David M. Collins

A randomised controlled trial of medication liaison services - patient outcomes

Objectives: To evaluate the effects of a Medication Liaison Service (MLS) on quality of medication‐related information associated with hospital admission, risk of drug misadventure and other patient outcomes, and health resource utilisation.

Ten Years of Antipsychotic Prescribing to Children: A Canadian Population-Based Study:

Objective: To report the prescribing of antipsychotics to the youth population of the Canadian province of Manitoba during the course of a decade. Methods: Use of antipsychotics in children and adolescents (aged 18 years or younger) was described using data collected from the administrative health databases of Manitoba Health and the Statistics Canada census between the fiscal years of 1999 and 2008. Results: The prevalence of antipsychotic use in this segment of the population increased with the introduction of the second-generation antipsychotics (SGAs) from 1.9 per 1000 in 1999 to 7.4 per 1000 in 2008. The male-to-female antipsychotic usage ratio increased from 1.9 to 2.7 as the male youth population represented the fastest-growing subgroup of antipsychotic users in the entire population of Manitoba. The total number of prescriptions also increased significantly despite the lack of approved indications in this population. Proportion of use remained equally split between high- and low-income users. More than 70% of antipsychotic prescriptions to children and adolescents were written by general practitioners. The most common diagnoses linked to antipsychotic use were attention-deficit hyperactivity disorder and conduct disorders. Use of antipsychotics in combination with methylphenidate increased from 13% to 43%. Conclusion: Extensive off-label use of SGAs has been observed in the youth population of Manitoba for treatment of aggressive behaviours across a range of diagnoses. It is important to monitor antipsychotic prescribing to children as more reports of significant adverse events associated with antipsychotics become available.

Utilization and Costs of Antipsychotic Agents: A Canadian Population-Based Study, 1996–2006

OBJECTIVE This study evaluated the prescribing patterns and costs for antipsychotic agents in the population of the Canadian province of Manitoba over the past decade. METHODS A population-based study of antipsychotic utilization and costs was conducted on data collected from the administrative databases of the Manitoba Population Health Data Repository and the Statistics Canada census between index years 1996 and 2006 (April 1, 1995, through March 31, 2006). RESULTS The total annual number of antipsychotic prescriptions dispensed in Manitoba increased by 227% between 1996 and 2006, and the prevalence of antipsychotic users increased by 62% over the same time interval. The fastest-growing segment of antipsychotic users in Manitoba appears to be young males, who increased from .16% in 1996 to .88% in 2006. The highest numbers of prescriptions were reported for schizophrenia, dementia, and conduct disorder. Annual expenditures for antipsychotics increased from

Long-term stability of epinephrine dispensed in unsealed syringes for the first-aid treatment of anaphylaxis

1.7 million in 1996 to

A randomised controlled trial of medication liaison services - acceptance and use by health professionals

22.0 million in 2006 (expenditures are in Canadian dollars). The cost of second-generation agents reached 80% of total antipsychotic expenditures in 2006; risperidone was the most prescribed agent in all age groups of patients. The per-patient annual cost of antipsychotic pharmacotherapy increased by approximately 680% between 1996 and 2006 in Manitoba. CONCLUSIONS The number of antipsychotic prescriptions and the prevalence of users of antipsychotic medications increased significantly in Manitoba over the study period, despite a steady-state population of approximately 1.2 million. Incremental costs relative to the use of antipsychotic medications can be explained by the market penetration of the second-generation agents and their expanded use in the treatment of various diagnoses.

A population-based study of the use of selective serotonin reuptake inhibitors before and after introduction of generic equivalents.

BACKGROUND When epinephrine autoinjectors are unavailable or unaffordable, patients at risk for anaphylaxis in the community are sometimes provided with an unsealed syringe containing a premeasured epinephrine dose for use in first-aid treatment of anaphylaxis episodes. OBJECTIVES To study the stability of epinephrine solution in unsealed syringes under conditions of high ambient temperature, low vs high humidity, and light vs dark. METHODS Forty unsealed syringes each containing an epinephrine dose of 0.3 mg (as a 1-mg/mL epinephrine solution) were stored at 38 degrees C for 5 months, with 10 syringes at each of 4 different standardized storage conditions: dark and light at low (15%) humidity and dark and light at high (95%) humidity. Duplicate syringes were removed monthly from each storage environment and analyzed for epinephrine content vs control syringes. RESULTS The epinephrine dose, expressed as the percentage remaining of the mean control dose, was below compendial limits (90% to 115% of label claim) by 3 months after storage at 38 degrees C and low humidity and by 4 months after storage at 38 degrees C and high humidity. Light had no significant effect. CONCLUSION In hot climates, if an unsealed syringe prefilled with an epinephrine dose is provided for the first-aid treatment of anaphylaxis, it should be replaced every few months on a regular basis with a new syringe containing a fresh dose of epinephrine.

Conversion From Subcutaneous to Intravenous Erythropoietin in a Hemodialysis Population

Objectives: To determine the acceptance and utility of a Medication Liaison Service (MLS) by hospital and community healthcare professionals. The MLS aimed to improve the quality and transfer of medication‐related information associated with hospital admission.

Erythropoietin-Alpha Dosage Requirements in a Provincial Hemodialysis Population: Effect of Switching from Subcutaneous to Intravenous Administration

Objective: Generic drugs are less expensive than their branded equivalents, but receive limited promotion. This study sought to examine how user rates of individual selective serotonin reuptake inhibitors (SSRIs) changed after the introduction of their generic equivalents. Method: Administrative health and census data were used to examine the rates of use of all 6 SSRIs from 1996 to 2009 in the province of Manitoba (population of 1.2 million). The primary outcome measure was a comparison of the rates of use in the pre- and post-generic periods, using generalized estimating equations. Secondary analyses were stratified by specialty of physician prescriber. Results: Escalating rates of use of branded SSRIs in the pre-generic period significantly decreased after generic versions became available (all Ps < 0.001). Incident use of sertraline and paroxetine continued to decrease throughout the post-generic period (1.5% and 1.9% quarterly decreasing rates, respectively). During the years when generic sertraline, fluoxetine, and fluvoxamine were available, their use declined while branded paroxetine and citalopram use continued to increase. Use of branded citalopram, sertraline, and paroxetine prescribed by general practitioners (GPs) increased at rates significantly higher than when prescribed by psychiatrists (all Ps < 0.001). Conclusion: The introduction of cheaper generic alternatives of SSRIs paradoxically resulted in their use diminishing rather than increasing. With the exception of escitalopram, branded SSRIs tended to be preferentially used, compared with available less expensive generic SSRIs. These patterns were more pronounced for prescriptions by GPs.

Second-Generation Antipsychotic Agents: A Review of Safety Profiles

The purpose of this study was to compare erythropoietin dosage requirements during subcutaneous versus intravenous administration in a hemodialysis population. Hemodialysis patients receiving subcutaneous epoetin alfa were switched to the intravenous route using a prospective, crossover design. Baseline anemia parameters were measured at months −2, −1, and 0 when patients were receiving subcutaneous dosing and compared to months 4, 5, and 6 after the switch to intravenous dosing. Ninety‐eight patients were enrolled into the study with an average age of 54.8 years. Over the course of the study, 34 patients were excluded from analysis, leaving 64 patients with complete hemoglobin and erythropoietin dosing data throughout the subcutaneous and intravenous evaluation periods. In these patients, the dose of erythropoietin increased significantly from the subcutaneous to the intravenous period (7567.7 to 10229.2 IU/wk). The conversion of hemodialysis patients from the subcutaneous to the intravenous route of administration significantly increased epoetin alfa dosage requirements.

Use of benzodiazepines and related drugs in Manitoba: a population-based study

Background: The purpose of this initiative was to compare erythropoietin-α doses in hemodialysis patients who changed from subcutaneous to intravenous administration. The Manitoba Renal Program switched routes due to concern about erythropoietin-associated pure red cell aplasia. Methods: We compared the erythropoie tin-α dosage requirements during subcutaneous administration (3 months pre-switch) and intravenous administration (months 4–6 post-switch). We also compared: hemoglobin, transferrin saturation (Tsat%), ferritin, and percent of patients receiving intravenous iron. The same erythropoietin-α regimen was initially used when patients were switched. Results: Of the 628 patients receiving erythropoietin-α, the data were complete for 400. The dose increased 26% (mean ± SD, 10,425 ± 7,330 vs. 13,125 ± 8,638 IU/week; p < 0.0001), despite similar hemoglobin, (mean ± SD, 11.5 ± 1.1g/dl (114.9 ± 11.2 g/l) vs. 11.3 ± 1.0 g/dl (113.5 ± 10.4 g/l); p = 0.0450) and iron parameters (Tsat 30.9%, ferritin 464 ng/ml (µg/l) vs. Tsat 28.7%, ferritin 538 ng/ml (µg/l)). For the subgroup of 84 patients who maintained target hemoglobin (10–11 g/dl or 110–120 g/l) for both periods, the dose increased 26% (mean ± SD, 8,393 ± 6,242 vs. 10,589 ± 7,049 IU/week; p < 0.0001) without a change in hemoglobin, (mean ± SD, 11.5 ± 0.3 g/dl (115.2 ± 3.0 g/l) vs. 11.5 ± 0.3 g/dl (114.9 ± 3.3 g/l); p = 0.5789). When stratified by subcutaneous dose, patients with the lowest dose (<5,000 IU/week) demonstrated the greatest increase (89%), and those with the highest dose (>20,000 IU/week) experienced no increase (–3%). Conclusion: Overall, erythropoietin-α doses increased by 26% when patients were converted from subcutaneous to intravenous administration.