Therapeutic Duplication as a Medication Safety Risk

Introduction

Therapeutic duplication refers to a situation in which a patient is prescribed two or more drugs from the same class, or with similar clinical effects, for the same condition without a clearly stated reason, sequencing plan, or instruction set (Huynh & Rajendran, 2021). This issue is important because unnecessary overlap in therapy can expose patients to avoidable adverse events, excessive dosing, toxic effects, and meaningful drug interactions that compromise safe care (Bocknek et al., 2022).

Examples in Practice

Examples of therapeutic duplication include prescribing acetaminophen and ibuprofen for pain without specifying the intended sequence of use, ordering two nonsteroidal anti-inflammatory drugs such as ibuprofen and naproxen, placing multiple antiemetic orders for the same symptom without clear sequencing, prescribing antihypertensive agents from the same class without a clear rationale, and unintentionally overlapping anticoagulants during medication transitions (Huynh & Rajendran, 2021). 

Causes and Contributing Factors

Duplicate therapy commonly arises when care is spread across multiple clinicians and medication information is not reconciled completely during handoffs or transitions (Bocknek et al., 2022). The problem may also stem from confusion between generic and brand names, especially when the same medication appears under different names across records. Within electronic prescribing systems, risk increases when earlier orders remain active or when the record does not make the intended order of first-line and second-line treatments easy to understand (Dawson et al., 2023).

Intended Versus Unintended Duplication

Not every instance of overlapping therapy is inappropriate. In some situations, concurrent medications are prescribed intentionally as part of multimodal treatment or a planned sequence of care. However, when the reason for overlap is not explicitly documented, clinicians, pharmacists, and nurses may have difficulty distinguishing an intentional treatment plan from a prescribing error, thereby increasing the risk of patient harm.

Prevention Strategies

Reducing therapeutic duplication requires more than individual vigilance; it depends on coordinated safety practices across the care continuum. Effective measures include thorough medication reconciliation at every key transition point, pharmacist review of active orders, clear indication of whether a therapy is intended as first-line or backup treatment, and electronic decision support to help identify potential duplicate orders before harm occurs (Dawson et al., 2023; Huynh & Rajendran, 2021). Reliable communication among prescribers, pharmacists, and nursing staff is equally important in preventing avoidable duplication and improving medication safety overall (Bocknek et al., 2022).

Additional Safeguards

Further protection against duplicate therapy comes from keeping a single, up-to-date medication list across settings, checking both generic and brand names during each review, promptly discontinuing outdated orders in the health record, and expecting prescribers to explain why same-class medications are being used together when that occurs (Bocknek et al., 2022; Dawson et al., 2023). Additional support can come from standardized order sets that separate first-choice and second-choice as-needed medications, pharmacist review of high-risk categories such as opioids and anticoagulants, and patient education that encourages individuals to bring all medications or an accurate medication list to appointments (Dawson et al., 2023; Huynh & Rajendran, 2021).

Organizational Responsibilities

Organizations also play a central role in preventing therapeutic duplication. Health systems can improve performance by tracking duplicate-order events, examining near misses, standardizing medication-use expectations for higher-risk drug classes, and offering focused education for prescribers and nurses. It is also important to refine electronic health record alerts so they are specific enough to identify meaningful duplication without overwhelming clinicians with excessive warnings (Bocknek et al., 2022; Dawson et al., 2023). When these efforts are sustained, they strengthen accountability across disciplines and contribute to a safer medication-use culture.

Case Evidence

Case literature illustrates how serious duplicate therapy can become when it goes unrecognized. One published example described a patient discharged on both warfarin and rivaroxaban for recurrent pulmonary embolism, leading to a dangerously elevated international normalized ratio (INR > 8.0) and a substantial risk of major bleeding before the error was detected (Fusco et al., 2015). Other analyses have reported duplicate-therapy problems in outpatient and retail settings, including combined dispensing of an angiotensin-converting enzyme inhibitor with sacubitril/valsartan and conflicting duplicate antihypertensive regimens. When discrepancies like these are not corrected quickly, patients may face renal injury, poor blood pressure control, and other preventable complications (Punatar et al., 2023). These cases make clear that therapeutic duplication is a clinical safety issue with potentially severe consequences, not simply a documentation concern.

Summary

Therapeutic duplication is a preventable prescribing problem that occurs when patients receive medications with overlapping purposes, and the reason for that overlap is not clearly documented. In practice, these errors are often tied to weak communication, incomplete medication review, and electronic ordering processes that do not fully support clear treatment sequencing. The consequences can include drug interactions, toxicity, unnecessary duplication of effect, and serious patient harm.  The most effective safeguards include accurate medication reconciliation, explicit documentation of prescribing intent, pharmacist participation in order review, and ongoing organizational efforts to strengthen safe medication-use systems.

References

Bocknek, L. S., Kim, T. C., Spaar, P. A., Russell, J. L., Busog, D.-N. C., Howe, J. L., Boxley, C. L., Ratwani, R. M., Krevat, S., Jones, R., & Franklin, E. S. (2022). Duplicate medication order errors: Safety gaps and recommendations for improvement. Patient Safety, 4(3), 39–47. https://doi.org/10.33940/data/2022.9.6

Dawson, T. E., Beus, J., Orenstein, E. W., Umontuen, U., McNeill, D., & Kandaswamy, S. (2023). Reducing therapeutic duplication in inpatient medication orders. Applied Clinical Informatics, 14(3), 538–543. https://doi.org/10.1055/a-2082-4631

Huynh, I., & Rajendran, T. (2021). Therapeutic duplication on the general surgical wards. BMJ Open Quality, 10(3), e001363. https://doi.org/10.1136/bmjoq-2021-001363

Fusco, J. A., Paulus, E. J., Shubat, A. R., & Miah, S. (2015). Warfarin and rivaroxaban duplication: A case report and medication error analysis. Drug Safety – Case Reports, 2(1), 5. https://doi.org/10.1007/s40800-015-0007-3

Punatar, N., Molla, M., & Lee, S. (2023, March 15). Duplicate therapies in retail pharmacy. 

PSNet, Agency for Healthcare Research and Quality. https://psnet.ahrq.gov/web-mm/duplicate-therapies-retail-pharmacy