Gas chromatographic screening procedures have been evaluated which permit the detection of stimulants and sedatives in blood after administration of pharmacological doses. The techniques actually used in sample preparations and gas chromatographic work are presented as well as examples of pharmacokinetic studies and postive dope cases. The use of sensitive and selective detectors like the nigrogen-specific detector or a mass spectrometer is absolutely essential for routine work, as for non-specific detectors the number of "false positives" leads to an intolerable work load for the laboratory. (+info)
Increasing maternal blood pressure with ephedrine increases uterine artery blood flow velocity during uterine contraction.
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BACKGROUND: During labor, ephedrine is widely used to prevent or to treat maternal arterial hypotension and restore uterine perfusion pressure to avoid intrapartum fetal asphyxia. However, the effects of ephedrine on uterine blood flow have not been studied during uterine contractions. The purpose of the study was to assess the effects of ephedrine on uterine artery velocities and resistance index using the Doppler technique during the active phase of labor. METHODS: Ten normotensive, healthy parturients with uncomplicated pregnancies at term received intravenous ephedrine during labor to increase mean arterial pressure up to a maximum of 20% above their baseline pressure. Peak systolic and end-diastolic Doppler flow velocities and resistance indices were measured in the uterine artery before and immediately after administration of bolus intravenous ephedrine and after ephedrine washout. Umbilical and fetal middle cerebral arterial resistance indices and fetal heart rate were also calculated. RESULTS: After ephedrine administration, mean arterial pressure increased by 17 +/- 4%. End-diastolic flow velocity in the uterine artery at peak amplitude of uterine contraction was restored to 74% of the value observed in the absence of contraction. The systolic velocity was totally restored, and the uterine resistance index was significantly decreased, compared with the values in the absence of contraction. Between uterine contractions, ephedrine induced similar but less marked effects. Fetal hemodynamic parameters were not altered by ephedrine administration. CONCLUSIONS: Bolus administration of intravenous ephedrine reversed the dramatic decrease in diastolic uteroplacental blood flow velocity and the increase in resistance index during uterine contraction, without altering fetal hemodynamic parameters. This suggests that the increase in uterine perfusion pressure during labor could in part restore uterine blood flow to the placenta during uterine contraction. (+info)
Implementation of the Comprehensive Methamphetamine Control Act of 1996; regulation of pseudoephedrine, phenylpropanolamine, and combination ephedrine drug products and reports of certain transactions to nonregulated persons. Final rule.
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DEA is amending its regulations to implement the requirements of the Comprehensive Methamphetamine Control Act of 1996 (MCA) with respect to the regulation of pseudoephedrine, phenylpropanolamine, and combination ephedrine drug products as List I chemicals, and the reporting of certain transactions involving pseudoephedrine, phenylpropanolamine, and combination ephedrine drug products. The MCA removed the previous exemption from regulation as List I chemicals which had applied to pseudoephedrine, phenylpropanolamine, and combination ephedrine drug products. This action makes persons who distribute the products subject to the registration requirement. Also, distributions, importations, and exportations of the products became subject to the existing chemical controls relating to regulated transactions, except in certain circumstances specified in the MCA. The MCA also requires that reports be submitted for certain distributions involving pseudoephedrine, phenylpropanolamine, and ephedrine (including drug products containing those chemicals) by Postal Service or private or commercial carrier to nonregulated persons. This final rule amends the regulations to make them consistent with the language of the MCA and to establish specific procedures to be followed to satisfy the new reporting requirement. DEA has, where possible, taken action to limit the public impact of these new requirements while remaining consistent with the intent of the MCA to attack the diversion of regulated drug products to the clandestine manufacture of methamphetamine. (+info)
High flow priapism due to an arterial-lacunar fistula complicating initial veno-occlusive priapism.
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High flow or arterial priapism is rare, caused by unregulated arterial blood flow from a lacerated cavernous artery or branch entering directly into lacunar spaces, bypassing the protective, high resistance helicine arterioles and resulting in an arterial-lacunar fistula (ALF) and usually occurs following direct blunt or penetrating perineal trauma. Clinical features include delayed onset of a constant, painless, nontender erection of incomplete rigidity with potential for full rigidity with sexual stimulation. Colour duplex Doppler ultrasonography (CDU) is reliable in the diagnosis of arterial priapism. Treatment by arterial ligation, super-selective embolisation with autologous clot, gelatin sponge or microcoil, duplex guided compression, systemic or intracavernous administration of a variety of alpha-adrenergic agents or methylene blue, mechanical compression/ice packs or expectant management has been reported. (+info)
Modifications of responses to adrenergic drugs in arterial strip by treatment in vivo with ephedrine and reserpine.
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The aim of the present experiment was to investigate effects of ephedrine and reserpine, administered in vivo, on responses of dog isolated arterial strips to adrenergic drugs, and to study a possible mechanism involved in the reversal of blood pressure responses to dopamine. Dose-dependent contractile responses to adrenaline (A), dopamine (DA) and ephedrine (ED) were depressed in the femoral strips isolated from the ED-treated dogs as compared with those isolated from the untreated dogs. Those to noradrenaline (NA) were potentiated in low concentration and in hibited in high concentration, though those to tyramine (TY) were not altered. Relaxing and contractile responses to isoprenaline (IP) were inhibited. DA did not induce a relaxing effect but a contractile one even in the strips brought to a state of moderate tone with ED or phelypressin. In the strips isolated from the reserpine-treated dogs, contractile responses were to some extent potentiated by NA, A and DA, and significantly by ED, while those to TY were inhibited. Relaxing responses to IP were reduced and contractile responses potentiated. In the strips extirpated from the reserpine and ED-treated dogs, contractile responses to NA and A were potentiated in low concentration and tended to be potentiated in high concentration whereas those to DA and ED were not affected. Dose-dependent relaxing effects of DA in the dog renal and mesenteric strips contracted previously by KCl after phenoxybenzamine were attenuated by treatment with ephedrine in vivo. The results suggested that the dopamine reversal in the blood pressure may be mainly due to actions other than its peripheral effect on the blood vessels. (+info)
Pharmacological properties of traditional medicines (XXVII). Interaction between Ephedra Herb and Gypsum under hyperthermal conditions in rats.
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There are many important considerations in the interactions among the herbal constituents in a prescription of traditional Chinese medicine (TCM). Ephedra Herb [Chinese characters: see text] (Eph) is described a warm and acrid agent in TCM. The combination of Eph and Gypsum [Chinese characters: see text] (Eph-Gyp) shows specific actions in patients with different body temperatures. Previous reports suggested that Gypsum prevents the thermogenesis effect induced by ephedrine at an ambient temperature of 22 degrees C. In this investigation, the properties of Eph-Gyp in hyperthermal rats were studied in detail. It was shown that Gypsum Extract (GyE) enhanced the thermogenesis of Eph in hyperthermal rats, although not in normal rats. The results support not only the opposite actions of Eph-GyE but also the clinical differences in the symptomatic patterns of body temperature for Makyo-Kanseki-To [Chinese characters: see text] and Dai-Seiryu-To [Chinese characters: see text]. (+info)
Clinical determinants of ventricular sympathetic reinnervation after orthotopic heart transplantation.
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BACKGROUND: It has been demonstrated that ventricular sympathetic reinnervation after cardiac transplantation improves exercise performance. The extent of reinnervation increases with time but is variable. Little is known about other influencing factors. METHODS AND RESULTS: Seventy-seven nonrejecting transplant recipients were cross-sectionally studied by PET with the catecholamine analogue C-11 hydroxyephedrine at 4.8+/-3.5 years after transplantation. Results were compared with history-derived parameters related to recipient's clinical course before, during, and after surgery; donor characteristics; and immunogenetics. Partial reinnervation was observed in 52 patients (extent, 21+/-16% of left ventricle). Complete denervation was found in 25 patients at various times after transplantation. Reinnervation extent correlated with time after surgery (r=0.387; P<0.001) but also inversely with donor age (r=-0.309, P=0.006) and recipient age (r=-0.243, P=0.032). Maximal hydroxyephedrine retention correlated inversely with frequency of rejection episodes (r=-0.267, P=0.019), was reduced when aortic complications occurred perioperatively (9 patients), and correlated inversely with aortic cross-clamp time (r=-0.331, P=0.006). Other parameters were not associated with reinnervation. Patients were surveyed for clinical complications over >12 months after PET (until 7.3+/-4.2 years after transplantation), but significant effects of reinnervation on outcome were not observed. CONCLUSIONS: The present data suggest that sympathetic reinnervation after cardiac transplantation is not simply a function of time. Reinnervation is more likely with young age, fast and uncomplicated surgery, and low rejection frequency. Despite few effects on prognosis in otherwise healthy recipients, improved understanding of clinical determinants may contribute to enhance allograft reinnervation and thereby augment exercise capacity in the future. (+info)
The acute and chronic bronchodilator effects of ephedrine in asthmatic patients.
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In eight asthmatic patients, there was no change in the bronchodilator response to a single dose of ephedrine (22 mg) given alone or in a compound tablet, after treatment with ephedrine (11 mg three times a day) or one tablet three times a day for 2 weeks. 2 There was no deterioration in lung function during the 2 week treatment period with either ephedrine or the compound tablet. 3 An inter-patient variation was noted in the plasma ephedrine concentraition required for bronchodilatation. 4 The half-life of theophylline did not change after chronic treatment with the tablets, one three times a day for 2 weeks. (+info)