A pharmacy technician is retrieving a medication from the automated dispensing cabinet (ADC) for a patient. The order is for 'metoprolol tartrate 50 mg PO daily'. The ADC displays 'metoprolol succinate ER 50 mg'. What is the most appropriate action for the technician?
- AAlert the pharmacist immediately regarding the discrepancy.
- BAdminister the metoprolol succinate ER 50 mg and inform the nurse.
- CDispense the metoprolol succinate ER 50 mg, as it is the same drug.
- DOverride the ADC to dispense metoprolol succinate ER 50 mg and document it.
Show answer & explanationAnswer & explanation
Correct answer: A. Alert the pharmacist immediately regarding the discrepancy.
Metoprolol tartrate and metoprolol succinate are different salts of the same active drug, metoprolol. They have different pharmacokinetic profiles (tartrate is immediate-release, succinate is extended-release) and are not therapeutically equivalent for a direct dose-for-dose substitution without a prescriber's order. A technician must alert the pharmacist to resolve this therapeutic interchange issue.
Why the other options are wrong
- B. A technician cannot administer medication, and administering the wrong form of the drug is a medication error.
- C. This is incorrect. While both contain metoprolol, they are different salts with different release mechanisms and are not interchangeable without a prescriber's approval.
- D. Overriding the ADC for this type of discrepancy is dangerous and constitutes an unauthorized therapeutic interchange, potentially leading to patient harm.
Therapeutic Equivalence (Metoprolol Salts)
Medications are therapeutically equivalent if they have the same active ingredient, dosage form, strength, and route of administration, and produce the same clinical effect. Different salts (e.g., tartrate vs. succinate) or release mechanisms (immediate vs. extended) are NOT therapeutically equivalent.
- Metoprolol tartrate is immediate-release; metoprolol succinate is extended-release.
- Not interchangeable without prescriber's order.
- Substitution requires pharmacist/prescriber approval and documentation.
Memory trick: Discrepancy found, stop and ask the pharmacist around.