How long do you have to wait before sun exposure after taking Bactrim? 

How long do you have to wait before sun exposure after taking Bactrim? 

You need to wait for at least 3 days after your last Bactrim dose before stepping out in the sun. Bactrim is an antibiotic that is considered phototoxic in nature. 

This means that the drug increases your photosensitivity and can enhance sun damage to your skin (1). This is a proven side effect and only those areas of the body are affected which get directly exposed to the sun. 

However, you might not be able to sit at home for 3 days straight, especially if you’re a working person. It is also important to note that you should take Bactrim properly and for as long as your doctor has recommended. 

Antibiotic doses should not be skipped, as doing so can affect your desired therapeutic goals. It is also important to make sure you don’t pair Bactrim with anything that can slow down your body’s own ability to recover, like alcohol or any other drug that may suppress your immunity. 

Tips to prevent Bactrim-induced photosensitivity reactions 

There are some tips that can help prevent excessive sun damage associated with the use of Bactrim. These include:

  • Wear a sunscreen
  • Use hats and sunglasses 
  • Stay in the shade

Wear a sunscreen 

It is best to wear a broad-spectrum sunscreen with SPF 15 or more. This is recommended by the Centers for Disease Control and Prevention (CDC) as good sunscreen can significantly protect your skin from getting exposed to direct radiation coming from the sun. 

This way, there won’t be a direct reaction after taking Bactrim. However, make sure you’re using the right sunscreen. You can consult a dermatologist to make sure you’re using the right SPF and the right kind of sunscreen for your skin. 

Use hats and sunglasses 

Hats and sunglasses can be used to protect you from direct sunlight exposure. Studies showed reactions upon direct sun exposure after taking Bactrim. 

If you’re covered in full clothing with a hat and sunglasses, you will most likely stay protected. However, it’s still best to limit your sun exposure and go out only when necessary. 

Stay in the shade

As I just stated, it’s okay to go out during the daytime as long as the sunlight doesn’t hit you directly. Apart from being covered, you can try staying in the shade as much as you can.

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References

1.-

Zhou W, Moore DE. Photosensitizing activity of the anti-bacterial drugs sulfamethoxazole and trimethoprim. J Photochem Photobiol B. 1997 May;39(1):63-72. doi: 10.1016/s1011-1344(96)07468-4. PMID: 9210323. Available from: https://pubmed.ncbi.nlm.nih.gov/9210323/