Foods and drinks to avoid while taking Bactrim include alcohol and foods high in potassium. In general, Bactrim does not have any major food interactions.
Medically reviewed by Jennie Olopaade, PharmD, RPH
Antibiotics like trimethoprim-sulfamethoxazole (Bactrim) kill bacteria in the body that cause illness. Some foods and beverages, like alcohol, can interact with some antibiotics, reducing their efficacy and creating a risk of toxicity. With Bactrim, the risk of interaction is small unless you have specific medical conditions.
If you choose not to take Bactrim, there are several other antibiotics that you can discuss with a doctor.
While a doctor may not advise you to change your diet, you might choose to avoid some foods and food interactions to help prevent these uncomfortable side effects.
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Many antibiotics come with a warning to avoid alcohol. The evidence that a person should not take Bactrim with alcohol is uncertain.
A 2020 review of studies looked at how alcohol affects the efficacy of specific antibiotics. The review also assessed whether alcohol created a toxic interaction or otherwise affected how the drug worked.
Some antibiotics have a negative interaction with alcohol, so you should avoid it if you drink. Antibiotics that interact with alcohol include:
cephalosporins like cefamandole (Mandol) and cefmetazole (Zefazone)
However, the evidence around alcohol and Bactrim in particular is unclear. There is a minimal risk of adverse reactions. Research data is limited, but alcohol might cause facial flushing when consumed while taking Bactrim.
Some people might also experience indigestion if they consume too many alcoholic beverages. If this affects you, you might also want to avoid alcohol while taking Bactrim as the drug can also cause an upset stomach.
Potassium-rich foods
Bactrim increases the risk of developing hyperkalemia (high potassium) if you have a condition that affects how your body uses potassium or impaired kidney function.
Bactrim can also cause hyperkalemia if you also take angiotensin-converting enzyme (ACE) inhibitors. ACE inhibitors can also raise blood potassium levels. You might want to talk with a doctor about the risks of Bactrim if you take ACE inhibitors such as:
As Bactrim can cause digestive symptoms, like nausea, vomiting, and loss of appetite, you might want to avoid taking it alongside foods that may also upset your stomach.
Some common foods that cause upset stomach are:
caffeinated or fizzy beverages
spicy, fatty, or greasy foods
acidic foods like tomatoes or oranges
Foods not on this list can also cause digestive issues. You can avoid other foods you know can affect you.
Foods to try
You might consider eating prebiotic and probiotic foods when taking Bactrim.
Antibiotics like Bactrim can kill some of the good bacteria in the gut while killing the bad bacteria causing illness. Eating foods that contain good bacteria can help balance the gut.
Probiotics are foods that contain good bacteria. Prebiotic foods don’t contain good bacteria but have complex carbohydrates that help the good bacteria to grow in your gut.
Prebiotic foods include:
asparagus
whole grains
onions
garlic
soybeans
Probiotic foods include:
yogurt
kimchi
tempeh
buttermilk
sourdough bread
Other medications
A doctor might recommend a different antibiotic if you prefer not to take Bactrim.
Alternatives to Bactrim depend on the condition you need to treat. Some examples might be antibiotics in other classes, such as:
Penicillin antibiotics: One example is amoxicillin (Amoxil), which you can take with or without food. You can add another liquid, like milk or fruit juice, to the suspension version. You can continue your usual diet.
Cephalosporin antibiotics: An example is cephalexin (Keflex), which you can take with or without food. You can continue your usual diet.
Macrolide antibiotics: One example is azithromycin (Zithromax) in tablet form, which you can take with or without food. Azithromycin is also available as a suspension (Zmax), which you need to take on an empty stomach. If you take an antacid, ask a doctor or pharmacist how long to wait after the antacid for your azithromycin dose. You can continue your usual diet.
A doctor might recommend a different antibiotic or other treatment not on this list as an alternative to Bactrim.
Summary
Trimethoprim-sulfamethoxazole (Bactrim) is an antibiotic to treat many infections and conditions, including UTIs, chronic bronchitis, and pneumonia.
It is generally safe to take Bactrim with or without food. However, experts recommend drinking plenty of water while taking this medication to help reduce the risk of kidney stones. You might also want to avoid alcohol.
Prebiotic and probiotic foods can help restore healthy gut bacteria after you have finished your course of antibiotics.
If you are at risk for high potassium, consider discussing with a doctor whether Bactrim is safe for you.
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