Historical Context & Legislative Motivation
The concept of Drug Utilization Review (DUR) arose from a growing recognition in the latter half of the twentieth century that medication errors, adverse drug events, and inappropriate prescribing patterns were imposing enormous human and economic costs on the healthcare system. Prior to formal DUR mandates, pharmacists filled prescriptions largely as technical dispensers, with limited legal expectation to evaluate the clinical appropriateness of each order. A series of high-profile adverse drug events, coupled with rising Medicaid expenditures on pharmaceuticals, prompted both federal and state legislatures to codify DUR as a pharmacist's legal responsibility. The evolution from voluntary clinical screening to a legally mandated, documented process reflects a broader shift in pharmacy practice—from product-oriented dispensing to patient-centered pharmaceutical care.
The central question OBRA '90 and subsequent state laws sought to answer was straightforward yet profound: how can the healthcare system ensure that every prescription dispensed is therapeutically appropriate, safe, and consistent with the patient's overall medication regimen? Drug utilization review became the answer—a legally mandated checkpoint that positions the pharmacist as the last clinical safeguard before a medication reaches the patient.
Core Principles & Definitions
Drug utilization review is a structured, ongoing evaluation of prescribing, dispensing, and patient use patterns to promote optimal medication therapy. Federal and state law recognize three temporal categories of DUR, each serving a distinct function within the medication use process. Understanding these categories—and the specific screening parameters within each—is essential for MPJE preparation and competent pharmacy practice.
Prospective DUR (ProDUR)
Concurrent DUR
Retrospective DUR (RetroDUR)
OBRA '90 Screening Parameters
Documentation Requirement
Visual Explanation — The Prospective DUR Workflow
The diagram above illustrates the complete prospective DUR workflow that must occur before every prescription is dispensed. Notice that the process is not a simple pass/fail gate—it requires the pharmacist to first access and review the patient's medication profile, then systematically evaluate six categories of potential problems. When the pharmacist identifies a clinically significant issue, the prescription is held while the pharmacist contacts the prescriber or counsels the patient. Crucially, both pathways—whether an issue was found or not—terminate in a documentation step. Many pharmacists mistakenly believe that documentation is only required when a problem is detected; in reality, the absence of problems should also be recorded to demonstrate that the review was actually performed.
The DUR Mechanism — OBRA '90 Screening Parameters in Depth
OBRA '90 established six minimum screening parameters that pharmacists must evaluate during prospective DUR. While individual state pharmacy practice acts may expand these requirements, no state may set standards below the federal floor. Understanding each parameter in clinical and legal context is essential for the MPJE, which frequently tests the pharmacist's ability to identify which parameter applies to a given clinical scenario.
The Six OBRA '90 Screening Parameters
| Parameter | Definition | Clinical Example |
|---|---|---|
| Therapeutic Duplication | Two or more drugs from the same pharmacologic class prescribed concurrently without clinical justification | Patient receiving both lisinopril and enalapril (two ACE inhibitors) |
| Drug-Disease Contraindication | A prescribed drug is contraindicated by the patient's existing medical condition | NSAID prescribed for a patient with active peptic ulcer disease |
| Drug-Drug Interaction | Two or more drugs that interact pharmacokinetically or pharmacodynamically to cause adverse effects or reduced efficacy | Warfarin prescribed concurrently with fluconazole (CYP2C9 inhibition increases bleeding risk) |
| Incorrect Drug Dosage or Duration | Dose too high, too low, or therapy duration inappropriate for the indication, age, weight, or renal/hepatic function | Metformin 2000 mg prescribed for a patient with eGFR < 30 mL/min |
| Drug-Allergy Interaction | A prescribed drug belongs to a class or contains a component to which the patient has a documented allergy | Amoxicillin prescribed for a patient with documented penicillin anaphylaxis |
| Clinical Abuse or Misuse | Patterns suggesting the patient is obtaining excessive quantities, using medications inappropriately, or showing signs of substance abuse | Patient obtaining oxycodone from three different prescribers within 30 days (doctor shopping) |
Pharmacists should note that OBRA '90 also requires the maintenance of patient medication records as a prerequisite for effective DUR. Without a comprehensive, up-to-date patient profile—including current medications, known allergies, relevant disease states, and demographic information such as age and pregnancy status—the pharmacist cannot meaningfully perform the mandated screening checks. The patient profile serves as the clinical data substrate upon which every DUR evaluation depends, and state laws universally require pharmacists to make a reasonable effort to obtain this information.
Documentation Standards & DUR Board Structure
Performing the DUR check is only half of the pharmacist's legal obligation; the other half is documenting outcomes. Documentation creates a defensible record that the review occurred, captures the clinical reasoning behind any intervention, and provides data for retrospective analysis. OBRA '90 requires each state to establish a DUR Board composed of physicians and pharmacists who develop standards, review retrospective data, and issue educational interventions. The DUR Board relies on the documentation pharmacists create at the point of dispensing to identify system-wide prescribing trends and target improvement efforts.
Essential Documentation Elements
- Date and time the DUR was performed
- Identity of the pharmacist who conducted the review
- Nature of the problem detected (or explicit notation that no problem was found)
- Action taken: prescriber contacted, prescription modified, prescription held, or patient counseled
- Resolution: prescriber's response, new order if applicable, or patient's acknowledgment if the prescriber confirmed the original order
- Override justification: if a DUR alert is overridden, the clinical rationale must be recorded
Worked Example — A Complete DUR Encounter
The following worked example walks through a realistic clinical scenario that a community pharmacist might encounter, illustrating each step of the prospective DUR process and the corresponding documentation requirements.
Strengths & Limitations of Current DUR Systems
While DUR has demonstrably improved medication safety since OBRA '90, the system is not without its limitations. Modern pharmacy practice contends with a phenomenon known as alert fatigue—the tendency for pharmacists to become desensitized to DUR alerts because automated systems generate an overwhelming volume of clinically insignificant warnings. Research suggests that pharmacists override 70–90% of automated DUR alerts, raising serious questions about the effectiveness of current clinical decision support tools.
| Strengths | Limitations |
|---|---|
| Legally mandates a systematic safety review for every prescription, creating a consistent standard of care | Alert fatigue: high override rates (70–90%) may cause pharmacists to dismiss genuinely significant alerts |
| Positions the pharmacist as a clinical professional, not merely a dispenser, enhancing the profession's patient care role | Incomplete patient profiles: patients using multiple pharmacies or obtaining OTC medications may have fragmented records |
| Creates documentation that protects pharmacists in malpractice litigation by demonstrating due diligence | Workflow burden: documentation requirements add time to each dispensing event, particularly in high-volume settings |
| Retrospective DUR generates population-level data that can reveal prescribing trends and improve public health outcomes | Variability across states: differing requirements complicate compliance for multistate pharmacies and pharmacists |
| Integrates with PDMP data to help identify controlled substance misuse and diversion patterns | Software limitations: some systems lack nuanced clinical context, flagging interactions of minimal clinical significance |
Connection to Advanced Concepts — MTM, CDTM, & Evolving DUR
Drug utilization review represents the foundational layer of pharmacist-driven clinical services. As pharmacy practice evolves, DUR principles are being extended into more comprehensive frameworks such as Medication Therapy Management (MTM) and Collaborative Drug Therapy Management (CDTM). Understanding how DUR relates to these advanced clinical services provides important context for MPJE preparation, since many state laws now authorize pharmacists to exercise broader prescriptive authority contingent on maintaining robust DUR documentation.
| Feature | Traditional DUR (OBRA '90) | MTM / CDTM (Advanced Practice) |
|---|---|---|
| Scope | Per-prescription safety screening (reactive) | Comprehensive medication therapy review (proactive); may include initiating, modifying, or discontinuing therapy |
| Legal Authority | Federal mandate (OBRA '90) plus state pharmacy practice acts | State-specific collaborative practice agreements or statutory CDTM authority; Medicare Part D MTM requirements |
| Documentation | DUR alert logs, override justifications, intervention records | Comprehensive medication action plans, personal medication records, SOAP notes, and outcome tracking |
| Patient Interaction | Primarily at the point of dispensing; brief counseling | Extended consultations; ongoing monitoring; shared decision-making with patient and prescriber |
| Reimbursement | Embedded in dispensing fee; no separate billing | Separately billable cognitive services under CPT codes; Medicare Part D MTM reimbursement |
Looking ahead, pharmacy practice is moving toward integrating DUR data with Prescription Drug Monitoring Programs (PDMPs), electronic prescribing networks, and interoperable health information exchanges. Many states now require pharmacists to consult the PDMP before dispensing controlled substances—effectively adding a seventh screening parameter to the traditional DUR framework. Additionally, emerging concepts like pharmacogenomic screening may eventually become part of the standard DUR process, allowing pharmacists to identify patients who are poor metabolizers of specific drug substrates before dispensing. The MPJE increasingly tests candidates on their understanding of these evolving expectations, making it essential to understand DUR not as a static regulatory requirement but as a dynamic, expanding professional responsibility.
Practice Problems
Lesson Summary
Drug Utilization Review (DUR) is a federally mandated, legally required process that pharmacists must perform before dispensing every prescription. Established by OBRA '90 and implemented through state pharmacy practice acts, DUR encompasses three temporal categories: prospective (before dispensing), concurrent (during therapy), and retrospective (after dispensing). The six minimum screening parameters—therapeutic duplication, drug-disease contraindications, drug-drug interactions, incorrect dosage or duration, drug-allergy interactions, and clinical abuse or misuse—form the federal floor that no state may fall below, though many states add additional requirements.
Equally important to performing the DUR is documenting the outcome—whether a problem was found or not—including the nature of any issue, the action taken, prescriber communication, and the final resolution. Documentation feeds into the state DUR Board's retrospective analysis and creates a defensible legal record of the pharmacist's clinical judgment. Modern challenges include alert fatigue and incomplete patient profiles, while the evolving landscape of MTM, CDTM, PDMPs, and pharmacogenomics continues to expand the pharmacist's DUR responsibilities beyond the original OBRA '90 framework.