PubMed Health⌕ Search

Biomedical subjects

R E Altman

Publications and source records attributed to R E Altman.

5 recordsLinked to original sources
PubMed1990

Evaluation of a rapid method for measuring theophylline in a clinical setting.

The need to determine rapidly the theophylline levels of patients in ambulatory settings such as family practice offices has led to the development of instruments purported to be fast, reliable, and cost-effective. This study evaluated one such instrument, the Ames Seralyzer, and compared the findings with those of the Du Pont aca. Forty-six patient samples were split and run on both instruments by trained laboratory personnel. Validation studies yielded a correlation coefficient of r = .9680 (N = 46). Precision assays showed the 27.5 and 82.5 mumol/L (5 and 15 mg/L) levels of theophylline found in control samples produced day-to-day coefficients of variation of 8.8% (n = 43) and 5.8% (n = 35), respectively. After initial evaluation of the Seralyzer, duplicate assays were performed because of erratic results. The evaluators felt that a major source of error was in the diluting and pipetting steps involved in the procedure. The Seralyzer was easy to run but did require some technique-dependent skills.

Ambulatory Care↗
PubMed1988

Clinical and pharmacokinetic evaluation of a sustained-release liquid theophylline preparation.

Theolan Suspension is the first long-acting liquid theophylline dosage form. A crossover study comparing the pharmacokinetic and clinical response to Theolan Suspension (administered every 12 hours) with aminophylline solution (administered every 8 hours) in children younger than 12 years of age is reported. Twenty-seven patients completed the study: 17 children were aged 6 years or younger and five patients were 3 years or younger. All patients were withdrawn from bronchodilator therapy and then were titrated to clinically effective doses of study medication. There was an equivalent and significant reduction from baseline levels in the mean symptom score during administration of theophylline suspension (42%; p less than or equal to 0.001) and aminophylline solution (57%; p less than or equal to 0.001). Mean values for FEV1 (1.2 versus 1.3 L), FEV1/FVC (77% versus 79%), and reduction in acute metaproterenol use (24% versus 43%) in children receiving theophylline suspension and aminophylline solution revealed no differences between products. Adverse effects were reported more frequently for the aminophylline solution, possibly caused in part to its taste. Of children stating a taste preference, eight of 10 children chose the Theolan Suspension. The suspension demonstrated a lower peak theophylline blood level at a later time (11.6 micrograms/ml at 3 1/2 hours), compared to the solution (14.6 micrograms/ml at 1 1/2 hours; p less than or equal to 0.01). Indexes of theophylline fluctuation during the dosing interval indicated equivalent or reduced variability for the suspension. Relative bioavailability of theophylline suspension was 89% of that for the solution.(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma↗
PubMed1988

Neonatal withdrawal symptoms after chronic maternal ingestion of caffeine.

We have identified eight infants born to mothers who were heavy users of caffeine during pregnancy. These infants exhibited unusual behavior in the immediate newborn period. Predominant symptoms were irritability, jitteriness, and vomiting. The eight infants had extensive diagnostic studies and none of the usual causes for their symptoms were identified. Caffeine was present in the serum of six infants, and three of the six infants had caffeine in their urine. The symptoms resolved spontaneously. We hypothesize that these infants were exposed to high maternal levels of caffeine for the majority of the pregnancy, resulting in a withdrawal syndrome after delivery.

Bradycardia↗
PubMed1988

Recovery of phenytoin from solutions of caseinate salts and calcium chloride.

The recovery of phenytoin from solutions of intact protein components of enteral nutrition products was studied. Diluted phenytoin oral suspension was added to 10 1-mL samples of solutions of sodium caseinate, calcium caseinate, a mixture of sodium and calcium caseinates, and calcium chloride as well as to 10 1-mL samples of a distilled water control to produce theoretical concentrations of 10 micrograms/mL. The samples were filtered using an ultrafiltration technique and assayed for phenytoin concentration by high-performance liquid chromatography. The mean concentration of phenytoin in the filtrates of the test samples was significantly lower than the mean concentration in the control samples. The recovery of phenytoin from sodium caseinate solutions was significantly lower than that from solutions of calcium caseinate or calcium chloride. There was no significant difference between recovery of phenytoin from sodium caseinate solutions and that from solutions of sodium and calcium caseinates. Decreased phenytoin absorption from enteral nutrient solutions in vitro may be associated with the presence of caseinate salts and calcium chloride. However, this relationship cannot be extrapolated to in vivo absorption.

Calcium Chloride↗