients taking oral liquid should use a measuring spoon or other devise so that each dose is measured accurately. In order to clear up the infection completely use the medicine throughout the treatment. If even the person feels better after a few days still this medicine should not be stopped till 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 double dose.

Overdose of bactrim can cause following signs and symptoms:

  • Fluctuating pain in the abdomen
  • Anorexia
  • Headache, dizziness
  • Drowsiness, unconsciousness
  • Fever
  • Anemia or other blood disorders
  • Depression or 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 the reach of children.

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 Interaction

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. Methanamine causes acidic urine and sulfonamide in sulfamethoxazole can crystallize in acidic urine. Hence it should not be used together.

Sulfamethoxazole/ trimethoprim may also cause increase blood levels of phenytoin which may lead to side effects such as dizziness and reduced attention. It may also cause increase in blood levels of digoxin may lead to serious side effects.  Sulfamethoxazole/ Trimethoprim received in combination with any of these drugs viz. divalproex, valproic acid, methotrexate, pyrimethamine, triamterene, trimetrexate may cause anemia due to reduction in folic acid. When combined with ACE inhibitors it may cause increased blood levels of potassium.

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 infection as it is caused by a fungus called Candida albicans. The use of Bactrim in a fungal infection is dangerous since it will just make the infection worse by causing yeast overgrowth. An antifungal drug is the most suitable medication to treat 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 like Bactrim or Septra, which is not a good option during pregnancy as it can 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 club foot.

Sulfonamides may 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. Hence this medicine should not be used in pregnancy.

When Not to Use

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

  • extreme liver or kidney problem
  • anemia (deficiency in red blood cells)
  • asthma or other severe allergies
  • thyroid disorder
  • pregnant
  • breastfeeding a baby