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1.
Clin Microbiol Infect ; 26(3): 327-332, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31600582

ABSTRACT

OBJECTIVES: Antimicrobial stewardship programmes have focused on reducing inappropriate inpatient antimicrobial prescribing, but several small studies have found a large portion of antimicrobial exposure occurs immediately after hospital discharge. In this study, we describe the prescribing of oral antimicrobials at hospital discharge across an integrated national healthcare system. At the hospital level, we also compare total inpatient antimicrobial use and post-discharge oral antimicrobial use. METHODS: This retrospective cross-sectional study used national administrative data to identify all acute-care admissions during 2014-2016 within the Veterans Health Administration (VHA). We evaluated inpatient days of therapy (DOT) and post-discharge DOT, defined as oral outpatient antimicrobials dispensed at the time of hospital discharge. At the hospital level, inpatient DOT/100 admissions were compared with post-discharge DOT/100 admissions using Spearman's rank-order correlation. RESULTS: There were 1 681 701 acute-care admissions across 122 hospitals, and 335 369 (19.9%) were prescribed an oral antimicrobial at discharge. Fluoroquinolones (38.3%) were the most common post-discharge antimicrobial. At the hospital level, median inpatient antimicrobial use was 331.3 (interquartile range (IQR) 284.9-367.9) DOT/100 admissions and median post-discharge use was 209.5 (IQR 181.5-239.6) DOT/100 admissions. Thirty-nine per cent of the total duration of antimicrobial exposure occurred after discharge. At the hospital-level, the metrics of inpatient DOT/100 admissions and post-discharge DOT/100 admissions were weakly positively correlated with rho=0.44 (p < 0.001). CONCLUSIONS: A large proportion of antimicrobial exposure among hospitalized patients occurred immediately following discharge. Antimicrobial-prescribing at hospital discharge provides an opportunity for antimicrobial stewardship. Hospital-level stewardship metrics need to include both inpatient and post-discharge antimicrobial-prescribing to provide a comprehensive assessment of hospital-associated antimicrobial use.


Subject(s)
Anti-Bacterial Agents , Antimicrobial Stewardship , Delivery of Health Care, Integrated/statistics & numerical data , Delivery of Health Care, Integrated/standards , Inappropriate Prescribing/statistics & numerical data , Medical Overuse/statistics & numerical data , Aged , Anti-Bacterial Agents/administration & dosage , Female , Hospitalization , Humans , Male , Middle Aged , Patient Discharge , Public Health Surveillance
2.
J Gen Intern Med ; 30(5): 597-604, 2015 May.
Article in English | MEDLINE | ID: mdl-25519224

ABSTRACT

BACKGROUND: Improved understanding of temporal and regional trends may support safe and effective prescribing of opioids. OBJECTIVE: We describe national, regional, and facility-level trends and variations in opioid receipt between fiscal years (FY) 2004 and 2012. DESIGN: Observational cohort study using Veterans Health Administration (VHA) administrative databases. PARTICIPANTS: All patients receiving primary care within 137 VHA healthcare systems during a given study year and receiving medications from VHA one year before and during a given study year. MAIN MEASURES: Prevalent and incident opioid receipt during each year of the study period. KEY RESULTS: The overall prevalence of opioid receipt increased from 18.9% of all veteran outpatients in FY2004 to 33.4% in FY2012, a 76.7% relative increase. In FY2012, women had higher rates of prevalent opioid receipt than men (42.4% vs. 32.9%), and the youngest veterans (18-34 years) had higher prevalent opioid receipt compared to the oldest veterans (≥ 80 years) (47.6% vs. 17.9%). All regions in the United States saw increased rates of prevalent opioid receipt during this time period. Prevalence rates varied widely by facility: in FY2012, the lowest-prescribing facility had a rate of 13.5%, and the highest of 50.8%. Annual incident opioid receipt increased from 8.8% in FY2004 to 10.2% in FY2011, with a decline to 9.8% in FY2012. Incident prescribing increased at some facilities and decreased at others. Facilities with high prevalent prescribing tended to have flat or decreasing incident prescribing rates during the study time frame. CONCLUSIONS: Rates of opioid receipt increased throughout the study time frame, with wide variation in prevalent and incident rates across geographical region, sex, and age groups. Prevalence and incidence rates reflect distinct prescribing practices. Areas with the highest prevalence tended to have lower increases in incident opioid receipt over the study period. This likely reflects facility-level variations in prescribing practices as well as baseline rates of prevalent use. Future work assessing opioid prescribing should employ methodologies to account for and interpret both prevalent and incident opioid receipt.


Subject(s)
Analgesics, Opioid/administration & dosage , Analgesics, Opioid/economics , Chronic Pain/drug therapy , Drug Utilization/statistics & numerical data , United States Department of Veterans Affairs/trends , Adult , Age Factors , Aged , Ambulatory Care/methods , Analgesics, Opioid/adverse effects , Chronic Pain/diagnosis , Cohort Studies , Confidence Intervals , Databases, Factual , Drug Costs/trends , Drug Overdose/epidemiology , Drug Overdose/physiopathology , Female , Hospitals, Veterans/trends , Humans , Logistic Models , Male , Middle Aged , Multivariate Analysis , Odds Ratio , Prevalence , Primary Health Care , Retrospective Studies , Risk Assessment , Sex Factors , United States
3.
Acta Psychiatr Scand ; 113(2): 135-41, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16423165

ABSTRACT

OBJECTIVE: To determine whether atypical antipsychotic polytherapy is a risk factor for drug treatment for extrapyramidal side-effects (anti-EPS drugs) and whether the risk is attributable to antipsychotic dose. METHOD: We studied Iowa Medicaid beneficiaries aged 18-64 years with an active atypical and no conventional antipsychotic on January 1, 2001. The association of atypical antipsychotic polytherapy with anti-EPS drug treatment was determined. Multiple logistic regression was utilized to adjust for covariates in two models, the first adjusting for age, sex and the specific antipsychotic(s) prescribed, and the second also adjusting for doses. RESULTS: Among 4400 patients, the unadjusted odds of anti-EPS treatment were increased two-fold with polytherapy. Polytherapy remained a risk factor in the first model (OR 1.5, 95% CI 1.1-2.0), but not after adjusting for doses (OR 1.0, 95% CI 0.7-1.4). CONCLUSION: Atypical antipsychotic polytherapy is a risk factor for anti-EPS drug treatment, apparently because of higher cumulative doses.


Subject(s)
Antipsychotic Agents/adverse effects , Basal Ganglia Diseases/chemically induced , Psychotic Disorders/drug therapy , Adolescent , Adult , Antipsychotic Agents/administration & dosage , Basal Ganglia Diseases/diagnosis , Basal Ganglia Diseases/epidemiology , Benzodiazepines/administration & dosage , Benzodiazepines/adverse effects , Clozapine/administration & dosage , Clozapine/adverse effects , Cross-Sectional Studies , Delayed-Action Preparations , Dibenzothiazepines/administration & dosage , Dibenzothiazepines/adverse effects , Drug Therapy, Combination , Female , Humans , Iowa , Male , Mathematical Computing , Medicaid , Middle Aged , Models, Statistical , Olanzapine , Product Surveillance, Postmarketing , Psychotic Disorders/epidemiology , Quetiapine Fumarate , Regression Analysis , Risk Factors , Risperidone/administration & dosage , Risperidone/adverse effects , Statistics as Topic
4.
Arch Gen Psychiatry ; 58(12): 1172-6, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11735847

ABSTRACT

BACKGROUND: Numerous case reports have linked clozapine to the development of diabetes mellitus and hyperlipidemia in patients with schizophrenia. However, investigators have been unable to clearly demonstrate this association when compared with a control group receiving conventional antipsychotics. METHODS: Medical and pharmacy claims from the Iowa Medicaid program were used to compare incidence rates for diabetes, hyperlipidemia, and hypertension in 552 patients receiving clozapine and 2461 patients receiving conventional antipsychotics (eg, haloperidol, chlorpromazine hydrochloride), with the use of a retrospective cohort design. Logistic regression was used to compare incidence rates adjusting for age, sex, and duration of available follow-up. RESULTS: No significant differences in overall incidence rates for diabetes, hyperlipidemia, or hypertension were observed in patients receiving clozapine vs conventional antipsychotics. However, among younger patients (aged 20-34 years), clozapine administration was associated with a significantly increased relative risk of diabetes (2.5 [95% confidence interval, 1.2-5.4]) and hyperlipidemia (2.4 [95% confidence interval, 1.1-5.2]), but not hypertension (0.9 [95% confidence interval, 0.4-2.0]). CONCLUSIONS: These data suggest that clozapine may not be an independent cause of diabetes or hyperlipidemia, but instead acts as an effect modifier in susceptible populations by increasing weight or affecting insulin secretion and resistance. This finding requires confirmation in other settings and patient populations and with the other atypical antipsychotics (risperidone, olanzapine, and quetiapine fumarate). The potential long-term medical and economic implications of the early induction of diabetes and hyperlipidemia in patients with schizophrenia warrant further study.


Subject(s)
Antipsychotic Agents/adverse effects , Clozapine/adverse effects , Diabetes Mellitus, Type 2/chemically induced , Hyperlipidemias/chemically induced , Hypertension/chemically induced , Schizophrenia/drug therapy , Adult , Age Factors , Antipsychotic Agents/therapeutic use , Causality , Clozapine/therapeutic use , Cohort Studies , Confidence Intervals , Cross-Sectional Studies , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/epidemiology , Female , Follow-Up Studies , Humans , Hyperlipidemias/diagnosis , Hyperlipidemias/epidemiology , Hypertension/diagnosis , Hypertension/epidemiology , Incidence , Iowa , Male , Middle Aged , Product Surveillance, Postmarketing , Retrospective Studies , Risk , Schizophrenia/diagnosis , Schizophrenia/epidemiology
6.
Pharmacotherapy ; 21(8): 1003-6, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11718487

ABSTRACT

Neuroleptic malignant syndrome (NMS) is an uncommon but potentially life-threatening adverse effect associated with conventional antipsychotic agents. The syndrome is characterized by muscular rigidity, hyperpyrexia, altered consciousness, and autonomic dysfunction. Few cases of quetiapine-induced NMS have been reported. A 54-year-old man was unsuccessfully challenged with quetiapine after conventional antipsychotic-induced NMS.


Subject(s)
Antipsychotic Agents/adverse effects , Dibenzothiazepines/adverse effects , Neuroleptic Malignant Syndrome/etiology , Alzheimer Disease/complications , Antipsychotic Agents/administration & dosage , Chlorpromazine/adverse effects , Dibenzothiazepines/administration & dosage , Haloperidol/adverse effects , Humans , Hyperthyroidism/complications , Lorazepam/adverse effects , Male , Middle Aged , Neuroleptic Malignant Syndrome/diagnosis , Neuroleptic Malignant Syndrome/physiopathology , Psychomotor Agitation/complications , Psychomotor Agitation/drug therapy , Quetiapine Fumarate
7.
Ann Clin Psychiatry ; 13(2): 75-80, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11534928

ABSTRACT

Andropause is a syndrome described in aging males, is composed of a constellation of physical, sexual, and emotional symptoms, and is thought to be related to declining concentrations of serum testosterone. Numerous studies of testosterone replacement therapy in elderly hypogonadal males have documented the physical benefits of such treatment, but have failed to assess cognition, psychological functioning, and quality of life. Male outpatients greater or equal to 55 years of age completed cognitive, psychological, sexual, and quality of life assessments. A serum sample was provided for bioavailable testosterone assay. The associations between bioavailable testosterone concentrations and neuropsychological testing were assessed using Spearman rank correlation. Overall, bioavailable testosterone was not an important determinant of cognitive, psychological, or sexual functioning or of quality of life. The implications for future studies involving testosterone replacement therapy are discussed.


Subject(s)
Cognition/drug effects , Hypogonadism/drug therapy , Quality of Life , Sexual Behavior/psychology , Testosterone/pharmacology , Testosterone/therapeutic use , Aged , Aging/physiology , Biological Availability , Humans , Middle Aged
9.
Pharmacotherapy ; 21(6): 717-30, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11401184

ABSTRACT

Although the introduction of antipsychotic drugs in 1954 was a breakthrough in the treatment of patients with schizophrenia, these agents have a number of adverse effects that limit effectiveness and compliance. The atypical antipsychotic drugs provide an improved tolerability profile, particularly in minimizing extrapyramidal side effects; however, they are associated with significant weight gain, which may be related to growing evidence linking the atypical agents with diabetes and hyperlipidemia. Ziprasidone, a new atypical antipsychotic drug, was demonstrated in clinical trials to be more efficacious than placebo and similar in efficacy to haloperidol in the treatment of schizophrenia. Like the existing atypical agents, ziprasidone has a rate of extrapyramidal side effects similar to that of placebo and does not cause significant elevations in prolactin levels. In contrast, ziprasidone has a low propensity for causing weight gain. For patients requiring an antipsychotic drug, ziprasidone represents a new treatment option with a limited adverse effect profile.


Subject(s)
Antipsychotic Agents/therapeutic use , Bipolar Disorder/drug therapy , Piperazines/therapeutic use , Schizophrenia/drug therapy , Thiazoles/therapeutic use , Tourette Syndrome/drug therapy , Antipsychotic Agents/adverse effects , Antipsychotic Agents/pharmacokinetics , Clinical Trials as Topic , Drug Interactions , Humans , Piperazines/adverse effects , Piperazines/pharmacokinetics , Psychotic Disorders/drug therapy , Thiazoles/adverse effects , Thiazoles/pharmacokinetics
10.
J Clin Psychopharmacol ; 21(1): 14-20, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11199942

ABSTRACT

Olanzapine is an atypical antipsychotic that is effective in the treatment of schizophrenia. Olanzapine plasma concentrations > or = 9.3 ng/mL (24 hours postdose) have been identified as a predictor of clinical response in acutely ill patients with schizophrenia. The authors report a receiver operating characteristic (ROC) curve analysis of 12-hour olanzapine concentrations and treatment response from the North American Double-Blind Olanzapine Trial. After a 4- to 7-day placebo lead-in, patients meeting DSM-III-R criteria for schizophrenia were randomly assigned to receive olanzapine, haloperidol, or placebo. Patients who were randomly assigned to receive olanzapine were given daily doses ranging from 2.5 to 17.5 mg/day for up to 6 weeks. Blood samples for the determination of olanzapine plasma concentrations were obtained between 10 and 16 hours (11.7 +/- 1.7 hours) after the last dose was administered. Therapeutic response data and olanzapine concentrations used for analysis were obtained from the endpoint visit for each patient if the patient had been receiving a fixed olanzapine dose for at least the last 2 weeks of the study. Plasma concentrations from previous visits were used if endpoint concentrations were invalid. Response was defined as a > or = 20% reduction in Brief Psychiatric Rating Scale (BPRS) scores and a Clinical Global Impression (CGI) Severity scale score of < or = 3 or a final BPRS score of < or = 35. The final ROC analysis included data from 84 patients and suggested an olanzapine concentration > or = 23.2 ng/mL to be a predictor of therapeutic response. Fifty-two percent of patients with 12-hour olanzapine concentrations > or = 23.2 ng/mL responded, whereas only 25% of patients with concentrations < 23.2 ng/mL responded. Furthermore, an olanzapine concentration > or = 23.2 ng/mL was a predictor of response in the Scale for the Assessment of Negative Symptoms (> or = 20% decrease and endpoint CGI < or = 3). Olanzapine concentrations were found to be a function of olanzapine dose (in milligrams per day) and gender such that prospective olanzapine dosing is feasible. A 12-hour olanzapine plasma concentration of > 23.2 ng/mL was a predictor of therapeutic response in acutely ill patients with schizophrenia. Males required a higher olanzapine dose to reach this threshold concentration than their female counterparts.


Subject(s)
Antipsychotic Agents/blood , Pirenzepine/analogs & derivatives , Pirenzepine/blood , Schizophrenia/drug therapy , Acute-Phase Reaction , Adolescent , Adult , Antipsychotic Agents/therapeutic use , Benzodiazepines , Female , Humans , Male , Middle Aged , North America , Olanzapine , Outcome Assessment, Health Care , Pirenzepine/therapeutic use , Schizophrenia/blood , Treatment Outcome
11.
Pharmacotherapy ; 21(1): 114-5, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11191731

ABSTRACT

Celecoxib, a specific inhibitor of cyclooxygenase-2, is used to treat the symptoms of arthritis. A 79-year-old woman developed an atypical visual disturbance associated with this agent that resolved on discontinuation of celecoxib. Similar visual disturbances described with the traditional nonsteroidal antiinflammatory drugs are discussed.


Subject(s)
Cyclooxygenase Inhibitors/adverse effects , Isoenzymes/antagonists & inhibitors , Sulfonamides/adverse effects , Vision Disorders/chemically induced , Aged , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Arthritis/drug therapy , Celecoxib , Cyclooxygenase 2 , Cyclooxygenase 2 Inhibitors , Cyclooxygenase Inhibitors/therapeutic use , Female , Humans , Membrane Proteins , Prostaglandin-Endoperoxide Synthases , Pyrazoles , Sulfonamides/therapeutic use
12.
Ann Clin Psychiatry ; 13(3): 129-34, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11791949

ABSTRACT

Despite the increasing recognition of attention-deficit hyperactivity disorder (ADHD) in adults, there are few controlled trials demonstrating the effectiveness of pharmacological treatments, particularly with nonstimulants. One controlled trial found bupropion SR more effective than placebo in the treatment of ADHD adults. We conducted a controlled study to contrast the effectiveness of bupropion SR and methylphenidate to placebo in ADHD adults. A randomized, double-blind, parallel design was used in this study. Following a 7-day placebo lead-in, 30 ADHD (DSM-IV) subjects (18-60 years old) were randomized to bupropion, methylphenidate, or placebo for 7 weeks. Methylphenidate was titrated over 1 week to a maximum dose of 0.9 mg/kg/d divided into 3 doses while bupropion was titrated over 2 weeks to a maximum dose of 200 mg A.M. and 100 mg P.M. Response rates based on Clinical Global Impression improvement ratings in patients receiving bupropion, methylphenidate, and placebo were 64, 50, and 27%, respectively. The difference in response rates between active treatment and placebo was not statistically significant (p = 0.14). Neuropsychological testing demonstrated trends favoring drug treatment on measures of immediate recall and verbal fluency. While bupropion SR may be a viable clinical alternative for adults with ADHD, further investigation is needed.


Subject(s)
Adrenergic Agents/therapeutic use , Attention Deficit Disorder with Hyperactivity/drug therapy , Bupropion/therapeutic use , Dopamine Uptake Inhibitors/therapeutic use , Methylphenidate/therapeutic use , Adult , Attention Deficit Disorder with Hyperactivity/psychology , Double-Blind Method , Female , Humans , Male , Neuropsychological Tests , Severity of Illness Index , Time Factors , Treatment Outcome
13.
Expert Opin Pharmacother ; 1(2): 305-23, 2000 Jan.
Article in English | MEDLINE | ID: mdl-11249551

ABSTRACT

Olanzapine is a serotonin-dopamine receptor antagonist primarily used in the treatment of psychotic illnesses. It has been shown in numerous large trials to be as equally effective as haloperidol in the acute treatment and maintenance treatment of schizophrenia. However, olanzapine was shown to be more effective than haloperidol in the treatment of negative symptoms and to cause significantly fewer extrapyramidal symptoms. Furthermore, early reports suggest that olanzapine produces less tardive dyskinesia than haloperidol, though longer follow-up data are needed. Current studies have failed to demonstrate the efficacy of olanzapine in the treatment of refractory schizophrenia. One comparison trial of olanzapine versus risperidone has indicated similar efficacy. Clinical trials in acute mania have found olanzapine to be more effective than placebo. However, there is no role for olanzapine monotherapy in bipolar disorder given current studies. Although olanzapine has shown a low rate of extrapyramidal symptoms, it is not without adverse effects. Clinically significant weight gain has been noted with olanzapine in each of the large clinical trials. The degree of weight gain is similar to clozapine and probably greater than that observed with risperidone. The long-term medical consequence of atypical antipsychotic-induced weight gain is not known at this time. While generally considered first-line drugs from an efficacy and adverse effect standpoint, pharmacoeconomic studies are needed to justify the large acquisition cost of olanzapine compared to typical agents.


Subject(s)
Antipsychotic Agents/therapeutic use , Pirenzepine/analogs & derivatives , Pirenzepine/therapeutic use , Schizophrenia/drug therapy , Antipsychotic Agents/adverse effects , Antipsychotic Agents/economics , Antipsychotic Agents/pharmacokinetics , Antipsychotic Agents/pharmacology , Benzodiazepines , Clinical Trials as Topic , Humans , Olanzapine , Pirenzepine/adverse effects , Pirenzepine/economics , Pirenzepine/pharmacokinetics , Pirenzepine/pharmacology , Schizophrenia/complications , Schizophrenia/economics , Schizophrenic Psychology
14.
Pharmacotherapy ; 19(12): 1437-8, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10600093

ABSTRACT

Pergolide is a dopaminergic agonist used to treat Parkinson's disease but is associated with the development of retroperitoneal fibrosis (RPF). Newer nonergot agents (pramipexole, ropinirole) may not carry this same risk. A patient with a history of pergolide-induced RPF was treated successfully with ropinirole for 1 year without complications.


Subject(s)
Antiparkinson Agents/therapeutic use , Indoles/therapeutic use , Parkinson Disease/drug therapy , Pergolide/adverse effects , Retroperitoneal Fibrosis/chemically induced , Aged , Aged, 80 and over , Antiparkinson Agents/adverse effects , Female , Humans , Pergolide/therapeutic use
15.
Pharmacotherapy ; 19(8): 951-6, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10453966

ABSTRACT

Andropause, a syndrome in aging men, consists of physical, sexual, and psychologic symptoms that include weakness, fatigue, reduced muscle and bone mass, impaired hematopoiesis, oligospermia, sexual dysfunction, depression, anxiety, irritability, insomnia, memory impairment, and reduced cognitive function. Free testosterone levels begin to decline at a rate of 1% per year after age 40 years. It is estimated that 20% of men aged 60-80 years have levels below the lower limit of normal. Although the causal relationship between declining testosterone levels and development of andropause symptoms is not firmly established, administration of testosterone to this population resulted in improvements in many areas. Most studies to date focused on physical benefits of testosterone replacement and failed to assess psychologic symptoms rigorously. Preliminary data suggest that therapy may benefit elderly men with new-onset depression. Testosterone administration is not without problems, the most worrisome being the potential for increased prostate cancer risk. Despite this concern, a limited number of studies administered the hormone weekly for up to 2 years, with only mild increases in prostate-specific antigen over control values. Currently, insufficient evidence, primarily regarding psychologic safety and efficacy, exists to warrant general administration of testosterone to elderly hypogonadal men. Further clinical investigations of this therapy in men with low testosterone levels and andropause symptoms are justified and necessary.


Subject(s)
Hormone Replacement Therapy/methods , Testosterone/therapeutic use , Aged , Hormone Replacement Therapy/adverse effects , Hormone Replacement Therapy/psychology , Humans , Male , Middle Aged , Prostatic Neoplasms/chemically induced , Testosterone/adverse effects , Testosterone/physiology
16.
Antimicrob Agents Chemother ; 43(8): 2005-9, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10428927

ABSTRACT

We have previously described the activity of low-dose clindamycin in extended-interval dosing regimens by determination of bactericidal titer in serum. In this study, we used a one-compartment in vitro dynamic infection model to compare the pharmacodynamics of clindamycin in three intravenous-dosing regimens (600 mg every 8 h [q8h], 300 mg q8h, and 300 mg q12h) against three clinical isolates of Staphylococcus aureus and two clinical isolates of Streptococcus pneumoniae. Test organisms were added to the central compartment of the model to yield a starting inoculum of 10(6) CFU/ml. Clindamycin was injected as a bolus into the central compartment at appropriate times over 48 h to simulate the q8h or q12h dosing regimens. Drug-free culture medium was then pumped through the system to mimic a half-life of 2.4 h. At predetermined time points during the experiment, samples were removed from the central compartments for colony count determination and drug concentration analysis. The rates of killing did not significantly differ among the three clindamycin dosing regimens against either S. aureus or S. pneumoniae (P = 0.88 or 0.998, respectively). Likewise, no significant differences in activities were detected among the three regimens against staphylococci (P = 0.677 and 0.667) or pneumococci (P = 0.88 and 0.99). Against an S. aureus isolate exhibiting inducible macrolide-lincosamide-streptogramin B resistance, none of the three clindamycin regimens prevented regrowth of the resistance phenotype in the model. In this model, clindamycin administered at a low dose in an extended-interval regimen (300 mg q12h) exhibited antibacterial activity equivalent to that of the 300- or 600-mg-q8h regimen.


Subject(s)
Anti-Bacterial Agents/pharmacology , Clindamycin/pharmacology , Pneumococcal Infections/drug therapy , Staphylococcal Infections/drug therapy , Staphylococcus aureus/drug effects , Streptococcus pneumoniae/drug effects , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/pharmacokinetics , Clindamycin/administration & dosage , Clindamycin/pharmacokinetics , Dose-Response Relationship, Drug , Drug Administration Schedule , Humans , Microbial Sensitivity Tests , Models, Biological , Pneumococcal Infections/metabolism , Pneumococcal Infections/microbiology , Staphylococcal Infections/metabolism , Staphylococcal Infections/microbiology , Staphylococcus aureus/isolation & purification , Streptococcus pneumoniae/isolation & purification
17.
Am J Health Syst Pharm ; 55(19): 1987-94, 1998 Oct 01.
Article in English | MEDLINE | ID: mdl-9784785

ABSTRACT

The epidemiology, resistance mechanisms, susceptibility testing, treatment, prevention, and clinical importance of penicillin-resistant Streptococcus pneumoniae (PRSP) infection are discussed. PRSP is an established presence in the United States, with some geographic areas reporting decreased susceptibility in up to half of isolates. The mechanism of resistance to beta-lactam antibiotics in S. pneumoniae is genetic changes resulting in decreased binding of drug to the bacterial cell wall. Emerging PRSP strains have necessitated testing as a tool in selecting drugs for treating life-threatening infections. Opinions differ on how to treat these infections empirically. Non-life-threatening infections, such as otitis media, are still often treated successfully with amoxicillin, amoxicillin-clavulanate potassium, or a third-generation cephalosporin. Currently recommended initial treatment of pneumococcal pneumonia in otherwise healthy patients requiring hospitalization consists of cefuroxime, ceftriaxone, or cefotaxime; some authors continue to emphasize injectable penicillin. Once the mainstay of empirical treatment of pneumococcal meningitis, penicillin has largely been abandoned in favor of cefotaxime or ceftriaxone. Vaccination remains an underutilized strategy in atrisk populations. The clinical importance of penicillin resistance among pneumococci is still uncertain. Changing patterns in the susceptibility of S. pneumoniae to penicillin make selection of appropriate therapy increasingly difficult. Key considerations are the site of infection and the level of resistance.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Penicillin Resistance , Pneumococcal Infections/drug therapy , Streptococcus pneumoniae/drug effects , Anti-Bacterial Agents/pharmacology , Humans , Pneumococcal Infections/epidemiology , Pneumococcal Infections/microbiology , Pneumococcal Infections/prevention & control , Vaccination
18.
Antimicrob Agents Chemother ; 42(6): 1382-6, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9624480

ABSTRACT

We evaluated the pharmacodynamic activities of fluconazole and amphotericin B given alone and in combination against Candida albicans by using an in vitro model of bloodstream infection that simulates human serum pharmacokinetic parameters for these antifungals. Fluconazole was administered as a bolus into the model to simulate regimens of 200 mg every 24 h (q24 h) and 400 mg q24 h. Amphotericin B was administered at doses producing the peak concentration (2.4 micrograms/ml) observed with a regimen of 1 mg/kg of body weight q24 h. A combination regimen of fluconazole (400 mg q24 h) and amphotericin B (1 mg/kg q24 h) administered simultaneously and as a staggered regimen (amphotericin B bolus given 8 h after fluconazole bolus) was also simulated in the model to characterize possible antagonism between these agents. Fluconazole alone and amphotericin B alone demonstrated fungistatic (< 99.9% reduction in numbers of CFU per milliliter from the starting inoculum) and fungicidal (> 99.9% reduction) activity, respectively. When fluconazole and amphotericin B were administered simultaneously, fungicidal activity similar to that observed with amphotericin B alone was observed. Staggered administration of fluconazole and amphotericin B, however, resulted in a substantial reduction of the fungicidal activity of amphotericin B, producing fungistatic activity similar to that observed with noncombination fluconazole regimens. These results demonstrate the usefulness of this model for comparing the in vitro pharmacodynamic characteristics of different antifungal regimens and support the theory of azole-polyene antagonism. The effects of this antagonism on the in vivo activity and clinical usefulness of combination antifungal therapy, however, remain to be determined.


Subject(s)
Amphotericin B/pharmacology , Antifungal Agents/pharmacology , Candida albicans/drug effects , Fluconazole/pharmacology , Amphotericin B/administration & dosage , Amphotericin B/pharmacokinetics , Antifungal Agents/administration & dosage , Antifungal Agents/pharmacokinetics , Candida albicans/metabolism , Fluconazole/administration & dosage , Fluconazole/pharmacokinetics , Microbial Sensitivity Tests
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