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Pharmacology · patient case question

What modification to the extraction is required because of the cetirizine?

Patient case: Medication review before an extraction

Patient: Male, 66 years old

Chief complaint: “This broken tooth needs to come out.”

History: Coronary stent placed two years ago; on aspirin 81 mg and clopidogrel. Seasonal allergic rhinitis, takes cetirizine. Generalised anxiety, takes buspirone.

Findings: Non-restorable tooth #30. No swelling. Blood pressure 128/78 mmHg.

  1. Halve the local anaesthetic dose
  2. No modification is required
  3. Avoid epinephrine in the local anaesthetic
  4. Antibiotic prophylaxis
Show answer and explanation

Correct answer: B. No modification is required

  • A. There is no basis for reducing anaesthetic dose. Dose limits are governed by weight and by cardiovascular and hepatic status.
  • B. CORRECT. Cetirizine has no clinically meaningful interaction with local anaesthetics, vasoconstrictors, analgesics or antibiotics used in dentistry, and does not affect haemostasis or healing. No modification is needed. The only practical note is that mild xerostomia can occur, though far less than with first-generation agents.
  • C. Epinephrine restriction applies to uncontrolled hyperthyroidism, unstable cardiovascular disease, cocaine or methamphetamine use, and to non-selective beta-blocker therapy — not to antihistamines.
  • D. Prophylaxis is determined by cardiac and immune status, not by antihistamine use.

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