Final answer:
The nurse should identify that a client with a history of tendonitis would have a contraindication for administering ciprofloxacin, an antibiotic often prescribed for UTIs.
Step-by-step explanation:
The nurse should identify that the contraindication for administering ciprofloxacin is the client statement 'I have a history of tendonitis.' Ciprofloxacin belongs to a class of antibiotics called fluoroquinolones, which can increase the risk of tendonitis and tendon rupture, especially in patients with a history of these conditions. Therefore, prescribing ciprofloxacin to a patient with a history of tendonitis would not be recommended.