foods to avoid when taking trimethoprim

Foods To Avoid When Taking Sulfamethoxazole/Trimethoprim

Antibiotics are common to treat infections and are often used in combinations to provide results and treat better. Many foods interact with the medicines you take and affect their results in one way or the other, so you should avoid them. Sulfamethoxazole and Trimethoprim are common combinations of antibiotics, so let’s see what foods should be avoided when taking these medicines.

What Is Sulfamethoxazole/Trimethoprim Used For?

Sulfamethoxazole and Trimethoprim, both are antibiotics that are used for the treatment of many bacterial infections such as urinary tract infections, bronchitis, shigellosis, ear infections, etc. This medicine combination eliminates the bacteria from the body responsible for causing infections.

Let’s see what is the ideal dosage of this medicine.  

What Is The Dosage Of Sulfamethoxazole/Trimethoprim?

These medicines are available in tablets and suspension forms. Consume this combination of medicines twice a day, with a glass of water. The ideal dose of this combination of Sulfamethoxazole/Trimethoprim for adults is:

  • 800 mg Sulfamethoxazole (1 tablet)
  • 100-200 mg Trimethoprim (1 tablet)

For urinary tract infections: Take 200 mg of trimethoprim 2 times a day.

Preventing infections: 100 mg of trimethoprim once a day.

Now let’s discuss the important question what should you avoid eating while taking these antibiotics?

Foods To Avoid When Taking Sulfamethoxazole / Trimethoprim

When you are on antibiotics like Sulfamethoxazole / Trimethoprim, you should avoid some foods as they affect the absorption of the medicine or reduce its effectiveness.

1- Calcium Containing Foods

Excess consumption of calcium with Sulfamethoxazole / Trimethoprim can interfere with their absorption. If you want to take calcium, go for fermented dairy products till you are taking medication.

2- High Acidic Foods

It is recommended to avoid foods with high acidic content such as citrus fruits like oranges, sodas, and tomatoes as they decrease the amount of antibiotic medicine absorbed in the body.

3- Grapefruit and its related products

Avoid consuming grapefruit or its juice or any product containing it because it contains some compounds like furanocoumarins which interfere with the absorption of Sulfamethoxazole / Trimethoprim reducing its function.

4- Fortified Foods

These foods are also fortified with calcium and cause a similar issue as food with natural calcium in them.

5- Alcohol

Consumption of alcohol with these medicines can increase the chance of some side effects.

Foods To Eat When Taking Sulfamethoxazole / Trimethoprim

1- Fermented Foods

Fermented foods contain healthy bacteria like Lactobacilli that helps in restoring gut microbiota. Some common examples are:

  • Yogurt
  • Cultured milk
  • Cheese
  • Fermented soybean milk
  • Kombucha
  • Kimchi
  • Sauekraut

2- Prebiotics

Prebiotic foods are helpful for gut bacteria. The majority of high-fiber containing foods are prebiotics. Some foods that are prebiotic include:

  • Chicory roots
  • Kefir
  • Yogurt
  • Garlic
  • Onion
  • Bananas
  • Apple
  • Asparagus
  • Barley
  • Oats

3- Probiotics

Probiotics are good for your body as they maintain healthy microorganisms The foods containing probiotics are:

  • Kefir
  • Yogurt
  • Miso
  • Tempeh
  • Kimchi
  • Milk

4- High Fiber Foods

Fiber-rich foods help in restoring healthy gut bacteria. Some high-fiber foods are:

  • Whole grains
  • Nuts
  • Seeds
  • Beans
  • Lentils
  • Banana
  • Apples
  • Brocolli
  • Avocados
  • Peas


Sulfamethoxazole and Trimethoprim, both are antibiotics that are used for the treatment of many bacterial infections. It is advised to avoid taking high-calcium foods, highly acidic foods, citrus fruits like orange and grapefruit, and alcohol with Sulfamethoxazole and Trimethoprim. These foods interfere with the absorption of the medicine, decreasing its absorption and effectiveness, and should be avoided for a while when you are taking the antibiotics.


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