PubMed Health⌕ Search

Biomedical subjects

B L Mirkin

Publications and source records attributed to B L Mirkin.

18 recordsLinked to original sources
PubMed1979

Elimination kinetics of furosemide in perilymph and serum of the chinchilla. Neuropharmacologic correlates.

This study was done to determine the comparative elimination kinetics of furosemide from chinchilla perilymph and serum, and to correlate perilymph concentration with changes in endocochlear potential. The elimination kinetics of furosemide (FU) were determined in sera and perilymph obtained from chinchillas injected with 100 mg/kg i.v. of FU. Concentrations of FU exhibited a linear decay pattern in serum and perilymph over the initial 60 minutes. The rate of decline of furosemide levels in perilymph was about four times slower than the rate of fall in serum. Chronic treatment (25 mg/kg i.p. every 12 hours) did not appear to influence the level of drug at 60 minutes after a dose of FU (100 mg/kg IV). Chinchillas were also studied following doses of FU ranging from 25--200 mg/kg i.v. to see the effect on endocochlear potential (EP). A positive correlation was found between FU dosage, the maximum millivolt reduction of EP and the time to initiation of recovery of EP. The perilymph concentration of furosemide when the EP began to recover was 5 microgram/ml (1.5 x 10(-5) M). Knowledge of furosemide kinetics may ultimately be applied to prevent ototoxicity in patients.

Animals↗
PubMed1978

Relation between plasma and red-cell electrolyte concentrations and digoxin levels in children.

We determined alterations in plasma and red-cell electrolyte concentrations associated with digoxin administration in 11 children in heart failure, 24 nontoxic patients receiving maintenance digoxin and 11 children in whom digoxin toxicity developed. Twenty normal children served as controls. Digoxin therapy was associated with a mean (+/- S.E.M.) increase in red-cell sodium from a pretreatment level of 6.2 +/- 0.7 meq per liter to 11.9 +/- 1.2 meq per liter and a decrease in red-cell potassium from 105.4 +/- 1.4 to 99.5 +/- 1.9 meq per liter (P less than 0.001). The red-cell sodium levels of toxic patients exceeded those of nontoxic patients whereas the potassium concentrations were lower (P less than 0.001). Toxic patients manifested significantly higher ratios of red-cell sodium to red-cell potassium (0.213 +/- 0.003) than nontoxic patients (0.085 +/- 0.008; P less than 0.001). Changes in red-cell electrolytes are sensitive indicators of digoxin affects.

Adolescent↗
PubMed1978

Age dependant factors influencing digoxin pharmacokinetics in the postnatal puppy.

H3-digoxin pharmacokinetics following intravenous pulse injections was studied in dogs ranging in age from 0.5--2 days (n=2), 3--10 days (n=6), 11--30 days (n=5), 31--90 days (n=3) and adult dogs (n=5). All animals in each age group exhibited a biexponential elimination of H3-digoxin from the vascular compartment and data are analyzed by use of a two compartment pharmacokinetic model. Pharmacokinetic parameters showed significant age related differences. The mean T1/2(alpha) was greater in puppies aged 0.5--2 (8.92 +/- 2.61 min), 3--10 (11.8 +/- 1.99 min) and 11--30 days (10.32 +/- 1.89 min) when compared to adult dogs (5.36 +/- 0.91 min). The mean T1/2(beta) was four times longer in 3--10 day old dogs (1342.05 min) than in adult dogs (327.0 min) and decreased with increasing age of the puppies. The beta-phase rate constants were statistically different (p less than 0.05) between 3--10 day old and adult dogs. Elimination of H3-digoxin was slower in puppies than adult dogs (Kel in 3--10 day old puppies = 0.0046 min(-1); adult dogs = 0.0197 min(-1)) and was accompanied by a lower clearance of H3-digoxin in 3--10 day old puppies (2.05 ml/min/kg) than in adult dogs (7.41 ml/min/kg) [p less than 0.0001]. Functional immaturity of the canine kidney during early development probably constitutes the physiologic basis for the differences noted in H3-digoxin kinetics. While these distinctions in elimination kinetics are age related they do not clarify why younger organisms tolerate higher digoxin levels than adults with less apparent toxicity.

Age Factors↗
PubMed1977

Management of severe childhood hypertension with minoxidil: a controlled clinical study.

The therapeutic efficacy of four antihypertensive regimens (minoxidil, propranolol, and hydrochlorothiazide; propranolol and hydrochlorothiazide; methyldopa and hydroch-orothiazide; and hydrochlorothiazide alone) was evaluated in one child with systolic hypertension and in eight children with systolic and diastolic hypertension. The mean blood pressure of 148/98+/-8/4 mm Hg observed during the hydrochlorothiazide control period fell to 142/88+/-8/4 mm Hg following methyldopa and hydrochlorothiazide, 141/85+/-6/2 mm Hg following propranolol and hydrochlorothiazide, and 128/74+/-4/2 mm Hg following minoxidil, propranolol, and hydrochlorothiazide. The only side effect directly associated with administration of minoxidil was hypertrichosis. The effectiveness of minoxidil in the present study suggests that this drug offers an important adjunct to current antihypertensive therapy in children.

Adolescent↗