Synephrine-containing dietary supplement precipitating apical ballooning syndrome in a young female.

Apical ballooning syndrome (ABS) is a unique reversible cardiomyopathy that is frequently precipitated by emotional or physical stress. In addition, the few drugs reported to precipitate ABS were either illegal or strictly controlled for medical use. This paper reports a case of ABS precipitated by a dietary supplement. Our case accentuates the potential risk of dietary supplements containing synephrine, which is uncontrolled and available to the general public. Therefore, the Korea Food and Drug Administration should regulate these dietary supplements, and warn healthcare workers and the general public of the potential hazards of the indiscriminate abuse of dietary supplements.

Synephrine-containing dietary supplement precipitating apical ballooning syndrome in a young female

Apical ballooning syndrome (ABS) is a unique reversible cardiomyopathy that is frequently precipitated by emotional or physical stress. In addition, the few drugs reported to precipitate ABS were either illegal or strictly controlled for medical use. This paper reports a case of ABS precipitated by a dietary supplement. Our case accentuates the potential risk of dietary supplements containing synephrine, which is uncontrolled and available to the general public. Therefore, the Korea Food and Drug Administration should regulate these dietary supplements, and warn healthcare workers and the general public of the potential hazards of the indiscriminate abuse of dietary supplements.

Tachypnea and antipyresis in febrile horses after sedation with alpha-agonists.

BACKGROUND: Signs of tachypnea after sedation of febrile horses with alpha2-agonists have been noted previously but have not been further investigated. OBJECTIVES: To examine the effects of xylazine and detomidine on respiratory rate and rectal temperature in febrile horses and to investigate if either drug would be less likely than the other to cause changes in these variables. ANIMALS: Nine febrile horses and 9 healthy horses were included in the study. METHODS: Horses were randomly assigned to sedation with xylazine 0.5 mg/kg or detomidine 0.01 mg/kg. Heart rate and respiratory rate were recorded before sedation and at 1, 3, and 5 minutes after injection. Hourly measurements of rectal temperature were performed starting before sedation. RESULTS: All febrile horses experienced an episode of tachypnea and antipyresis after sedation. Rectal temperature in the febrile group was significantly lower at 1, 2, and 3 hours after sedation. In several measurements, the decrease was >1 degrees C. Respiratory rate in the febrile group was significantly increased after sedation. All febrile horses were breathing>40 breaths/min and 3 horses>100 breaths/min 5 minutes after sedation. No differences were noted between the 2 treatments. No significant changes in respiratory rate or temperature were noted in the reference group. CONCLUSIONS AND CLINICAL IMPORTANCE: Febrile horses can become tachypneic after sedation with detomidine or xylazine. The antipyretic properties of alpha2-agonists need consideration when evaluating patients that have been sedated several hours before examination.

Pharmacologic treatment of pediatric insomnia.

Pediatric insomnia is common in children and adolescents, particularly in children who have comorbid medical, psychiatric, and neurodevelopmental disorders, and may be associated with cognitive, emotional, and psychosocial impairments that often result in significant caregiver burden. Although several behavioral interventions for pediatric insomnia are effective, there is a relative paucity of empiric evidence supporting the use of pharmacologic treatment. Sedative/hypnotic drugs are frequently used in clinical practice to treat pediatric insomnia, and guidelines for the use of these medications in general as well as for specific medications have been developed. This review presents expert consensus guidelines for the use of these medications in clinical practice, with a focus on the different classes of pharmacologic agents that are most commonly prescribed.

STEMI in a 24-year-old man after use of a synephrine-containing dietary supplement: a case report and review of the literature.

Billions of dollars are spent annually in the United States in the largely unregulated market of dietary supplements. Many of these supplements are marketed as weight-loss and athletic-performance-enhancement products. The association of various ephedra-containing products with adverse cardiovascular events has led to a ban on the sale of these products by the U.S. Food and Drug Administration. The result has been the emergence of new formulations marketed for weight loss and athletic-performance enhancement that are "ephedra-free" but contain other sympathomimetic substances, the safety of which has not been established. We present the case of a previously healthy 24-year-old man who presented with an ST-segment-elevation myocardial infarction (STEMI) within hours of taking the ephedra-free product Nutrex Lipo-6x. Emergent coronary angiography revealed the presence of extensive, diffuse thrombus in the left anterior descending coronary artery. The patient had no risk factors for coronary artery disease or myocardial infarction; this includes the absence of a hypercoagulable state and the absence of a history of illicit drug use. This case of STEMI--associated as it is with the use of a synephrine-containing product by a person without risk factors for coronary artery disease--is to our knowledge the 1st reported in the literature. We discuss the patient's evaluation and clinical course, and we review the literature with respect to synephrine-containing dietary supplements. On the basis of synephrine's chemical composition and mechanism of action, we propose a direct association between this patient's use of Nutrex Lipo-6x and his STEMI.

Conscious sedation during ophthalmic surgery under local anesthesia.

Sedation during ophthalmic local anesthesia helps to ensure comfort and cooperation during eye surgery. Sedation requirements of ophthalmic patients have changed with the popularization of newer surgical and anesthetic techniques. Many sedative agents are available to anesthesiologists including benzodiazepines, intravenous anesthetic induction agents, narcotic analgesics and a-adrenoreceptor agonists. However, there is no single ideal sedative agent, regime or protocol that can completely cater to the wide spectrum of ophthalmic procedures performed in a heterogeneous patient population. Moreover, the clinical practice of sedation during ophthalmic surgery under local anesthesia is varied and not without risk of complications and adverse events. Hence, balanced sedative techniques should only be used after careful consideration of patient profile, the type of eye surgery, and patient and surgeon preferences. Good knowledge of the pharmacology of sedative agents is fundamental to their useful clinical application.

Dexmedetomidine sedation leading to refractory cardiogenic shock.

Dexmedetomidine is frequently used for deep sedation during electrophysiology procedures. We report a case where, presumably, the use of dexmedetomidine resulted in a patient's death. The patient developed unexplained and refractory cardiogenic shock and could not be resuscitated. Autopsy failed to demonstrate any abnormality or cause of death. We postulate that, in certain susceptible individuals, dexmedetomidine may lead to terminal complications. We therefore urge caution about using dexmedetomidine in the electrophysiology laboratory.

Tai-Kang-Ning, a Chinese herbal medicine formula, alleviates acute heroin withdrawal.

The efficacy and safety of Tai-Kang-Ning (TKN) capsule, a traditional Chinese medicine formula, for the treatment of acute heroin withdrawal syndrome were investigated by conducting a double-blind, double-dummy, positive-controlled, and randomized trial. Sixty-four patients with acute heroin withdrawal syndrome were recruited. These patients were treated with either TKN or lofexidine in a fixed schedule of doses for 10 days. The results indicate that both treatments significantly reduced withdrawal symptoms by day 3, but there was no significant difference overall between lofexidine and TKN in efficacy or safety. These results demonstrate that TKN is effective in the treatment of moderate-to-severe acute heroin withdrawal syndrome with mild adverse effects.

The effects of dexmedetomidine on cardiac electrophysiology in children.

BACKGROUND: Dexmedetomidine (DEX) is an alpha2-adrenergic agonist that is approved by the Food and Drug Administration for short-term (<24 h) sedation in adults. It is not approved for use in children. Nevertheless, the use of DEX for sedation and anesthesia in infants and children appears to be increasing. There are some concerns regarding the hemodynamic effects of the drug, including bradycardia, hypertension, and hypotension. No data regarding the effects of DEX on the cardiac conduction system are available. We therefore aimed to characterize the effects of DEX on cardiac conduction in pediatric patients. METHODS: Twelve children between the ages of 5 and 17 yr undergoing electrophysiology study and ablation of supraventricular accessory pathways had hemodynamic and cardiac electrophysiologic variables measured before and during administration of DEX (1 microg/kg IV over 10 min followed by a 10-min continuous infusion of 0.7 microg x kg(-1) x h(-1)). RESULTS: Heart rate decreased while arterial blood pressure increased significantly after DEX administration. Sinus node function was significantly affected, as evidenced by an increase in sinus cycle length and sinus node recovery time. Atrioventricular nodal function was also depressed, as evidenced by Wenckeback cycle length prolongation and prolongation of PR interval. CONCLUSION: DEX significantly depressed sinus and atrioventricular nodal function in pediatric patients. Heart rate decreased and arterial blood pressure increased during administration of DEX. The use of DEX may not be desirable during electrophysiology study and may be associated with adverse effects in patients at risk for bradycardia or atrioventricular nodal block.

Effects of THC and lofexidine in a human laboratory model of marijuana withdrawal and relapse.

INTRODUCTION: Individuals seeking treatment for their marijuana use rarely achieve sustained abstinence. OBJECTIVES: The objectives of the study are to determine if THC, a cannabinoid agonist, and lofexidine, an alpha(2)-adrenergic receptor agonist, given alone and in combination, decreased symptoms of marijuana withdrawal and relapse, defined as a return to marijuana use after a period of abstinence. MATERIALS AND METHODS: Nontreatment-seeking, male volunteers (n = 8), averaging 12 marijuana cigarettes/day, were maintained on each of four medication conditions for 7 days: placebo, tetrahydrocannabinol (THC) (60 mg/day), lofexidine (2.4 mg/day), and THC (60 mg/day) combined with lofexidine (2.4 mg/day); each inpatient phase was separated by an outpatient washout phase. During the first three inpatient days, placebo marijuana was available for self-administration (withdrawal). For the next 4 days, active marijuana was available for self-administration (relapse). Participants paid for self-administered marijuana using study earnings. Self-administration, mood, task performance, food intake, and sleep were measured. RESULTS: THC reversed the anorexia and weight loss associated with marijuana withdrawal, and decreased a subset of withdrawal symptoms, but increased sleep onset latency, and did not decrease marijuana relapse. Lofexidine was sedating, worsened abstinence-related anorexia, and did not robustly attenuate withdrawal, but improved sleep and decreased marijuana relapse. The combination of lofexidine and THC produced the most robust improvements in sleep and decreased marijuana withdrawal, craving, and relapse in daily marijuana smokers relative to either medication alone. CONCLUSIONS: These data suggest the combination of lofexidine and THC warrant further testing as a potential treatment for marijuana dependence.

Anti-emetic effect of oculo-acupuncture on dogs with xylazine induced vomiting.

The present study was conducted in order to clarify the anti-emetic effect of oculo-acupuncture (OA) on dogs with xylazine-induced vomiting, and also to compare the anti-emetic effect of OA and body acupuncture (AP). Twelve dogs induced to vomit by xylazine were selected from total 29 mongrel dogs in preliminary experiment and were used as subjects in this study. This study was comprised of two experiments. In experiment 1, the anti-emetic effects of OA on dogs were examined in the stomach/spleen region (experimental group I), the zhongjiao region (experimental group II), and the stomach/spleen region plus the zhongjiao region (experimental group III) using 12 dogs induced to vomit for one week interval repeatedly. On the other hand, needle acupuncture (AP) (BL20 + BL21, experimental group A) and OA (stomach/spleen and zhong jiao regions) combined with needle AP (BL20 + BL21) (experimental group B) were examined using 6 vomiting dogs, for one week interval repeatedly in experiment 2. As a result, the vomiting rates of experimental group I (50%, p < 0.05), experimental group II (58.3%) and experimental group III (41.6%, p < 0.01) were lower than that of control (100%), respectively in experiment 1. The vomiting rates of both experimental group A (50%, p < 0.05) and experimental group B (50%, p < 0.05) were lower than that of control (100%) in experiment 2. The starting vomiting time in experimental groups was similar to that of the control groups in experiment 1 and 2. This study demonstrated that OA had anti-emetic effects on dogs with xylazine-induced vomiting and OA in the stomach/spleen region plus the zhongjiao region was the most effective in anti-emesis among the experimental groups. In addition, body AP and OA combined with body AP had a similar anti-emetic effect on dogs with xylazine-induced vomiting.

Ligustilide reduces phenylephrine induced-aortic tension in vitro but has no effect on systolic pressure in spontaneously hypertensive rats.

Radix Angelica sinensis, known as Danggui in Chinese, has been used to treat cardiovascular diseases in traditional Chinese medicine for a long time. Experimental evidence showed that the essential oil of Danggui could reduce blood pressure in rabbits, cats or hypertensive dogs when given intravenously. In this study, we investigated the effects of Z-ligustilide, the main lipophilic component of the essential oil of Danggui on aortic tension induced by phenylephrine, an alpha-adrenergic agonist, in vitro and the systolic blood pressure in SHR rats. We demonstrated for the first time that ligustilide can significantly reduce the phenylephrine-induced aortic tension in vitro with IC(50) about 64 mug/ml, but has no in vivo effect on systolic blood pressure in SHR rats when administrated orally. The data on transport of ligustilide across Caco-2 monolayer suggested an efficient intestinal absorption of ligustilide in vivo, implying that the non-effectiveness of ligustilide in vivo is not due to the poor absorption in the gastrointestinal tract. Further studies on whether ligustilide is one of the main anti-hypertensive components of the essential oil are needed.

Characterization of spinal alpha-adrenergic modulation of nociceptive transmission and hyperalgesia throughout postnatal development in rats.

BACKGROUND AND PURPOSE: The selective alpha(2)-adrenergic agonist dexmedetomidine is used clinically for analgesia and sedation, but effects in early life are not well characterized. Investigation of age-related effects of dexmedetomidine is important for evaluating responses to exogenously administered analgesics and provides insight into postnatal function of noradrenergic pathways. EXPERIMENTAL APPROACH: We examined effects of epidural dexmedetomidine in anaesthetized rat pups (3, 10 and 21 postnatal days) using a quantitative model of nociception and C-fibre induced hyperalgesia. Electromyographic recordings of withdrawal responses to hindpaw mechanical stimuli measured effects of dexmedetomidine upon the baseline reflex and the response to mustard oil application on the hindpaw (primary hyperalgesia) or hindlimb (secondary hyperalgesia). In addition, we compared epidural with systemic administration, examined effects of spinal transection and evaluated heart rate changes following dexmedetomidine. KEY RESULTS: Epidural dexmedetomidine dose-dependently prevented mustard oil-induced hyperalgesia at all ages but dose requirements were lower in the youngest pups. Higher doses also suppressed the baseline nociceptive reflex when given epidurally, but had no effect when given systemically. Analgesic efficacy was the same for primary and secondary hyperalgesia, and was not diminished by spinal cord transection. CONCLUSIONS AND IMPLICATIONS: Our laboratory studies predict that spinally mediated alpha(2)-agonist analgesia would be effective throughout postnatal development, dose requirements would be lower in early life and selective anti-hyperalgesic effects could be achieved with epidural administration at doses lower than associated with antinociceptive or cardiovascular effects. Clinical trials of alpha(2) agonists in neonates and infants should consider developmentally regulated changes.

Radial artery angiographic string sign: clinical consequences and the role of pharmacologic therapy.

BACKGROUND: The radial artery is an increasingly important graft for coronary artery bypass surgery. Postoperative angiographic studies have shown that a proportion of radial grafts become diffusely narrowed but not occluded, or string signs. METHODS: Four hundred forty patients receiving a radial artery graft enrolled in a large clinical trial underwent postoperative angiography at 1 year. Angiograms were analyzed visually and quantitatively. A complete string sign was defined as diffuse narrowing along the full length of the graft, while a partial string sign was defined as segmental narrowing. Angiographic findings were correlated with medication compliance and clinical sequelae. RESULTS: Thirty-one patients (7.0 %) had radial artery graft string signs versus 4 patients (0.9%) with a saphenous vein graft string sign (p = 0.001). Complete string signs were present in 28 cases, and the mean diameter was 0.76 +/- 0.14 mm (mean +/- SD), whereas 3 cases had a partial string sign with a diameter of 0.89 +/- 0.14 mm. Fifteen radial arteries showed Thrombolysis in Myocardial Infarction Study (TIMI) 1 flow, 3 cases showed TIMI 2 flow, and 13 cases showed TIMI 3 flow. There was no difference in incidence of radial string sign between patients taking nifedipine versus diltiazem postoperatively. Multivariate analysis revealed the presence of radial artery string sign was closely related to the perioperative use of alpha-adrenergic agonists and target vessels stenosis less than 90%. Postoperative symptoms were associated with radial artery string signs with TIMI 1 flow (p = 0.0045). CONCLUSIONS: In the Radial Artery Patency Study, radial artery string sign was present in 7% of patients. Despite diffuse narrowing, 52% of grafts had TIMI 2 flow or better.

Reduction of adrenergic neurotransmission with clonidine aggravates spike-wave seizures and alters activity in the cortex and the thalamus in WAG/Rij rats.

The alpha-2 adrenoreceptor agonist clonidine in low dose inhibits the release of noradrenaline and aggravates absence seizures. The present study examines properties of two types of spike-wave discharges (SWD) in a genetic model of absence epilepsy, the WAG/Rij rats. After reduction of noradrenergic neurotransmission with clonidine (0.00625 mg/kg, i.p.), the electrical activity was recorded in the neocortex, the ventroposteromedial nucleus (VPM) and the reticular thalamic nucleus (RTN). Clonidine temporally reduced percentage of wakefulness but did not affect sleep. Clonidine decreased the spectral power of sleep EEG (mostly in the delta band), this effect was found in the cortex and in the VPM. Clonidine increased the incidence of SWD type I (generalized); the spectral power of SWD I was lower in the frontal cortex (mostly in 1-9 and 30-100 Hz) and in the VPM (1-5 Hz), but higher in the RTN (9-14 Hz). Local occipital SWD (type II) had a tendency to be less numerous after clonidine, they had a lower power in the 5-9 Hz band in the occipital cortex, in the VPM and in the RTN. It can be concluded that strengthening of 9-14 Hz activity in the RTN may underlie clonidine-induced aggravation of SWD I.