A nurse is educating a patient who has been prescribed tetracycline to treat their acne vulgaris. Which instruction should the nurse prioritize to prevent photosensitivity reactions?

A. Apply sunscreen with at least SPF 15 and wear protective clothing when outdoors: Tetracycline can cause photosensitivity, making the skin more prone to sunburn and rashes. Using sunscreen and protective clothing helps prevent harmful reactions, making this the priority safety instruction. B. Take the medication with dairy products to reduce stomach upset: Dairy can bind tetracycline and decrease its absorption, reducing effectiveness. While managing stomach upset is important, it does not prevent photosensitivity. C. Increase sun exposure gradually to build tolerance to sunlight: Increasing sun exposure can worsen photosensitivity reactions. Patients should avoid direct sunlight while taking tetracycline. D. Limit fluid intake to avoid dilution of the medication in the bloodstream: Limiting fluids is unsafe and unnecessary. Adequate hydration is important to reduce gastrointestinal irritation and support kidney function while taking tetracycline.