PubMed Health⌕ Search

Biomedical subjects

T H Self

Publications and source records attributed to T H Self.

At least 19 recordsLinked to original sources
PubMed1992

A diagnostic approach to 'difficult' asthma.

When patients with asthma do not respond adequately to standard treatment, they are said to have "difficult" asthma. These patients require a lot of healthcare resources, are usually receiving long-term oral corticosteroid therapy, and are significantly sicker than other asthma patients, with attendant increases in morbidity and mortality. In these patients, the management areas summarized in table 1 should be fully explored to determine whether asthma is the correct diagnosis and whether the best care is being given.

Adrenal Cortex Hormones↗
PubMed1992

Correct use of metered-dose inhalers and spacer devices.

In addition to prescribing an appropriate drug regimen, physicians must carefully educate asthmatic patients. For 10 million such patients in the United States as well as millions more around the world, successful education is critical to quality of life and can save lives. Responsible patients who understand that asthma attacks are preventable and who use their medications correctly usually have a gratifying response to treatment. Of special importance is the optimal use of aerosolized drugs, most often given by a metered-dose inhaler plus spacer device.

Aerosols↗
PubMed1992

Two- and four-day rifampin chemoprophylaxis regimens induce oxidative metabolism.

The effects of two short-term chemoprophylaxis regimens of rifampin (2 or 4 days) on oxidative metabolism were investigated in 14 healthy subjects. Seven subjects received 600 mg of rifampin twice daily on study days 6 and 7 (group A), and seven subjects received 600 mg of rifampin once daily on days 4, 5, 6, and 7 (group B). Antipyrine (18 mg/kg of body weight) was administered orally on days 1, 8, and 15. Short-term rifampin regimens increased oral clearance of antipyrine in both groups compared with the baseline value (P less than 0.05), and group B displayed a larger percent increase over the baseline value than group A did (70.5 +/- 14.3 versus 33.1 +/- 18.1; P less than 0.05). The partial metabolic clearance (CLM) of antipyrine to 3-hydroxymethylantipyrine (HMA) on day 8 increased 71 and 108% for regimens A and B, respectively (P less than 0.05 for both). The corresponding increases in CLM to norantipyrine (NORA) were 57 and 98% (P less than 0.05 for both). CLM to 4-hydroxyantipyrine (OHA) on day 8 increased 64% for regimen A (P = 0.08) and 97% for regimen B (P less than 0.05) compared with the baseline. Although CLM to HMA and OHA on day 15 remained greater than 50% over the baseline with both regimens, CLM to NORA on day 15 was less than 25% over the baseline with both regimens. Thus, both short-term rifampin chemoprophylaxis regimens increased antipyrine clearance for at least 1 week. The increase tended to be higher with the 4-day regimen. The pattern observed for the CLMS suggests that more than one P-450 enzyme is affected.

Administration, Oral↗
PubMed1992

Update on rifampin drug interactions. II.

Rifampin is a potent inducer of hepatic P450 oxidative enzymes. Clinically important drug interactions have been documented between rifampin and numerous other drugs, such as oral anticoagulants, oral contraceptives, cyclosporine, digitalis, and ketoconazole. New, potentially clinically significant rifampin drug interactions have been reported for haloperidol, several antiarrhythmics, fluconazole, diltiazem, and select benzodiazepines. Further research has been conducted for previously reported drug interactions with rifampin involving such drugs as glucocorticoids, cyclosporine, verapamil, and oral anticoagulants. Proper management of these interactions is essential to avoid therapeutic failures on initiating rifampin therapy and potential toxic reactions after discontinuing rifampin. New rifampin drug interactions will continue to be identified with future investigations.

Drug Interactions↗
PubMed1991

Drug interaction.

Explore the source record for details and available documents.

Ciprofloxacin↗
PubMed1990

Effects of calcium channel blockers on the pharmacokinetics of propranolol stereoisomers.

Diltiazem and verapamil inhibit oxidative drug metabolism both in vivo and in vitro. We compared their effects on the stereoselective pharmacokinetics and protein binding of propranolol in 12 subjects. After 6 days of coadministration with racemic propranolol, diltiazem caused decreases of 27% and 24% in d-propranolol and 1-propranolol oral clearances, respectively (p less than 0.05 versus control). With verapamil, d-propranolol oral clearance decreased 32% (p less than 0.05), and 1-propranolol oral clearance decreased 26% (p less than 0.05). The unbound fraction of d-propranolol was higher than that of 1-propranolol (p less than 0.05), but the protein binding was not altered by diltiazem or verapamil. Both drugs therefore decreased the unbound oral clearance of each propranolol enantiomer (p less than 0.05). Verapamil caused a stereoselective effect and increased the d/l ratio of propranolol serum concentrations (p less than 0.05) and decreased the d/l ratio of oral clearance (p less than 0.05).

Adult↗
PubMed1990

Evaluation of pharmacists' practice in patient education when dispensing a metered-dose inhaler.

Improper inhalation technique with beta-agonist metered-dose inhalers (MDIs) decreases efficacy of the bronchodilator. The success of demonstrating the correct technique and the pharmacist's role in patient education has been reported. To obtain information regarding the routine patient education practice of pharmacists when dispensing a beta-agonist MDI (albuterol), the following study was performed. Fifty-two prescriptions for an albuterol MDI were presented to 52 randomly chosen community pharmacists in three Tennessee cities. Twenty-six independent and 26 chain pharmacies wer evaluated. Pharmacists' practice with regard to patient education, instruction, and demonstration of the correct usage of the MDI was observed and recorded. Overall, 13 percent of the pharmacists initially offered to educate the patient-investigator (PI) regarding the correct usage of the MDI without being asked for information. Fifty-three percent of pharmacists offered information only upon being asked specifically how to use the MDI. Of the pharmacists who offered to educate the PI, 71 percent discussed less than half of the eight steps correctly. Only 1 of the 52 pharmacists actually demonstrated MDI inhalation technique, and this in response to a request. No pharmacist asked the PI to perform the technique while he/she observed. No pharmacist offered information on delivery enhancement devices. Our results demonstrate that few pharmacists educate patients on the correct usage of an MDI, and that many pharmacists are not aware of the correct technique.

Evaluation Studies as Topic↗
PubMed1990

Inhaled albuterol and oral prednisone therapy in hospitalized adult asthmatics. Does aminophylline add any benefit?

STUDY OBJECTIVE: To determine the efficacy of intravenous aminophylline in the treatment of adult patients hospitalized for exacerbation of asthma. DESIGN: Randomized, double-blind, placebo-controlled trial throughout the study. SETTING: University Hospital Clinical Research Center. PATIENTS: Forty-four patients admitted from the emergency room with a primary diagnosis asthma; 39 patients completed the study. INTERVENTIONS: Patients received either intravenous aminophylline or placebo in addition to frequent nebulized albuterol; prednisone 0.5 mg/kg body weight every 6 h orally; and supplemental oxygen. Aminophylline infusion rates were adjusted to achieve serum theophylline concentrations of 10 to 20 micrograms/ml. Changes were made in placebo infusion rates to maintain the double blind design. MEASUREMENTS AND RESULTS: Forced expiratory volume in 1 s (FEV1) and other spirometric measurements every 8 h by a blinded investigator or trained respiratory therapist. Subjective patient response and duration of hospitalization were compared. No difference in spirometric measurements was observed between the two groups at any time point. On admission to the study, FEV1 in the placebo group was 41.5 (+/- 2.9) percent predicted and in the aminophylline group 34.7 (+/- 2.3) percent predicted (p = 0.08). At discharge, FEV1 was 70.4 (+/- 2.9) percent predicted in the placebo group and 63.7 (+/- 2.8) percent predicted in the theophylline group (p = 0.10). There was no difference in subjective patient rating or duration of hospitalization between the two groups (placebo 1.95 days and aminophylline 1.78 days, p = 0.51). CONCLUSIONS: Our results suggest that aminophylline therapy does not add significant benefit to other standard therapies in hospitalized adult asthmatic patients. Because of the risks and cost of aminophylline treatment in the hospital setting, further research is needed to determine if there are subgroups of adult asthmatics who may benefit from the addition of aminophylline to other standard optimal therapies.

Acute Disease↗
PubMed1990

Possible influence of carbamazepine on plasma imipramine concentrations in children with attention deficit hyperactivity disorder.

The effect of carbamazepine on the plasma concentration of imipramine and its metabolite desipramine was examined retrospectively in 36 sex- and age-matched children with attention deficit hyperactivity disorder. One-half of the children received imipramine and the other half received combined carbamazepine and imipramine for 1-6 months. The imipramine dosage was significantly higher in the combined treatment group than in the imipramine-only group. Despite receiving larger doses, the combined treatment group had significantly lower mean levels of imipramine, desipramine, and total tricyclic antidepressant compared with those children receiving imipramine alone. Lowered plasma concentrations of tricyclic antidepressants with carbamazepine coadministration have not been reported previously. Although more rigorous studies are needed to confirm these findings, our data suggest that increased imipramine doses may be necessary for adequate response in children on combined therapy. Moreover, toxicity could result upon withdrawal without imipramine dosage adjustment.

Adolescent↗
PubMed1989

Is theophylline use justified in acute exacerbations of asthma?

Despite widespread use of theophylline in the hospital management of asthma, supportive data justifying its use are sparse. Clinical research in the 1980s has forced a serious new examination of the drug's role in acute exacerbations of asthma. Because of the morbidity, mortality, questionable value, and overall cost of theophylline therapy, this reevaluation is of particular importance. Enhanced knowledge of the value of treatment with intensive inhaled beta agonists, systemic glucocorticoids, and inhaled ipratropium should prompt elimination of the routine, initial use of theophylline in emergency room care of most asthmatics. Further research is necessary to justify the routine, initial use of the drug in hospitalized asthmatics.

Acute Disease↗
PubMed1989

Hypothyroidism: effect on warfarin anticoagulation.

Although our observation is not the first case of reduced PT response to oral anticoagulants associated with hypothyroidism, it is the only such interaction reported since 1963, and the first case involving warfarin therapy in a human being. We submit this case as a reminder of a potentially forgotten interaction, and to stress the importance of close monitoring in patients receiving warfarin therapy who have concomitant changes in thyroid function.

Administration, Oral↗