PTCB Certified Pharmacy Technician (PTCE)MedicationsMedium
A patient calls the pharmacy asking about a new prescription for 'metoprolol succinate extended-release.' They previously took 'metoprolol tartrate.' The patient wants to know if they are the same medication. What is the most appropriate response from the pharmacy technician?
- AThey are interchangeable once you adjust the dosage, but you should confirm with the pharmacist.
- BYes, they are the exact same medication, just different brand names.
- CThey are both metoprolol, but they have different salts and release mechanisms. You should speak with the pharmacist or your prescriber.
- DNo, they are completely different medications and should not be interchanged.
Show answer & explanationAnswer & explanation
Correct answer: C. They are both metoprolol, but they have different salts and release mechanisms. You should speak with the pharmacist or your prescriber.
Metoprolol succinate and metoprolol tartrate are different salts of the same active drug, metoprolol. They have different pharmacokinetic properties (e.g., immediate vs. extended release) and are not therapeutically equivalent or interchangeable without a prescriber's order.
Why the other options are wrong
- A. Incorrect. Dosage adjustment alone does not make them interchangeable; a prescriber's order is required.
- B. Incorrect. While the active ingredient is similar, the salts and release mechanisms differ significantly.
- D. Incorrect. They share the same active drug, metoprolol, but are not interchangeable.
Therapeutic Equivalence
Medications that contain the same active ingredient, have the same dosage form and strength, and are bioequivalent, thus having the same clinical effect and safety profile.
- Determined by the FDA (e.g., 'Orange Book').
- Generic substitutes must be therapeutically equivalent to their brand-name counterparts.
- Different salts or release mechanisms of the same drug may not be therapeutically equivalent.
Memory trick: Same Drug, Same Dose, Same Effect? Check the Orange Book for the Best.