Biomedical subjects

Bruce L Lambert

Publications and source records attributed to Bruce L Lambert.

8 recordsLinked to original sources

PubMed2006

Diabetes risk associated with use of olanzapine, quetiapine, and risperidone in veterans health administration patients with schizophrenia.

To evaluate risk of new-onset type 2 diabetes associated with use of selected antipsychotic agents, the authors conducted a new-user cohort study in a national sample of US Veterans Health Administration patients with schizophrenia (and no preexisting diabetes). The authors studied 15,767 patients who initiated use of olanzapine, risperidone, quetiapine, or haloperidol in 1999-2001 after at least 3 months with no antipsychotic prescriptions. Patients were followed for just over 1 year. New-onset diabetes was identified through diagnostic codes and prescriptions for diabetes medication. In Cox proportional hazards regression adjusting for potential confounders, with patients initiating haloperidol use designated the reference group, diabetes risk was increased equally with new use of olanzapine (hazard ratio (HR) = 1.64, 95% confidence interval (CI): 1.22, 2.19), risperidone (HR = 1.60, 95% CI: 1.19, 2.14), or quetiapine (HR = 1.67, 95% CI: 1.01, 2.76). Diabetes risks were higher in patients under age 50 years. When data were reanalyzed with prevalent-user cohorts and matched case-control designs, results were similar, with slightly less elevated risk estimates. Assuming that the observed associations are causal, approximately one third of new cases of diabetes may be attributed to use of olanzapine, risperidone, and quetiapine in patients taking these medications. Prescribers should be mindful of diabetes risks when treating patients with schizophrenia.

Antipsychotic Agents↗

PubMed2005

Antipsychotic exposure and type 2 diabetes among patients with schizophrenia: a matched case-control study of California Medicaid claims.

PURPOSE: To examine the risk of developing type 2 diabetes mellitus among people with schizophrenia exposed to atypical antipsychotics (clozapine, olanzapine, quetiapine, risperidone) compared to those exposed to conventional antipsychotics. METHODS: A matched case-control design was used to examine California Medicaid beneficiaries. Cases developed diabetes subsequent to being diagnosed with schizophrenia (ICD-9295), were 18 years or older, and were exposed to at least one antipsychotic medication at some point during the 12 weeks preceding diabetes diagnosis. Diabetes was defined by diagnostic claim (ICD-9250) or prescription for antidiabetic agents. A total of 3663 cases were matched to 14 523 non-diabetic controls (people with schizophrenia matched on gender and age +/-5 years). All had to be continuously eligible for benefits during the 12-week period preceding diabetes onset in the case. Conditional logistic regression modeled the risk of exposure, controlling for age, ethnicity, and exposure to selected concomitant medications. Analyses were repeated with 24- and 52-week exposure windows. RESULTS: Using a 12-week exposure window, olanzapine (OR = 1.36, 95%CI 1.20-1.53), clozapine (OR = 1.34, 95%CI 1.16-1.55), and combination atypical therapy (OR = 1.58, 95%CI 1.33-1.88), but not risperidone or quetiapine, were associated with increased odds of developing diabetes compared to conventional antipsychotics. Changing to a 24-week exposure window, the risks were: olanzapine (OR = 1.38, 95%CI 1.22-1.56), clozapine (OR = 1.32, 95%CI 1.14-1.53), or combinations (OR = 1.54, 95%CI 1.29-1.84). With a 52-week exposure window, the risks were: olanzapine (OR = 1.41, 95%CI 1.24-1.60), clozapine (OR = 1.41, 95%CI 1.21-1.65), combinations (OR = 1.58, 95%CI 1.31-1.90). Risk for olanzapine increased with dose. Hispanic, African American, and unknown ethnicity were significant risks for development of type 2 diabetes as was exposure to selected concomitant medications. CONCLUSIONS: Exposure to olanzapine or clozapine is associated with a 34-41% increase in the developing of type 2 diabetes among California Medicaid recipients with schizophrenia. Prospective, randomized trials are needed to confirm these retrospective, observational findings.

Adolescent↗

PubMed2005

An inquiry into medication meanings, illness, medication use, and the transformative potential of chronic illness among African Americans with hypertension.

BACKGROUND: Hypertension is a chronic illness with serious economic and clinical consequences. The asymptomatic nature of this condition contributes to the challenge of persistent medication use. OBJECTIVES: The objectives of this qualitative study were to explore perceptions of medication meanings, illness, identity, and biographical disruption among people with hypertension, and to examine how salient themes and categories relate to medication use. METHODS: In-person interviews were conducted with 20 participants. Eligibility criteria included being 18 years or older, diagnosed with hypertension, and currently taking antihypertensive drug treatment. Interviews were tape-recorded and transcribed. Data were analyzed with grounded theory methodology using coding techniques and constant comparison. RESULTS: All participants were African American and most were between 45 and 64 years. Key themes including perceptions of the medication being effective, lifesaving, part of life, and a reminder of the regimen were found to have a positive impact on medication use. Themes including fear of side effects, fear of dependency, forgetting to take medication, the medication being a hassle, and the experience of medication-related sexual side effects were found to be negatively related to medication use. Participants were cognizant of consequences of uncontrolled hypertension, and illness control was important to them. Biographical disruption was minimal. Taking medications and changing diet were the most significant changes in the lives of participants after being diagnosed with hypertension. Achievement of lifestyle modifications had a positive impact on identity. CONCLUSIONS: Findings contribute to our understanding of medication use behavior and have implications for patient education and counseling.

Black or African American↗

PubMed2005

Association between antipsychotic treatment and hyperlipidemia among California Medicaid patients with schizophrenia.

OBJECTIVE: To examine the risk of hyperlipidemia among people with schizophrenia exposed to new antipsychotics (clozapine, olanzapine, quetiapine, risperidone) compared with those exposed to older generation antipsychotics. METHODS: A case-control study of Medi-Cal claims. Cases developed hyperlipidemia after being diagnosed with schizophrenia (ICD-9: 295) and were exposed to only one antipsychotic drug at some point within 12 weeks prior to the hyperlipidemia diagnosis. Hyperlipidemia was defined by diagnostic claim (ICD-9: 272.1-272.4) or prescription claim for antilipemic agents. Cases were matched on gender and age +/- 3 years to patients with schizophrenia who did not develop hyperlipidemia. Conditional logistic regression assessed the risk of antipsychotic exposure, controlling for age, ethnicity, prior type 2 diabetes or hypothyroidism, and exposure to other medications that may cause hyperlipidemia. Analyses were repeated using a 24- and 52-week retrospective exposure windows. RESULTS: For the 12-week exposure window, olanzapine (OR = 1.20, 95% CI 1.08-1.33) was associated with increased risk of developing hyperlipidemia compared with older antipsychotic medications. Exposure to clozapine (OR = 1.16, 95% CI 0.99-1.37), risperidone (OR = 1.00, 95% CI 0.90-1.12), and quetiapine (OR = 1.01, 95% CI 0.78-1.32) was not. Hypothesis tests comparing the 4 atypicals to one another revealed that the odds ratio for olanzapine was greater than that for risperidone (P = 0.002). Other than clozapine's odds ratio being significant at 24 weeks (OR = 1.22, 95% CI 1.03-1.45), increasing the exposure window to 24 or 52 weeks did not substantially alter the results. CONCLUSIONS: Compared with older generation antipsychotics, exposure to olanzapine and, somewhat less consistently, to clozapine is associated with an increased risk of hyperlipidemia among people with schizophrenia.

Adolescent↗

PubMed2005

Designing safe drug names.

Recent observational studies of medication errors in community pharmacies suggest that 'wrong drug' errors, which occur when a patient receives a drug other than the one prescribed, may occur as many as 3.9 million times per year in the US. Similarity between drug product attributes, especially similarity between drug names, is thought to be a contributing cause of these errors. The challenge facing drug companies is to design new drug names that will not be confused with existing names. In this paper, we attempt to lay out a systematic approach to the design of safe drug names by characterising the process of design as a multiple-objective optimisation problem. We then identify and define the most important constraints (both technical and legal/regulatory) and objectives (such as meaning, memorability, and pronouncability) that a drug name must satisfy and critique methods for evaluating a given name with respect to each safety objective and constraint. There are a variety of preapproval tests that can be done on a name to test its vulnerability to confusion. These include computerised searches for existing similar names or products, soliciting expert judgements, doing traditional psycholinguistic tests on memory and perception and observing error rates during simulated ordering, dispensing and administration tasks. A different set of strategies is needed to prevent confusion between similar names that are already in use. Preventing confusion between already marketed products typically involves collecting voluntary reports of names involved in confusion errors, posting warnings and alerts both electronically and in areas where drugs are used, including the indication on the prescription, storing confusing drugs in different locations, improving lighting, providing magnifiers, removing one of the confusing drugs from the system or insisting on double-checking for products thought to be vulnerable to confusion.Finally, since no single design will be optimal with respect to all of the objectives, we describe several approaches to selecting one design from a set of competing alternatives. The pharmaceutical industry and the US FDA have taken important steps recently to improve the preapproval screening of new drug names, but a great deal of research still needs to be done to establish a valid scientific basis for these decisions.

Confusion↗

PubMed2004

A system for multiattribute drug product comparison.

We describe a system for multiattribute drug product searching. We then demonstrate the system's performance on sample queries, and evaluate the name-based similarity searching component. Ten drug names were used to query a database of existing drug names using five different retrieval methods. Retrieved names were merged into master lists and presented to 15 pharmacists. Pharmacists rated the similarity between the query name and each retrieved names on a scale of 1-5. We report the precision of our five different retrieval methods at 11 levels of recall. The best single measure was editex, with a precision of 17.4% averaged across 11 levels of recall. A regression model using four objective measures of similarity as predictors accounted for 40.6% of the variance in observed mean similarity ratings. Automated, multiattribute drug product searching may improve the effectiveness and efficiency of preapproval screening processes and thereby prevent medication errors.

Dosage Forms↗

PubMed2003

Immediate free recall of drug names: effects of similarity and availability.

The prescribing frequency, subjective familiarity, and two measures of similarity as predictors of error in immediate free recall of drug names were assessed. The study design utilized prospective, computer-based, word memory experiments in which 30 pharmacists and 66 college students were asked to immediately recall 15 lists of three three-syllable drug names. Intralist similarity was systematically varied. The number of words forgotten or incorrectly recalled was then examined as a function of similarity, subjective familiarity, and prescribing frequency. The primary outcome measure was the number of item errors in free recall. Pharmacists made fewer errors than college students. Familiarity reliably enhanced item recall among both pharmacists and college students. Prescribing frequency enhanced recall among both pharmacists and college students except when college students recalled generic names. Orthographic (i.e., spelling) similarity was reliably associated with item recall in both groups. Fewer errors were made when lists were more orthographically similar. Among pharmacists, there was an inverted U-shaped relationship between phonologic (i.e., sound) similarity and item errors, with the fewest errors being made on the most similar lists. Among college students, phonologic similarity was not reliably associated with item errors. Frequently prescribed and subjectively familiar drug names are more accurately recalled than rarely prescribed and unfamiliar names. Orthographically similar lists of drug names are easier to recall than dissimilar lists because similarity provides cues that facilitate the retrieval of degraded short-term memories. The effects of similarity, familiarity, and frequency on short-term memory of drug names vary as a function of task and stimulus characteristics.

Humans↗

PubMed2003

Effects of frequency and similarity neighborhoods on pharmacists' visual perception of drug names.

To minimize drug name confusion errors, regulators, drug companies, and clinicians need tools that help them predict which names are most likely to be involved in confusions. Two experiments, carried out in the United States, examined the effects of stimulus frequency (i.e., how frequently a target name is prescribed), neighborhood frequency (i.e., how frequently prescribed are the "neighbors" of the target name), and neighborhood density (how many names are within a fixed distance of the target name) on the probability of pharmacists making an error in a visual perceptual identification task. In both experiments, the task was to correctly identify a series of blurry drug names after a 3s presentation on a computer monitor. In the first experiment, 45 pharmacists viewed 160 typewritten names, incorrectly identifying 60.6% of them. Random effects regression revealed a significant beneficial effect of stimulus frequency and a detrimental effect of neighborhood density. Significant two-way interactions were observed between stimulus frequency and neighborhood density and neighborhood frequency and neighborhood density. In the second experiment, 37 pharmacists viewed 156 handwritten drug names, incorrectly identifying 45.7%. Random effects regression revealed significant main effects of stimulus frequency and neighborhood density. These were contained within a significant three-way interaction: The interaction between stimulus frequency and neighborhood density was present at high but not low neighborhood frequency. Objectively measurable frequency and neighborhood characteristics have predictable effects on errors in pharmacists' visual perception. Organizations that coin and evaluate drug names, as well as hospitals, pharmacies, and health systems, should consider these characteristics when assessing visually confusing names.

Decision Making↗