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Biomedical subjects

J Barnhill

Publications and source records attributed to J Barnhill.

12 recordsLinked to original sources
PubMed2005

Risperidone half-life in a patient taking paroxetine -- a case report.

This case report further establishes the inhibitory effects of paroxetine on risperidone (R) metabolism in a patient whose R was discontinued due to side effects. Baseline through levels in ng/ml were 33 for R, 9 for 9-hydroxyrisperidone (9-OHR) and 42 for the total moiety. The fourth morning after R discontinuation, levels were 4 for R, 1 for 9-OHR and 5 for the total moiety. The estimated half-lives were 23.8 hours for R, 22.8 hours for 9-OHR and 23.5 hours for the total moiety.

Adult↗
PubMed2000

Extension of a pilot study: impact from the cytochrome P450 2D6 polymorphism on outcome and costs associated with severe mental illness.

The influence of cytochrome P450 2D6 (CYP2D6) genetic variability was examined in psychiatric inpatients by evaluating adverse drug events (ADEs), hospital stays, and total costs over a 1-year period in an extension of a previously published brief report. One hundred consecutive psychiatric patients from Eastern State Hospital in Lexington, Kentucky, were genotyped for CYP2D6 expression. ADEs were evaluated by a neurologic rating scale, modified Udvalg for Kliniske Undersogelser Side Effect Rating Scale, or chart review. Information on total hospitalization days and total costs were gathered for a 1-year period. Forty-five percent of the patients received medications that were primarily dependent on the CYP2D6 enzyme for their elimination. When the analysis was restricted to just those patients in each group receiving medication heavily dependent on the CYP2D6 enzyme, the following were observed: (1) a trend toward greater numbers of ADEs from medications as one moved from the group with ultrarapid CYP2D6 activity (UM) to the group with absent CYP2D6 activity (PM); (2) the cost of treating patients with extremes in CYP2D6 activity (UM and PM) was on average $4,000 to $6,000 per year greater than the cost of treating patients in the efficient metabolizer (EM) and intermediate metabolizer (IM) groups; and (3) total duration of hospital stay was more pronounced for those in CYP2D6 PM group. Variance of hospital stays and costs calculated from these preliminary data suggests that 1,500 to 2,000 patients must be evaluated over at least a 1-year period to determine whether the CYP2D6 genetic variation significantly alters the duration of hospital stay and costs.

Antipsychotic Agents↗
PubMed1999

Tennessee RN first assistant survey data--what types of perioperative education are needed?

Many nursing programs removed perioperative education from their curriculum as early as the late 1960s, and perioperative nursing is now experiencing the consequences. Fewer perioperatively educated graduates are available, the workforce of experienced perioperative nurses is aging, and multiple career opportunities are luring perioperative nurses from the OR and nursing in general. Surveys were conducted in Tennessee to determine the knowledge about perioperative nursing roles and responsibilities. These survey results demonstrate the need for nurses, nursing programs, and hospitals to collaborate in developing guidelines, programs, and evaluation processes based on national perioperative standards.

Adult↗
PubMed1998

Pilot study of the cytochrome P450-2D6 genotype in a psychiatric state hospital.

OBJECTIVE: The authors conducted a pilot study to develop preliminary data on the frequency of cytochrome P450-2D6 (CYP2D6) genotypes in state psychiatric hospital patients and to establish population sizes needed to determine potential clinical relevance in therapeutic outcome. METHOD: One hundred consecutive inpatients at Eastern State Hospital in Kentucky who provided informed consent were genotyped at the CYP2D6 locus during their hospital stay. RESULTS: Twelve of the patients were CYP2D6 deficient, and four carried the *1Xn or *2Xn allele associated with ultrarapid metabolism; all of these patients were Caucasian (N=87). The rate of deficiency in CYP2D6 expression in these Caucasian state psychiatric hospital patients (14%) was twice that of the U.S. population (7%). The patients with CYP2D6 deficiency also appeared more likely to experience side effects in response to CYP2D6 medications. CONCLUSIONS: This study, limited by a small number of subjects, suggests that one-fifth of Caucasians admitted to a state hospital in Kentucky had genotypes associated with extremes in CYP2D6 activity that may have affected their response to CYP2D6 medications.

Adult↗
PubMed1986

Isolated right ventricular infarction: a rare complication of coronary artery dissection.

Infarction of the right ventricle generally occurs in association with posterior left ventricular infarction, and isolated right ventricular infarction is unusual. We have reported a case of acute infarction of the right ventricle unassociated with infarction of the left ventricle in a patient with type I aortic dissection that extended into the right coronary artery, resulting in near-complete occlusion of its lumen. We believe that poor collateral circulation of the myocardium played a major role in the pathogenesis of isolated right ventricular infarction after sudden occlusion of the right coronary artery.

Aortic Dissection↗
PubMed1986

Pharmacokinetic mechanisms of ethanol-psychotropic drug interactions.

Acute and chronic ethanol consumption alters psychotropic drug pharmacokinetics. An understanding of the processes of drug absorption, distribution, biotransformation, and elimination provide a rational basis for predicting and evaluating drug interactions. Careful application of clinical pharmacokinetic models describing these physiological processes are particularly appropriate for the task of understanding drug and alcohol interactions. Absorption: Acute alcohol inhibits first-pass effect increasing systemic bioavailability. Ethanol inhibits gastric emptying and may delay drug absorption (increase lag time of absorption) and decrease the rate of absorption. The effects of chronic alcohol intake are unknown. Distribution: Hypoalbuminemia may be present in alcoholics with liver disease. Fluctuations in free fractions of drugs may occur in the alcohol withdrawal period. The clinical effects of protein binding changes are dependent on degree of binding, hepatic extraction ratio, and binding protein. Acute low-dose ethanol increases hepatic blood flow while high doses decrease it. The effects of chronic alcohol intake on liver blood flow are unknown. Hepatic blood flow changes show the greatest effects on drugs with high extraction ratios. Metabolism: Acute alcohol ingestion usually inhibits drug metabolism and chronic intake (in the absence of severe liver disease) enhances metabolism. Cirrhosis impairs oxidative metabolism, but spares glucuronidation. Although these generalizations may serve as useful guidelines for predicting alcohol and psychotropic drug interactions, they should be applied with caution as exceptions do exist.

Alcoholism↗
PubMed1985

Pharmacokinetic interaction of disulfiram and antidepressants.

Intravenous imipramine and desipramine were administered to two detoxified alcoholics before and during disulfiram treatment. Tricyclic pharmacokinetic parameters, determined from plasma samples over 48 hours, indicated decreased total body clearance, increased elimination half-life, and higher peak plasma levels during disulfiram treatment.

Adult↗
PubMed1984

Enterococcal endocarditis following sigmoidoscopy and mitral valve prolapse.

There is considerable controversy regarding antimicrobial prophylaxis against infective endocarditis for routine sigmoidoscopy without biopsy in patients with underlying valvular heart disease. Sigmoidoscopy is known to produce brief, low-grade bacteremia in some patients. Persons with mitral valve prolapse (MVP) may be at risk of infective endocarditis developing during transient bacteremia. We describe a 67-year-old man with known MVP in whom enterococcal endocarditis developed following routine sigmoidoscopy. We believe this to be the first such reported case.

Aged↗