Pharmacology · patient case with 1 question
Anxious patient asking about sedation before an extraction
Patient: Female, 34 years old
Chief Complaint: “I need something to calm me down — and honestly I would rather not remember any of it.”
Background: Severe dental anxiety. No systemic disease, no medications, no allergies. Non-smoker, no alcohol or recreational drug use. Will be driven home.
Vital Signs: BP 134/84 mmHg · HR 96 bpm · RR 18
Findings: Non-restorable tooth #29 requiring simple extraction. Otherwise healthy dentition.
Question 1
Which drug class produces the ANTEROGRADE AMNESIA she is describing?
Show answer and explanation
Correct answer: C. Benzodiazepines, such as diazepam, midazolam and triazolam
- A. NSAIDs are analgesics and anti-inflammatories acting on cyclo-oxygenase. They have no CNS sedative or amnestic effect.
- B. SSRIs are antidepressants and take weeks to reach effect. They produce no acute sedation and no amnesia, and they have no role in procedural anxiety management.
- C. CORRECT. BENZODIAZEPINES enhance GABA-A chloride channel opening frequency, and they carry four properties: ANXIOLYSIS, SEDATION, MUSCLE RELAXATION and ANTICONVULSANT action — plus ANTEROGRADE AMNESIA, the loss of memory for events occurring AFTER administration. Memories laid down before the drug are unaffected. Midazolam and triazolam produce it most reliably; diazepam does so at higher doses.
- D. Beta-blockers blunt the peripheral autonomic signs of anxiety — tachycardia, tremor, sweating — but leave the subjective experience and memory formation intact.
Note: Anterograde amnesia is clinically USEFUL in sedation rather than an adverse effect: the patient does not consolidate memory of an unpleasant procedure and returns more willingly. Flumazenil is the reversal agent; watch for re-sedation as it is shorter-acting than midazolam. Buspirone, by contrast, is anxiolytic but non-sedating, non-amnestic and useless acutely.