Pharmacy Division Ramathibodi Hospital


News 04/08/2544

Community pharmacists are in a unique position to decrease negative medication outcomes in ambulatory patients.

The use of antipsychotic drugs appears to be a risk factor for venous thrombosis.

Medication Errors
The Role of the Community Pharmacist in Identifying, Preventing, and Resolving Drug-Related Problems

Jennifer Cerulli, PharmD, BCPS


It is estimated that 3% to 10% of hospital admissions are a consequence of drug-related morbidity and mortality, and half of those admissions are preventable.[1] In 1995, the direct annual cost spent on preventable drug-related morbidity and mortality in the US ambulatory population was estimated to be $76.6 billion dollars[2]; in 2000, the amount exceeded $177.4 billion.[3] These preventable negative patient outcomes and their associated costs have caught the attention of patients, healthcare professionals, and governmental agencies.[4]

Drug-related morbidity and mortality often are preceded by a drug-related problem.[5] Drug-related problems have been defined as events or circumstances involving a patient's drug treatment that actually, or potentially, interfere with the achievement of an optimal outcome.[6] Most drug-related problems can be assigned to 1 of 8 categories, listed in Table 1.[6-8]

Pharmacists in all practice settings have been encouraged to provide pharmaceutical care to identify, prevent, and resolve drug-related problems and reduce negative medication outcomes. Pharmaceutical care has been defined as the responsible provision of drug therapy for the purpose of achieving defined outcomes that improve a patient's quality of life.[5] A patient-centered, outcomes-oriented practice requires the pharmacist to work in concert with the patient's healthcare team to promote health, prevent disease, and assess, monitor, initiate, and modify medication use to ensure that drug-therapy regimens are safe and effective.[9] The American Pharmaceutical Association has defined the steps that pharmacists should take to provide pharmaceutical care in any setting (Table 2).[9]

Studies have shown that pharmacists can reduce medication errors, improve patient outcomes, and decrease costs by providing patient-care services in a variety of settings.[10] Community pharmacists are in a unique position to decrease negative medication outcomes in ambulatory patients. In this setting, pharmacists are readily accessible to their patients and often have existing relationships that can be built on to provide further care.

Community Pharmacy Practice

For decades, pharmacists in the community setting have performed an invaluable service for patients and their communities by avoiding medication-related problems with the use of a drug utilization review and patient counseling. Although these services were regarded as essential, they often were not documented. As the profession began to emphasize pharmaceutical care and define the role of the pharmacist, it was recognized that there was a paucity of data documenting the community pharmacist's role in ensuring safe medication use.

Rupp and colleagues[11,12] conducted a series of studies on prescription-related problems and interventions by community pharmacists. Subsequent publications estimated the direct costs avoided because of pharmacist intervention.[13,14] Trained observers (senior pharmacy students on community pharmacy clerkships) documented pharmacist interventions on new prescriptions. A standard evaluation form was used to document and characterize interventions as errors of omission, errors of commission, drug interactions, or other.

Errors of omission occurred when information essential to filling the prescription was missing (ie, drug, dose, or dosage form not specified on the prescription). Because the prescription could not be filled until clarified, those errors were thought to incur minimal risk to the patient. Errors of commission consisted of the prescriber incorrectly specifying the dosage regimen or strength of the prescription or the occurrence of therapeutic duplication. Because the prescription could be filled, those errors could harm the patient.

The first series of observations involved 9 community pharmacies filling 5874 new prescriptions.[11] Of those, 2.6% (153) required active intervention by the pharmacist. Approximately one half (51%) of the errors were errors of omission and 29% were errors of commission. A subsequent study used 2 experts in pharmacotherapeutics to evaluate the clinical significance of the prescribing errors and interventions.[13] The expert panel concurred that 38 of the documented errors would have resulted in harm to the patient had the pharmacist not intervened. The estimated direct medical costs avoided (prescriber office visits, emergency-department visits, and hospitalizations) for all 153 interventions was $7.15 per intervention. Although the average time for each intervention was not documented, the investigator assumed an average intervention time of 7 minutes, for a cost of $1.75 (based on $15 per hour) for the pharmacist to intervene. Thus, the cost of intervening was lower than the direct medical costs avoided.

The investigators repeated this study with a larger sample of 89 community pharmacies located in 5 states.[12] Of the 33,011 new prescriptions screened, 1.9% required pharmacist intervention. Forty-six percent of the documented prescription problems involved errors of omission, and 36% resulted from errors of commission. A panel of 3 experts reviewed the interventions and concurred that 28.3% (n = 176) of the identified errors could have resulted in harm to the patient if the problem had not been corrected by a pharmacist. The estimated direct costs of medical care avoided were $123.00 per problematic prescription and $2.32 for each new prescription order screened during the study.[14] Pharmacist intervention rate was negatively correlated with the hourly prescription volume (r = -.40, P < .001). Although that study was conducted in 1990, when advanced dispensing technology was not available, it does cause some concern in light of the ever-increasing prescription volume and shortage of pharmacists.

In a separate study, pharmacists in 4 community pharmacies documented their interventions for 6000 prescription orders received.[15] Each pharmacy dispensed an average of fewer than 100 prescriptions per day. Investigators provided pharmacists with videotape training and a 15- to 20-minute individual orientation on how to complete the pharmacist intervention form. Participating pharmacists were provided with $50.00 compensation to participate; however, 2 pharmacies declined compensation. Forty-seven interventions were documented, representing 0.78% of the 6000 new prescription orders presented to the pharmacy. The errors of omission accounted for 43.3% of interventions, and errors of commission accounted for 23.4%. Forty-seven percent of the interventions could have resulted in harm to the patient. Two evaluators estimated the value of the interventions to be approximately $3.50 per prescription processed. The intervention rate in that study was lower than those in previous studies, perhaps because of the reliance on pharmacist documentation rather than trained observers. That finding shows the potential barrier of pharmacists providing documentation, even with low prescription volumes.

Those studies described pharmacist interventions and the provision of standard pharmacy care. Investigators then examined the ability of a patient-oriented pharmacist to provide pharmaceutical care in the community setting.[16] Pharmacists were provided with a 40-hour education program designed to develop the participants' problem-solving and communication skills. Investigators also restructured the independent community pharmacy. Patients were randomized to an intervention group or control group. The intervention consisted of the pharmacist completing an interview and patient history. The control group received standard counseling. Pharmacists documented the number and types of interventions that occurred over 6 months. Interventions were categorized as prescription-related (errors of omission or commission) or drug-related problems.

Of the 91 patients originally randomized to the intervention group, 21% had drug-related problems detected. Of the 905 control patients, 2.9% had problems identified, mainly prescription-related problems. Patients in the intervention group were 9 times more likely to have a problem identified (odds ratio = 8.9, 95% confidence interval = 4.7-16.9). The period spent counseling patients was similar in each group (approximately 2 minutes). In the intervention group, the average time spent with patients was 27 minutes, with the majority of time spent during the initial interview and documentation. Outcome assessment and cost analyses were not conducted. Educational training and completion of patient histories resulted not only in the increased intervention rate but also took the interventions beyond prescription-related errors (errors of commission or omission) toward patient-specific drug-related problems.

Obstacles to Pharmaceutical Care

There are several obstacles to the provision of pharmaceutical care in the community pharmacy.[8] One important obstacle is the time required to provide care and the lack of reimbursement for that time. As community pharmacists across the country struggle to obtain compensation for the provision of cognitive services, several states have made great progress in providing that compensation. The Wisconsin Medicaid Program Incentive-Based Pharmacy Payment System began in July 1996 to reimburse pharmacists for cognitive services by using a complexity-adjusted fee.[17] When the pharmacy bills for pharmaceutical care services that provide an enhanced fee, the dispensing fee is waived. The fee schedule is based on the level of service (time spent) and the reason, action, and result codes. In the first 14 months of the pilot program, 170 pharmacy providers delivered 1158 pharmaceutical-care services to 1271 patients. After that demonstration project, several managed-care insurers adopted the state's plan for their enrollees.

In April 1998, Mississippi became the first state to pay pharmacists to provide disease management for Medicaid patients as a result of a waiver granted from the Health Care Financing Administration.[18] Under that plan, appropriately credentialed pharmacists are reimbursed $20 for each 15- to 30-minute session with patients diagnosed with asthma, diabetes mellitus, hyperlipidemia, or coagulation disorders. Pharmacists managing patients referred by their physicians with the use of established protocols must keep records and provide a private consultation area. Other states and pharmacy organizations considering the implementation of similar programs are closely watching the Wisconsin and Mississippi programs. Some difficulties encountered in these programs were defining the credentialing process, developing and maintaining appropriate documentation, and educating eligible patients about the availability of the demonstration programs and the benefits of receiving pharmaceutical care.[19] Patient factors that inhibited communication and participation in the programs were the lack of telephones, permanent addresses, or transportation.

Those studies described the impact of the community pharmacist detecting and avoiding prescription errors or drug-related problems. A discussion of the role of the pharmacist in the medication-use process also must include avoiding medication errors during the dispensing process. With the explosion of new medications, an increase in prescription volume, and the expansion of the use of technology and technicians in the dispensing process, it is essential that pharmacists evaluate their dispensing processes to reduce the potential for error. The Institute for Safe Medication Practices (ISMP), a nonprofit organization, has developed the Medication Safety Self-Assessment tool for Community/Ambulatory Pharmacy.[20] The tool has the 10 domains that most significantly influence safe medication use. The tool focuses on the entire medication-use process, including communication of prescriptions, drug labeling and packaging, drug storage and distribution, and patient monitoring. The tool contains more than 190 self-assessment characteristics a pharmacy can use to assess the safety of its medication-use process and identify areas for improvement. Pharmacies will be able to enter their data confidentially into the ISMP Web site to receive a report that can be used to make improvements and compare themselves to similar pharmacies. The tool is currently undergoing beta testing in 40 pharmacies and will be available on the ISMP Web site.


Community pharmacists remain an essential component of the medication-use process in the ambulatory setting. Each day pharmacists avoid errors of omission and commission during the drug utilization review. By communicating with the patient and providing expanded services, pharmacists can detect patient-specific drug-related problems to reduce the risk of medication-related morbidity and mortality. Community pharmacies currently struggle with balancing the increased prescription volume and staffing shortages with their desire to provide comprehensive pharmaceutical care. The increased use of technology and work-flow improvements and compensation for cognitive services can increase the provision of pharmaceutical care to ambulatory patients. Although obstacles to providing pharmaceutical care in the community setting exist, pharmacists are demonstrating the ability to overcome those obstacles to improve the medication-use process.

Table 1. Drug-Related Problems[6-8]

Unnecessary drug therapy (drug without indication)
Untreated indication (indication without drug)
Improper drug selection
Subtherapeutic dosage
Adverse drug reaction
Drug interaction
Failure to receive drug (inappropriate compliance)

Table 2. Steps to Provide Pharmaceutical Care[9]

1. Establish and maintain professional relationships
2. Collect, organize, record, and maintain patient-specific information
3. Evaluate information to identify, prevent, and resolve drug-related problems
4. Develop drug-therapy plan mutually with the patient
5. Implement drug-therapy plan and ensure that the patient has the supplies, information, and knowledge necessary to carry out the plan
6. Review, monitor, and modify the drug-therapy plan


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  4. Kohn LT, Corrigan JM, Donaldson MS, eds. Institute of Medicine Report: To Err Is Human: Building a Safer Health System. Washington, DC: National Academy Press; 1999. Available at err is human/
  5. Hepler CD, Strand LM. Opportunities and responsibilities in pharmaceutical care. Am J Hosp Pharm. 1990;47:533-543.
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  9. American Pharmaceutical Association. Principles of Practice for Pharmaceutical Care. Available at:
  10. Schumock GT, Meek PD, Ploetz PA, et al. Economic evaluations of clinical pharmacy services -- 1988-1995. The Publications Committee of the American College of Clinical Pharmacy. Pharmacotherapy. 1996;16:1188-1208.
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  12. Rupp MT, DeYoung M, Schondelmeyer SW. Prescribing problems and pharmacist interventions in community practice. Med Care. 1992;30:926-940.
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  15. Dobie RL, Rascati KL. Documenting the value of pharmacist interventions. Am Pharm. 1994;NS34:50-54.
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  17. HMOs adopt Wisconsin Medicaid pilot project for commercial enrollees. Payment Strat Pharmaceut Care. 1998;3:1,2,5-8.
  18. Medicaid to pay Mississippi pharmacists for disease management. Am J Health Syst Pharm. 1998;55:1238-1239.
  19. Pharmacists tackle outreach issued in Medicaid-based reimbursement demonstration program. Payment Strat Pharmaceut Care. 1998;3:1-3.
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Antipsychotic Drug Use Linked to Venous Thrombosis

LONDON (Reuters Health) Jul 27 - The use of antipsychotic drugs appears to be a risk factor for venous thrombosis, according to a report published in the July issue of the British Journal of Psychiatry.

Dr. Jan P. Vandenbroucke and colleagues, from Leiden University Medical Center in the Netherlands, reviewed autopsy reports on 10 psychiatric patients who died of idiopathic pulmonary emboli, performed a brief literature review of venous thrombosis in psychiatric patients, and re-analyzed data from a case-control study on patients with deep vein thromboses (DVTs).

Antipsychotic drug use was confirmed in five of the 10 autopsied patients, the researchers state. Several German studies, identified in the literature review, found a higher incidence of venous thrombosis in psychiatric patients after the introduction of chlorpromazine and its analogues. Re-analysis of the case-control study revealed that none of the 474 control subjects used antipsychotics compared with four of the 474 patients with DVTs.

"When a patient uses antipsychotic drugs in the presence of risk factors for venous thrombo-embolism, the attending physician should be aware of the increased risk of venous thrombosis," Dr. Vandenbroucke's team emphasizes.

The authors believe that "the association between venous thrombosis and antipsychotic medication should be studied in investigations specifically designed to elucidate mechanisms by which the use of antipsychotics leads to venous thrombosis."

Br J Psychiatry 2001;179:63-66.

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