The nurse is caring for a client who is prescribed to treat acne vulgaris. Which Of the following Options are complications of this medication? (Select All That Apply.)

A. Incorrect: Opioid toxicity triad (respiratory depression, coma, pinpoint pupils) is not related to doxycycline. B. Incorrect: Achilles tendon rupture is a complication of fluoroquinolones, not doxycycline. C. Correct: Photosensitivity (increased sunburn risk) is a known side effect of doxycycline. D. Correct: Doxycycline can cause permanent tooth discoloration if taken in children under 8 years old or during pregnancy.