A 28-year-old client at 26 weeks gestation is sent home from urgent care with doxycycline 100 mg PO twice daily for community-acquired pneumonia. Which is the priority nursing action?

Tetracyclines, including doxycycline, are generally contraindicated in pregnancy beyond approximately 18 to 20 weeks gestation when fetal tooth development begins; effects include permanent yellow-brown tooth discoloration of primary and possibly permanent dentition, enamel hypoplasia, and possible reversible bone growth slowing. They are also linked to maternal hepatotoxicity, especially with high IV doses in the third trimester. Standard nursing response: (1) hold the dose, contact the prescriber to clarify and request a pregnancy-compatible antibiotic; (2) for community-acquired pneumonia in pregnancy, alternatives include a macrolide (azithromycin) or a beta-lactam (amoxicillin, cefuroxime, ceftriaxone) depending on susceptibility and severity; if atypical pathogens are suspected, azithromycin is preferred over doxycycline; (3) pharmacist consult helps ensure all medication exposures are reviewed for pregnancy safety using updated FDA pregnancy and lactation labeling rule (PLLR) information rather than older categories; (4) educate the client and document. The CDC has issued guidance allowing short courses of doxycycline in pregnancy only for confirmed life-threatening tickborne illnesses where the alternative would put the mother at serious risk, but this is an exception, not the default. Administering, increasing the dose, and adding ergot are all unsafe.

Doxycycline is contraindicated in pregnancy; switch to a pregnancy-compatible agent. Hold and clarify before administering. Tickborne life-threatening illness is the rare CDC-allowed exception.