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Biomedical subjects

Timothy H Self

Publications and source records attributed to Timothy H Self.

13 recordsLinked to original sources
PubMed2006

Hydralazine-induced lupus: maintaining vigilance with increased use in patients with heart failure.

OBJECTIVE: To review data concerning the incidence and danger of hydralazine-induced systemic lupus erythematosus (SLE) and review how best to monitor patients placed on chronic hydralazine therapy. DATA SOURCES: Literature was sought utilizing PUBMED (1960 to present) and MEDLINE (1966 to present). Search terms included hydralazine, drug-induced systemic lupus erythematosus, congestive heart failure, and antinuclear antibody. DATA SYNTHESIS: A major adverse effect of hydralazine therapy is drug-induced SLE. An evaluation of case reports and review of the literature was undertaken to determine the significance of this major adverse effect and stress the importance of close monitoring of patients placed on chronic hydralazine therapy for heart failure. Risk factors are discussed including high daily doses, slow acetylator and HLA-DRw4 phenotypes, therapy longer than 3 months, and female gender. CONCLUSIONS: Following the publication of A-HeFT, an increase in the amount of hydralazine prescribed in patients with heart failure has been noted. Patients should be closely monitored when initiating hydralazine and during chronic therapy. Although dose limitation of hydralazine reduces risk, low doses are well documented to be associated with SLE. A baseline antinuclear antibody level should be determined on initiation of hydralazine, but it is not recommended to regularly check antinuclear antibody levels because a positive result does not necessarily indicate SLE is present. Patients should be monitored at each visit for signs and symptoms of SLE, and, if any signs and symptoms of the syndrome develop while the patient is on hydralazine therapy, the drug should be discontinued immediately because complications from the syndrome can be potentially fatal.

Heart Failure↗
PubMed2006

Does heart failure exacerbation increase response to warfarin? A critical review of the literature.

BACKGROUND: Numerous factors, such as other drugs, diet, and age, are well documented as altering response to warfarin. Less attention has been focused on the effect of disease states on the response to oral anticoagulants. Decompensated heart failure is reported to increase response to warfarin, but documentation is limited. OBJECTIVE: The purpose of this review is to critically examine the evidence of a possible effect of heart failure exacerbations on response to warfarin. RESEARCH DESIGN AND METHODS: A literature search was completed of the last 60 years using several databases, including PubMed, MEDLINE, EMBASE, and SCOPUS. Key terms in our search included 'warfarin' AND 'heart failure' and 'heart failure exacerbation' (or 'decompensated heart failure') AND 'effect on warfarin'. When relevant citations were found, the references cited by those authors were checked. RESULTS: Several reports from 1946-1989 suggested that decompensated heart failure increases response to oral anticoagulants. Unfortunately, these early reports have important limitations. More recent reports, since the widespread use of the international normalized ratio (INR), also suggest that heart failure exacerbations are associated with increased response to warfarin. Patient populations are small in these reports. CONCLUSIONS: Heart failure exacerbations may be associated with an increased response to warfarin and other vitamin K antagonists, but many reports are inadequate, and it appears that not all patients are susceptible to this effect. More frequent monitoring of INR in patients with decompensated heart failure is warranted. It is prudent to initiate warfarin at lower doses in patients with a history of heart failure and to monitor INR every 1-2 weeks during times of instability in ambulatory patients, and daily INRs in hospitalized patients. Given the large number of variables that impact on warfarin dose requirement, it is difficult to clearly establish the effect of decompensated heart failure on response to warfarin. Further studies must take all of these variables into account.

Anticoagulants↗
PubMed2005

Reducing emergency department visits and hospitalizations in African American and Hispanic patients with asthma: a 15-year review.

Minority populations in the United States continue to experience a disproportionate share of emergency department (ED) visits and hospitalizations due to asthma. This review examines programs that have attempted to reduce these acute care visits in African American and Hispanic patients. We performed a PubMed search of the English literature for studies published from March 1990 to March 2005, aimed at reducing ED visits and hospitalizations in patients with asthma. Decreased acute care visits in African American and Hispanic patients with asthma have been demonstrated in several studies over the past 15 years, including collaboration by physicians, nurses, and clinical pharmacists in achieving this goal. These studies have shown that reduced acute care visits are associated with optimal drug therapy per national guidelines, concurrent with patient education, environmental control, and objective monitoring of this inflammatory airway disease. Early intensive patient education was a key feature of these successful programs. Written action plans, including early use of oral corticosteroids at home, and rapport with patients are other key components of programs that have resulted in a decrease in ED visits and hospitalizations.

Adult↗
PubMed2005

Isoniazid hepatotoxicity associated with treatment of latent tuberculosis infection: a 7-year evaluation from a public health tuberculosis clinic.

OBJECTIVES: To determine the overall incidence of isoniazid (INH) hepatotoxicity in a public health tuberculosis clinic over a 7-year period, and to determine if systematic, limited aspartate aminotransferase (AST) monitoring would be of benefit in detecting INH hepatotoxicity. METHODS: Evaluation of INH hepatotoxicity in adults aged > or = 25 years from a database maintained from fall 1996 to 2003 in a public health department clinic. Hepatotoxicity was defined as AST levels more than five times the upper limit of normal (ULN). RESULTS: Among 3,377 patients started on INH therapy, 19 patients had AST levels more than five times the ULN, or a rate of 5.6 per 1,000 patients. Only 1 of 19 patients had prodromal symptoms associated with hepatotoxicity. After 1 month, 3 months, and 6 months of therapy, the numbers of hepatotoxic events per 1,000 patients were 2.75, 7.20, and 4.10. The age-specific numbers of hepatotoxic events per 1,000 patients were 4.40 for those from 25 to 34 years of age, inclusive; 8.54 for those between 35 to 49 years of age, inclusive; and 20.83 for those > or = 50 years old. Age > 49 years (p < 0.02) and baseline AST greater than ULN (p < 0.0003) were risk factors for hepatotoxicity. CONCLUSIONS: Consistent with earlier trials, INH hepatoxicity is age related. Our results suggest hepatotoxicity is also related to baseline AST greater than ULN. Moderate-to-severe hepatotoxicity frequently occurs without symptoms, suggesting the value of more widespread AST monitoring.

Adult↗
PubMed2005

Gender differences in the use of peak flow meters and their effect on peak expiratory flow.

STUDY OBJECTIVE: To determine if gender differences in the skill of using peak flow meters affect peak expiratory flow (PEF). DESIGN: Prospective observational study. SETTING: University classroom. SUBJECTS: One hundred sixteen first-year pharmacy students (76 women, 40 men). INTERVENTION: Students were taught correct use of a peak flow meter by means of classroom discussion and demonstrations. MEASUREMENTS AND MAIN RESULTS: The students' technique in use of the peak flow meter was scored 3 times, and their PEF was recorded. Men scored higher than women (p=0.03) for the steps of "inhale fully" and "exhale as hard and as fast as you can" in the first attempt. Percentage increases in PEF did not significantly differ between the groups. Percentage change in PEF improved from the second attempt to the third attempt in women (p=0.036) but not men. On the third attempt, 13.2% of women versus 2.6% of men had an increase in PEF of more than 50% (p=0.1). CONCLUSION: This study found that men learned the correct technique for using a peak flow meter and attained their best PEF more quickly than women.

Adult↗
PubMed2004

Premenstrual asthma: emphasis on drug therapy options.

Premenstrual asthma is quite common, affecting up to 40% of women. Some studies suggest exacerbations of asthma requiring emergency department visits or hospitalizations are more common in the perimenstrual phase. Several drug treatment modalities for premenstrual asthma have been evaluated. Drug therapies that may be beneficial include leukotriene receptor antagonists, long acting inhaled beta2 agonists, progesterone, estradiol, and gonadotropin-releasing hormone (GnRH) analogs. Further double-blind, randomized, placebo-controlled studies are required before the optimal drug therapy for premenstrual asthma is established.

Adolescent↗
PubMed2003

Efficacy of inhaled corticosteroids administered once daily for asthma.

Inhaled corticosteroids (ICS) are the most effective medications for the long term control of asthma. When first used in asthma management, these drugs were scheduled 3- or 4-times daily, but by the late 1980s, it became clear that most patients respond excellently to twice-daily dosing. Numerous recent double-blind, randomized trials have demonstrated the efficacy of once-daily ICS in the management of pediatric and adult asthma. Once-daily dose ICS is most appropriate for patients' mild persistent asthma, and will be effective for many patients with moderate persistent asthma. Some studies suggest late afternoon/early evening dosing is preferable to single daily dosing in the morning.

Administration, Inhalation↗
PubMed2002

Rifampin and rifabutin drug interactions: an update.

Rifampin is a potent inducer of cytochrome P-450 oxidative enzymes. A few examples of well-documented clinically significant interactions include interactions with warfarin, oral contraceptives, cyclosporine, glucocorticoids, ketoconazole or itraconazole, theophylline, quinidine sulfate, digitoxin or digoxin, verapamil hydrochloride, human immunodeficiency virus-related protease inhibitors, zidovudine, delavirdine mesylate, nifedipine, and midazolam. Recent reports have demonstrated clinically relevant interactions with numerous other drugs, such as buspirone hydrochloride, zolpidem tartrate, simvastatin, propafenone hydrochloride, tacrolimus, ondansetron hydrochloride, and opiates. Rifabutin reduces serum concentrations of antiretroviral agents, but less so than rifampin. To avoid a reduced therapeutic response, therapeutic failure, or toxic reactions when rifampin is added to or discontinued from medication regimens, clinicians need to be cognizant of these interactions. Enhanced knowledge of known interactions will continue to develop, including research on the induction of specific cytochrome P-450 isoenzymes and on the importance of the P-glycoprotein transport system. New rifampin and rifabutin interactions will be discovered with further investigations.

AIDS-Related Opportunistic Infections↗
PubMed2002

Reassessment of theophylline use for severe asthma exacerbation: is it justified in critically ill hospitalized patients?

In the 1990s, numerous double-blind, randomized, placebo-controlled trials revealed that theophylline therapy offered no benefit to inhaled beta2 agonists and systemic corticosteroids in the treatment of patients hospitalized for asthma exacerbations. Routine use of theophylline in patients hospitalized for asthma is no longer advocated due to the potential for serious adverse effects and lack of benefit. However, the question remains whether this drug adds any benefits in critically ill patients who are being admitted to an intensive care unit. Two recent pediatric studies suggest that theophylline therapy may have a role in the management of patients with impending respiratory failure who have failed aggressive treatment with inhaled beta2 agonists, systemic corticosteroids, and inhaled ipratropium. If a patient has failed to respond adequately to high-dose routine therapies, theophylline should be initiated by a clinician who is competent in dosing, monitoring serum concentrations, and assessing factors that modify clearance of this high-risk drug. Further clinical research is needed to verify the value of theophylline in adults and children with severe asthma exacerbations and impending respiratory failure.

Asthma↗
PubMed2002

Lower serum digoxin concentrations in heart failure and reassessment of laboratory report forms.

Serum digoxin concentrations (SDC) have been used clinically since the early 1970s. Whereas the therapeutic range for SDC is frequently cited as either 0.8 to 2.0 ng/mL or 0.5 to 2.0 ng/mL, studies over the past decade suggest an upper limit of 1.0 ng/mL for treating heart failure. The same upper limit for SDC is suggested for patients with heart failure and atrial fibrillation with rapid ventricular response. Reducing the upper limit of the therapeutic range to 1.0 ng/mL on computerized and paper laboratory report forms may guide clinicians to avoid unnecessarily high SDC, thus minimizing risk of digoxin toxicity without sacrificing therapeutic benefit for heart failure.

Anti-Arrhythmia Agents↗
PubMed2002

Fluconazole-carbamazepine interaction.

The patient we describe had elevated carbamazepine serum concentrations during concomitant fluconazole administration (400 mg/day), including serial concentrations both before and after antifungal therapy. Since fluconazole is a known inhibitor of the cytochrome P450 enzyme system, this suggests an inhibition of carbamazepine metabolism.

Adult↗
PubMedDate not supplied

Maintenance asthma treatment with fluticasone/salmeterol combination via Diskus: effect on outcomes in inner-city children enrolled in TennCare.

Although current national guidelines suggest combination inhaled corticosteroid/long-acting inhaled beta2-agonist as the preferred treatment in moderate and severe persistent asthma for children, trials aimed at reducing emergency department (ED) visits and hospitalizations in minority inner-city children have not been conducted with the combination product of fluticasone/salmeterol via Diskus (Advair). This study assessed the effect of fluticasone/salmeterol combination via Diskus therapy on hospitalizations and ED visits in children with asthma. We conducted a prospective 1-year study with an intervention group compared with a usual care control group. This study took place at an inner-city university-affiliated children's medical center allergy clinic. Inner-city patients with asthma aged 4-17 years with a history of frequent ED visits and hospitalizations for the 2 previous years were enrolled beginning in July 2001. A control group of inner-city asthmatic patients was identified via hospital medical records. Patients were prescribed fluticasone/salmeterol combination via Diskus (n = 39) for 1 year and were compared with a usual care control group (n = 39). Although the investigators did not intervene in the control patients, review of their records revealed that all control patients had inhaled corticosteroids prescribed during the intervention period. Outcome measures included ED visits and hospitalizations for 1 year after enrollment versus the mean for acute care visits for 2 years before enrollment in the study. The intervention group had a 20% reduction in ED visits, which was significant compared with the control group (p = 0.017); both groups had significant reductions in hospitalizations. The risk of experiencing an asthma exacerbation (ED visit or hospitalization) was reduced by 33% in the intervention group compared with the control group (risk ratio, 0.67; 95% confidence interval, 0.49-0.90; p = 0.005). Our results suggest that fluticasone/salmeterol combination via Diskus is associated with a reduction in risk of acute exacerbations of asthma in inner-city children, including ED visits and hospitalizations.

Administration, Inhalation↗