ABSTRACT
Atropine is used both to treat a variety of clinical disorders and as an antidote to cholinesterase poisoning. While various conditions affect the physiologic responses to atropine, little is known of the pharmacokinetics of this drug except under resting conditions. Pharmacokinetic studies were performed in mongrel dogs under two experimental conditions, moderate hemorrhage and hypothyroidism, to determine whether im absorption and elimination of atropine (0.05 mg/kg body weight) were affected by changes in hemodynamic or metabolic status. Using a randomized, crossover experimental design, it was found that during hypovolemia the mean volume of distribution was reduced by 22% (2.50 +/- 0.62 vs. 3.21 +/- 0.63 L/kg), with no changes in peak serum level, total atropine availability, elimination half-life, or whole-body clearance. Hypothyroidism was associated with a significant increase in peak serum atropine concentration (26.4 +/- 3.9 vs. 20.6 +/- 4.9 ng/ml) and drug bioavailability (48.5 +/- 8.8 vs. 30.0 +/- 10.7 ng/ml.h), while the clearance was reduced by 39% (426 +/- 34 vs. 696 +/- 187 ng/ml.min). These results suggest that atropine kinetics are not altered appreciably during moderate hemorrhage. In hypothyroidism, alterations in atropine pharmacokinetics may warrant modification of drug dose and frequency of administration.
Subject(s)
Atropine/pharmacokinetics , Hemorrhage/metabolism , Hypothyroidism/metabolism , Animals , Atropine/blood , Dogs , Half-Life , Male , Metabolic Clearance Rate , RadioimmunoassayABSTRACT
Among 34 patients with vascular rings, symptoms of tracheal and esophageal compression or both occurred during the first six months of life in 24 (71%). Diagnosis was made in all cases on either plain x-ray film or esophagogram, and was confirmed by operation or angiogram. Associated defects were numerous, with ventricular septal defect (5) and Down's syndrome (3) most common. Operative intervention was required in 18 cases (53%), including 12 of the 14 double arches. Only one of the ten patients with symptomatic recurrent subclavian artery underwent operation. Fourteen of the 18 patients operated upon had early total relief of symptoms, and 17 had excellent late results. A simple system for describing the embryology of vascular rings is presented, and the embryologic relationship between vascular rings and interrupted aortic arches is described. Because of frequent delay in recognition of vascular rings and other surgically correctable lesions, the work-up of every child with two or more episodes of pneumonia should include barium swallow.
Subject(s)
Aorta, Thoracic/abnormalities , Aorta, Thoracic/embryology , Adolescent , Aorta, Thoracic/surgery , Brachiocephalic Trunk/embryology , Child , Child, Preschool , Humans , Infant , Infant, Newborn , Subclavian Artery/embryologyABSTRACT
The authors describe a case with sciatic pain caused by a large extrapelvic aneurysm of the inferior gluteal artery. Differential diagnosis and treatment are discussed.