Linda M. Strand

Drug-related problems : their structure and function

In order to better focus the role of the pharmacist on patient need and patient outcome, a means of categorizing drug-related problems (DRPs) is presented. A DRP exists when a patient experiences or is likely to experience either a disease or symptom having an actual or suspected relationship with drug therapy. Eight different categories of DRPs are described and examples of each category are offered. This categorization serves a number of functions, such as: (1) to illustrate how adverse drug reactions form but one category of extant DRPs, (2) to make tangible the pharmacists role for the future, (3) to serve as a focus for developing a systematic process whereby the pharmacist contributes significantly to the overall positive outcome of patients, (4) to bring to pharmacy practice a vocabulary consistent with that of other healthcare professionals, and (5) to aid in the development of standards of practice for pharmacists.

The Impact of Pharmaceutical Care Practice on the Practitioner and the Patient in the Ambulatory Practice Setting: Twenty-five Years of Experience

This manuscript reviews 25 years of experience that include developing the practice of pharmaceutical care and initiating new practices. The impact this practice has on practitioners in the ambulatory setting is described as well as data that reflect its clinical and economic impact. There is a great need to prepare new practitioners to provide pharmaceutical care. A focused training program was developed and delivered to over 300 practitioners. The practitioners were prepared by providing direct patient care. They learned the philosophy of pharmaceutical care practice, to identify, resolve and prevent drug therapy problems, to document care using a specially designed software program called the Assurance Pharmaceutical Care program. The practitioners who participated in the training program reported that the average amount of time spent with patients increased three-fold, they now see four times more patients than prior to training, and the number of new patients referred by physicians increased nine-fold as a result of the program. These practitioners have now provided care to more than 25,000 patients in their practices. These data have now been consolidated and analyzed, and a portion of these results is reported here. The clinical and economic outcomes from 2,985 adult patients, who received pharmaceutical care between January, 2000 and December, 2003, are presented. At the first assessment by the pharmaceutical care practitioner, 61% of the patients had one or more drug therapy problems identified and resolved. This resulted in an improvement in the clinical status or maintaining a stable status in 83% of the patients. The health care savings realized from pharmaceutical care were

Heparin‐induced thrombocytopenia in patients with cerebrovascular ischemic disease

1,134,162. This represented a benefit to cost ratio of 2:1. Physicians who collaborate with pharmaceutical care practitioners have validated the work of the practitioners, and patients are recognizing the benefits of pharmaceutical care.

Practice Functions Necessary for the Delivery of Pharmaceutical Care

We studied 137 patients who were treated with heparin for cerebral infarction (73), partially reversible ischemic neurologic deficit (22), or transient ischemic attack (42). Platelet counts were performed before therapy, twice weekly, and at cessation of therapy. Platelets decreased in 118 patients (86%). In 21 (15.3%), platelets dropped ≥40%; 9 of 14 new ischemic events and three of six deaths occurred in this group of patients. Because there was a significant association between poor outcome and platelet drop ≥40% (p < 0.001), we believe that platelets should be monitored frequently when patients are treated with heparin for ischemic cerebrovascular disease.

Saliva-serum theophylline concentrations: Substantial intrapatient and interpatient variation in predicting serum concentrations

Pharmaceutical care is a concept outlining the responsibilities of individual pharmacists to individual patients. Although widely accepted on a philosophical basis, there is a lack of comprehensive information about the functions and responsibilities pharmacists undertake when providing pharmaceutical care. Pharmacy educators and practitioners at the faculty of pharmacy, University of Toronto, developed and informally tested a process that details the practice functions required of pharmacists when providing pharmaceutical care as originally defined.

Consistent standards in medication use: the need to care for patients from research to practice.

The relationships between serum and saliva concentrations were evaluated in 18 patients after single doses of three theophylline preparations. Simultaneous multiple saliva and serum samples were obtained after theophylline ingestion and were analyzed for theophylline content by the modified Schack and Waxier spectrophotometric method. Significant variability was observed in the data for those saliva/serum ratio sets obtained within 30 min of dosage. The mean correlation coefficient for saliva/serum sample sets obtained at and after 30 min was 0.86. Pearson product moment correlation coefficients determined for saliva/serum ratios at 2,4,6, and 8 hr ranged from 0.84 to 0.89, leaving 26% of the variance unexplained. Serum concentrations were calculated from a randomly selected saliva/serum ratio for each patient. Predicted serum concentrations were ± 2 μg/ml of measured concentrations in only 143 of the 196 determinations (73%). Therefore, the use of saliva concentrations to predict serum values has substantial error in specific patients and may lead to incorrect dosage adjustments.

Determination of theophylline bioavailability using saliva theophylline concentrations

OBJECTIVE To propose adoption of practice standards for pharmacists based on the principles of pharmaceutical care that are parallel to internationally accepted ethical precepts governing clinical research. DATA SOURCES Relevant literature selected by the authors. SUMMARY Pharmaceutical care practice standards can create a continuum of high quality care for patients from research through practice and are presented as a rational solution to managing the benefits and risks of medication use. By implementing these practice standards, patients are empowered to become active participants in the treatment process, knowledge of drug effectiveness and safety is increased, and the pharmaceutical care practitioners responsibilities are delineated. More than a quarter century ago, the research community adopted the ethical principles of respect for persons, beneficence, and justice, as outlined in the Belmont Report: Ethical Principles and Guidelines for the Protection of Human Subjects of Research. Under these guidelines, research subjects are considered participants, knowledge of medication efficacy and safety has increased, and investigator responsibilities have been defined. However, these guidelines only apply to the life cycle of a drug before approval by the Food and Drug Administration. Once the product is released for general use, fewer standards are applied. Pharmacy has the opportunity to establish parallel standards for the clinical use of medications in patients by establishing patient care practices in consonance with pharmaceutical care practice. CONCLUSION Pharmaceutical care practitioners need to apply new practice standards that allow them to contribute meaningfully to appropriate, effective, safe, and convenient drug therapy for all patients. Such pharmaceutical care practice standards could ensure consistent vigilance throughout the life cycle of the drug product and result in rational, appropriate, effective, safe, and convenient drug therapy for all patients.

Observed differences in gentamicin pharmacokinetic parameters and dosage recommendations determined by fluorescent polarization immunoassay and radioimmunoassay methods

Substantial error occurs when individual saliva theophylline concentrations are used to predict serum theophylline concentrations. However, the use of saliva theophylline concentrations to determine product bioavailability has never been evaluated. Subjects in this study were 18 stable patients (20–51 yr) with a history of chronic obstructive pulmonary disease. Three preparations — a capsule (Elixophyllin 400 mg), elixir (Elixophyllin 373 mg), and tablet (Theolair 375 mg) — were administered in a randomized crossover design. Serum and saliva samples were obtained pre‐dose and 0.25, 0.5, 1, 2, 4, 6, and 8 hours after theophylline administration. The saliva AUC0–∞ and serum AUC0–∞ were highly associated for the elixir (r = 0.84) tablet (r = 0.89), and capsule (r = 0.89). The bioavailability of the tablet and capsule calculated from elixir saliva and elixir serum AUC0–∞ were not significantly different (p = 0.2). The bioavailability of the tablet calculated from saliva and serum was 93% and 102%, respectively. The bioavailability of the capsule calculated from saliva and serum was 113% and 102% respectively. Our data suggests that theophylline bioavailability can be reliably estimated from saliva theophylline concentrations. However, study designs that include larger sample sizes and more frequent sampling may be necessary when determining bioavailability from saliva.

Pharmaceutical Care Practice

Radioimmunoassay (RIA) and fluorescent polarization immunoassay (FPI) methods for quantitative gentamicin serum concentration assay have been shown to be comparable. The purpose of this study was to determine if serum concentration-time data from the same patients assayed by RIA and FPI would provide the same estimates for half-life, elimination rate constant, distribution volume, drug clearance, and gentamicin dose. A total of 99 preand postinfusion serum samples were obtained from 30 patients. Samples were divided and assayed by RIA or FPI, and the resultant serum concentration-time data were fitted to a standard one-compartment model. The correlation between the two assay methods was 0.99 (p < 0.005). A mean difference of 10% was seen in distribution volume, gentamicin clearance, and gentamicin dose from quantitative data from the two methods. These differences were significant (p < 0.01). Although the two methods appear to be interchangeable, based on in vitro comparison, differences in calculated pharmacokinetic parameters resulted in significant differences in dose recommendations.