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Biomedical subjects

R L Sprague

Publications and source records attributed to R L Sprague.

At least 55 records · Page 3Linked to original sources
PubMed1977

Methylphenidate in hyperkinetic children: differences in dose effects on learning and social behavior.

Methylphenidate (Ritalin) is widely prescribed for hyperkinetic children. This study showed a peak enchancement of learning in children after being given a dose of 0.3 milligram per kilogram of body weight, and a decrement in learning in those given larger doses; social behavior showed the most improvement in children given 1.0 milligram per kilogram. These results had been hypothesized from theoretical dose-response curves which indicate different target behaviors would improve at different doses.

Child↗
PubMed1976

Cardiovascular responses of hyperactive children to methylphenidate.

Heart rate, blood pressure, and oxygen consumption were measured in 27 hyperactive children during rest, exercise, and recovery, once taking placebo and again taking methylphenidate hydrochloride. Half were measured first taking the drug and half first taking the placebo. Twenty-three matched controls were also measured twice to test for reproducibility of results. Drug and placebo ECGs were recorded on 12 of the subjects. Oxygen consumption did not change (P = .40), but heart rate (P = .001) and blood pressure (P = .003) increased significantly with methylphenidate therapy. There was a significant correlation between size of dose in milligrams per kilogram and increase in heart rate (.38, P less than .05) and blood pressure (.50, P less than .05 systolic) (.46, P less than .05 diastolic). No evidence of the development of tolerance to these drug effects was found in children who had been taking methylphenidate from two months to more than a year. No ECG changes other than tachycardia were seen.

Age Factors↗
PubMed1975

A reproducible gas chromatographic mass spectrometric assay for low levels of methylphenidate and ritalinic acid in blood and urine.

A rapid, sensitive method of analysis for methylphenidate and ritalinic acid in blood and urine has been developed using gas chromatography mass spectrometry and selected ion monitoring for separation and detection. The methylphenidate is isolated by solvent extraction into chloroform and the ritalinic acid is isolated by salting out into isopropyl alcohol, followed by methylation and subsequent solvent extraction. The method has been applied to the study of methylphenidate metabolism and excretion in adults and hyperactive children undergoing treatment with methylphenidate.

Adult↗
PubMed1975

Conners' Teacher Rating Scale for use in drug studies with children--an empirical study.

Their classroom teachers rated 291 schoolchildren, grades kindergarten through 6, on Conners' Teacher Rating Scale, developed for and used widely in drug studies in children. Scores were found to be significantly lower than those reported for a similar group of 92 New York children and considerably less than those of a group of 64 children receiving medication for deviant behavior. Boys generally had higher scores for acting-out-type behavior while girls scored higher on neuroticism. The factor structure in this sample showed some differences from that in Conners' original analysis but they are insufficient for any change in the widely accepted scoring system, except perhaps to add a fifth factor of sociability.

Acting Out↗
PubMed1975

The influences of methylphenidate on heart rate and behavioral measures of attention in hyperactive children.

Reaction-time performance and heart-rate responses associated with attention were used to assess the hyperactive child's attentional deficit and his response to methylphenidate. Attentional deficits shown by long response latencies were reflected in heart-rate responses theoretically incompatible with sustained attention. Subjects exhibiting the greatest attentional deficit displayed the most favorable response to methylphenidate in both reaction-time performance and physiological measures. However, subjects who showed the greatest improvement in social behavior were those who showed the least improvement in reaction-time performance.

Attention↗