Amlodipine(10 mg) anddiltiazem(30 mg) are bothcalcium channel blockers (CCBs)used to treat hypertension and angina.

When a patient is prescribed two medications from the same therapeutic class, the pharmacy's prescription processing system may flag this as"therapeutic duplication."

This alert is meant toprevent potential adverse effectssuch as excessive lowering of blood pressure or heart rate.

A. Prior authorization required→ Not applicable unless the insurance requires special approval before covering the drug.

C. NDC not covered→ Would appear if the specific drug product (based on its National Drug Code) is not covered by insurance, but this scenario relates to duplication, not coverage.

D. Refill too soon→ This applies to refilling a medication before the allowed time frame, but the scenario describes a new prescription.

PTCB PTCE Exam Content Outline – Drug Interactions and Therapeutic Duplication

Lexicomp and Micromedex Drug Databases– Reference sources for drug classifications.

ISMP Guidelines on Preventing Therapeutic Duplication Errors

Why Other Answers Are Incorrect?Pharmacy Technician References: