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Biomedical subjects

Allen Brinker

Publications and source records attributed to Allen Brinker.

15 recordsLinked to original sources

New-onset and idiopathic thrombotic thrombocytopenic purpura: incidence, diagnostic validity, and potential risk factors.

OBJECTIVE: The aim of this study was to determine the incidence rate for new-onset and idiopathic thrombotic thrombocytopenic purpura (TTP) among adults 20-64 years old, the validity of diagnostic criteria, and potential risk factors for TTP. METHODS: This retrospective observational study analyzed automated administrative data from 11 geographically dispersed U.S. health plans. Cases of TTP were identified based on the presence of an inpatient hospital claim for TTP (ICD-9-CM 446.6) between 1/1/97 and 12/31/01 and confirmed by medical record review. Pharmacy and medical claims were used to evaluate outpatient drug exposure and comorbidities preceding hospitalization for TTP. Cases and the base population were screened so as to result in an incidence rate for idiopathic TTP. RESULTS: We confirmed new-onset and idiopathic TTP in 9 of 15 presumptive cases for an incidence density of 1.4 per million person-years (95% CI: 0.6-2.6). The rate increased to 1.8 per million person-years after projection and age-standardization. The highest incidence rate of TTP was found in patients 50-64 years old (2.8 per million person-years; 95% CI: 0.8-7.1). These 9 patients had no apparent risk factors for TTP based on claims and medical record data. CONCLUSIONS: In a general U.S. population, the incidence rate of confirmed new-onset and idiopathic TTP was lower than previously reported, but appears to be on the rise. Our findings suggest that administrative claims data are useful for identifying outpatient drug exposures and comorbidities potentially associated with TTP.

Adult↗

Alosetron: ischemic colitis and serious complications of constipation.

Drugs such as alosetron that modulate serotonin effects by stimulating or blocking its receptors may play an important role in the treatment of some patients with irritable bowel system. In the case of alosetron, a 5HT-3 antagonist, an analysis of data from randomized clinical trials and postmarketing experiences have demonstrated a causal relationship between this drug and ischemic colitis and serious complications of constipation. Because the mechanism(s) of drug-induced ischemic colitis and possibly other forms of intestinal ischemia associated with alosetron have not been elucidated, there is need to further assess risk with regard to patient susceptibility and other factors.

Carbolines↗

Trends in adherence to a revised risk management program designed to decrease or eliminate isotretinoin-exposed pregnancies: evaluation of the accutane SMART program.

OBJECTIVE: To review adherence to selected procedures outlined in the System to Manage Accutane-Related Teratogenicity (SMART) program during the first year of implementation vs the procedures in effect in the year prior to initiation of the SMART program. DESIGN: Observational. SETTING: A novel pharmacy compliance survey and an ongoing, voluntary survey. PATIENTS: Female recipients of isotretinoin. INTERVENTION: In April 2002, Hoffmann-La Roche Inc, Nutley, NJ, manufacturer of Accutane brand isotretinoin and at that time the sole source of isotretinoin, revised earlier guidelines and instituted the SMART risk management program, which included the use of qualification stickers to affix to all prescriptions for Accutane to indicate, among other things, a negative pregnancy test just before the prescription was written. The goal of the SMART program was to decrease or eliminate isotretinoin-exposed pregnancies. MAIN OUTCOME MEASURES: Use and completion of prescription qualification stickers; changes in pretherapy pregnancy testing and birth control use. RESULTS: The results of the pharmacy compliance survey indicated high (>90%) use of prescription qualification stickers. Results of the patient survey suggested that 9% of prescription qualification stickers within the observed user cohort were issued without a pregnancy test. Furthermore, the pregnancy rate for patients participating in the survey was similar to that reported for cohorts recruited before the SMART program. CONCLUSIONS: The usefulness of the results derived from 2 surveys designed to evaluate the SMART program is limited by the lack of reliability and validity of the survey instruments and by questionable generalizability to all female recipients of isotretinoin. The presence of a qualification sticker may not have an impact on pregnancy testing or compliance with effective birth control behavior as outlined in the SMART program.

Abnormalities, Drug-Induced↗

Comparison of reporting of Stevens-Johnson syndrome and toxic epidermal necrolysis in association with selective COX-2 inhibitors.

BACKGROUND: Stevens-Johnson syndrome and toxic epidermal necrolysis are closely related severe acute life-threatening, drug-induced skin disorders. The US FDA Adverse Events Reporting System (AERS) has received reports of Stevens-Johnson syndrome and toxic epidermal necrolysis associated with the use of the recently introduced selective cyclo-oxygenase (COX)-2 inhibitor NSAIDs, two of which are also sulfonamides. OBJECTIVE: The objective of this study is to review cases of Stevens-Johnson syndrome and toxic epidermal necrolysis reported to the FDA associated with the use of the selective COX-2 inhibitor NSAIDs celecoxib, rofecoxib and valdecoxib, and to compare reporting rates of the two conditions associated with these drugs to each other, meloxicam (an oxicam NSAID that came on the US market at a similar time) and the background incidence rate. METHODS: We reviewed all US cases of Stevens-Johnson syndrome and toxic epidermal necrolysis reported to the FDA AERS database associated with the use of celecoxib, rofecoxib, valdecoxib and meloxicam since these agents were first marketed. We utilised AERS and drug use data to calculate reporting rates for each drug after the first 2 years of marketing. We obtained the background rate from the medical literature. RESULTS: Up to the end of March 2004, there were 63 cases of Stevens-Johnson syndrome/toxic epidermal necrolysis reported with valdecoxib use, 43 with celecoxib, 17 with rofecoxib (the non-sulfonamide coxib) and none for meloxicam. In the first 2 years of marketing the reporting rate for Stevens-Johnson syndrome/toxic epidermal necrolysis with valdecoxib was 49 cases per million person-years of use, 6 cases per million person-years for celecoxib and 3 cases per million person-years for rofecoxib. The reporting rates for the sulfonamide coxibs were substantially higher than the background rate of 1.9 cases per million population per year, with the valdecoxib rate being 8-9 times that of celecoxib and approximately 25 times that of the background rate. CONCLUSION: There is a strong association between Stevens-Johnson syndrome/toxic epidermal necrolysis and the use of the sulfonamide COX-2 inhibitors, particularly valdecoxib. Physicians should be aware of the possibility of this serious life-threatening event when prescribing these drugs and advise patients to discontinue use at the earliest possible sign or symptom.

Adolescent↗

Spontaneous reports of hypertension leading to hospitalisation in association with rofecoxib, celecoxib, nabumetone and oxaprozin.

BACKGROUND AND OBJECTIVE: Data on file with the US FDA, and other published studies, suggest that the selective cyclo-oxygenase (COX)-2 inhibitor NSAID rofecoxib has a greater hypertensive adverse effect than other NSAIDs, including celecoxib. In this study we describe a pharmacoepidemiologic analysis of spontaneous adverse event reports of acute, clinically serious hypertension (as defined by hospitalisation) reported in association with rofecoxib, celecoxib, nabumetone and oxaprozin. The objective of this analysis is to assess whether postmarketing data are consistent with results of clinical trials. We also collapse cases into series for the identification of possible risk factors for clinically severe, NSAID-associated hypertension. METHODS: Domestic (US) cases of apparently unconfounded, acute hypertension leading to hospitalisation were collected and reviewed from the spontaneous adverse events database of the FDA for rofecoxib, celecoxib, nabumetone and oxaprozin for the initial 3 years of marketing. Drug use data for the same intervals enabled calculation of reporting rates. RESULTS: In an analysis of reporting rates, hospitalisation for acute blood pressure (BP) elevation was reported more frequently (3.8-fold) for rofecoxib compared with celecoxib. A total of 34 cases are collapsed into case series. No cases were identified for either nabumetone or oxaprozin. Inspection of reviewed cases for celecoxib and rofecoxib suggest that these patients (average age 72 years) were potentially high-risk candidates for NSAID therapy. DISCUSSION AND CONCLUSION: During early marketing, hospitalisation for acute BP elevation appears to have been reported more frequently for rofecoxib compared with celecoxib. This is consistent with clinical trial data on file with the FDA, and other published studies that found rofecoxib to have a greater effect on BP than other NSAIDs, including celecoxib. This finding may be particularly relevant in older patients given the prevalence of hypertension and cardiovascular disease in this age group.

Adult↗

Use of a spontaneous adverse drug events database for identification of unanticipated drug benefits.

We describe an examination of a spontaneous adverse events database in an effort to identify agents with possible hitherto unknown antiangiogenic properties. The surrogate end point was abnormal wound healing. This analysis represents use of this database for identification of a possibly useful in vivo side effect. Through thoughtful choice of end points, we believe spontaneous adverse events databases have the capacity for hypothesis generation in a search for unanticipated beneficial drug properties.

Adverse Drug Reaction Reporting Systems↗

Ambulatory use of ticlopidine and clopidogrel in association with percutaneous coronary revascularization procedures in a national managed care organization.

The aim of this study was to quantify ambulatory use of ticlopidine and clopidogrel in association with percutaneous coronary revascularization procedures (PTCA, atherectomy, stent) in a national managed care organization. Retrospective administrative claims data over a 3-year period (1996-1998) from 12 UnitedHealth Group-affiliated health plans in four geographic regions were collected. Pharmacy and medical claims data were used to determine the patients exposed to ticlopidine and clopidogrel between January 1, 1996 and December 31, 1998, the duration of use, prescriptions within 2 weeks of a coronary procedure, and stent patients prescribed either drug within 2 weeks of stent placement in 1998. Substantial short-term use of ticlopidine and clopidogrel was found. The percentage of members with duration of use < or = 30 days ranged from 50.4% in 1996 to 56.9% in 1998 for ticlopidine and was 52.7% for clopidogrel. In 1998, 46% and 33% of ticlopidine and clopidogrel users, respectively, had a medical claim for a coronary procedure that fell within 2 weeks of a prescription. The rate was lower for Medicare beneficiaries. In 1998, 78% of stent patients filled a prescription for either drug within 2 weeks of stent implantation. Although little difference was found overall in the use of these agents across geographic regions, a higher proportion of stent patients in the Southeast were prescribed ticlopidine within this time frame. The findings suggest that during the study time period ticlopidine and clopidogrel are frequently used off-label in association with percutaneous coronary revascularization procedures. These results were important in considering the overall benefit-risk profile.

Angioplasty, Balloon, Coronary↗

Renal failure associated with the use of celecoxib and rofecoxib.

OBJECTIVE: Celecoxib and rofecoxib are two relatively new nonsteroidal anti-inflammatory drugs (NSAIDs) that selectively inhibit the cyclo-oxygenase-2 (COX-2) isoenzyme at therapeutic concentrations. The nephrotoxic potential of selective COX-2 inhibitors has not been clearly established. This study was conducted in order to understand the association between acute renal failure and the two COX-2 inhibitors celecoxib and rofecoxib. METHODS: A search was performed in the US Food and Drug Administration's (FDA) Adverse Event Reporting System (AERS) to identify cases of renal failure submitted to the FDA. A MEDLINE search of the English language literature was also performed to identify published cases of renal failure associated with celecoxib and rofecoxib. RESULTS: One hundred twenty-two and 142 domestic US cases of celecoxib and rofecoxib-associated renal failure, respectively, were identified in the AERS database. The literature search identified 19 cases of acute renal impairment in association with celecoxib and rofecoxib. In addition, drug regulatory authorities in the UK, Canada, and Australia have received about 50 reports of renal failure with celecoxib and rofecoxib. Descriptive statistics of the AERS cases have been summarised in this report. CONCLUSIONS: Data from AERS and published case reports suggest that use of both these drugs is associated with renal effects similar to that of conventional nonselective NSAIDs. Physicians should be aware that serious or life-threatening renal failure has been reported in patients with normal or impaired renal function after short-term therapy with celecoxib and rofecoxib. Patients at greatest risk for renal injury are those with pre-existing renal impairment, heart failure, liver dysfunction, those taking diuretics and/or ACE inhibitors, and the elderly. Kidney function should be monitored closely for any signs of potential renal injuries soon after initiating treatment with these agents, especially in high-risk populations. In addition, healthcare practitioners should adequately warn patients of the signs and symptoms of serious renal toxicity, and of the need for them to see their physician promptly if they occur. Celecoxib and rofecoxib are not recommended for use in patients with advanced renal disease.

Adverse Drug Reaction Reporting Systems↗

Changes in ciprofloxacin utilization as shown in a large pharmacy claims database: effects of proximity to criminal anthrax exposure in October 2001.

OBJECTIVE: Identify, during the period of criminal anthrax exposures in October 2001, changes in utilization of ciprofloxacin and geographic patterns of any identified variations. DESIGN: Observational. SETTING: United States. PATIENTS: Individuals making prescription claims through a pharmacy benefits management company. INTERVENTIONS: Analysis of AdvancePCS pharmacy claims database. MAIN OUTCOME MEASURES: Percentage change in ciprofloxacin utilization for 2000 and 2001 and, by locale, for September and October 2001. RESULTS: Utilization of ciprofloxacin tablets was significantly lower in calendar year 2001 than in calendar year 2000 (median decline, 10.3%) for all months except October, when utilization of ciprofloxacin increased 9.8%. During the period of anthrax exposures (October 2001 versus September 2001), affected geographic areas, including New York (an increase of 62.5%), some other Mid-Atlantic states, and Florida (28.5%), had some of the highest percentage increases in the rate of ciprofloxacin utilization. CONCLUSION: Many Americans actively sought prophylaxis with ciprofloxacin during the course of the October 2001 anthrax attack and that utilization was higher in, but not limited to, locales with publicized cases of disease. Pharmacists, clinicians, and public health officials should note that such behavior may be expected in the event of a similar attack and should be familiar with current recommendations for the assessment and management of anthrax exposure.

Analysis of Variance↗