Does Macrobid (Nitrofurantoin) Cause Sun Sensitivity Reactions?

Answer

Nitrofurantoin is typically not associated with a high risk of developing a photosensitivity reaction. Having said that, there are rare reports of these reactions with nitrofurantoin, but it is currently unknown if the reactions experienced were due to the medication, or if other factors were involved.

How Do Sun-Sensitivity Reactions Work?

The exact mechanism behind drugs causing photosensitivity is unknown but it is generally thought that it has something to do with increasing the amount of radiation our skin absorbs from both UV and visible light. If skin reactions do occur due to medication use, the response is variable and highly patient-specific.

The most common reaction is a more severe than usual sunburn as well as an increased likelihood of getting a sunburn. Other reactions can include brown spots on your skin, redness, and tenderness. The vast majority of skin reactions are minor and reversible after drug discontinuation. Very rarely they can be more serious. 

Common Culprits

In terms of antibiotics that have well-known photosensitivity effects, the following are the most common culprits: Sulphonamides (e.g. Bactrim), nalidixic acid, fluoroquinolones and tetracycline.

Final Words

While nitrofurantoin isn't generally considered to put you at a high risk of photosensitive reactions, care should be taken to protect yourself from the sun, just to be safe.

It is recommended to avoid direct sun exposure, wear protective clothing and use a high-factor sunscreen. In addition, it is important to note, as mentioned above, that photosensitive drug reactions can occur from both UV and visible light. Therefore, it is important to avoid tanning beds in addition to direct daylight exposure.