They are used by the oral route discount super p-force oral jelly express erectile dysfunction pills review, nasal insufflation (“snorting”) cheap 160 mg super p-force oral jelly with amex erectile dysfunction pump for sale, intramuscular or intravenous injection, and rectal insertion, with most ingestion occurring by nasal insufflation or oral ingestion (or both). Synthetic Cannabinoids These drugs consist of psychoactively inert dry plant material sprayed with synthetic cannabinoid receptor agonists. Ma Huang (Ephedra) The dietary supplement ephedra, also known as ma huang, contains ephedrine and its enantiomer pseudoephedrine. Ma huang increases catecholamines at synaptic areas in the brain and heart and directly stimulates alpha- and beta-adrenergic receptors. As a result, it typically induces an increase in heart rate, blood pressure, cardiac output, and peripheral resistance. Catecholamines and Beta-Adrenergic Receptor Agonists Catecholamines, administered exogenously or secreted by a neuroendocrine tumor (e. Similar abnormalities have been described with the excessive use of beta-adrenergic agonist inhalants and methylxanthines in patients with severe pulmonary disease. Several mechanisms may be responsible for the acute and chronic myocardial damage associated with catecholamines. They may exert a direct toxic effect on the myocardium through changes in autonomic tone, enhanced lipid mobility, calcium overload, free radical production, or increased sarcolemmal permeability. Alternatively, myocardial damage may be secondary to a sustained increase in myocardial oxygen demand and/or a decrease in myocardial oxygen supply (the latter caused by catecholamine-induced coronary arterial vasoconstriction or platelet aggregation). Energy Drinks Emergency department visits related to energy drinks have more than doubled to more than 20,000 visits annually. Cardiovascular complications reported after energy drink ingestion include arrhythmias (i. Adverse effects and toxicities associated with energy drinks have been attributed to (1) the high caffeine content and the fact that the drinks are often consumed in an excessive or rapid manner; (2) consumption by young individuals who may be caffeine naïve and prone to consume large quantities; (3) mixture with alcohol and other substances; and (4) other ingredients in the drinks that may increase the cardiovascular risks. Inhalants The inhalants may be classified as organic solvents, organic nitrites (such as amyl nitrite or amyl butyl), and nitrous oxide. Organic solvents include toluene (airplane glue, rubber cement, and paint thinner), Freon, kerosene, gasoline, carbon tetrachloride, acrylic paint sprays, shoe polish, degreasers (trichloroethylene), nail polish remover, typewriter correction fluid, adhesives, permanent markers, room fresheners, deodorants, dry-cleaning agents, and lighter fluid. These solvents are most often inhaled by children or young adolescents (so-called huffing, sniffing, or dusting). The inhalation of Freon, for example, can sensitize the myocardium to catecholamines; in such individuals, fatal arrhythmias have been reported to occur when the user is startled during inhalation. Not surprisingly, therefore, patients treated with these agents have an increased risk for atherosclerosis (see also Chapter 82). Epidemiologic studies have linked certain antiretroviral medications (some nucleoside reverse transcriptase inhibitors [i. Conversely, nonnucleoside reverse transcriptase inhibitors, entry inhibitors, and integrase inhibitors do not appear to 40 increase the risk for coronary heart disease. Serotonin Agonists The medicinal use of serotonin agonists, such as ergotamine and methysergide (migraine therapy), bromocriptine, cabergoline, and pergolide (Parkinson disease therapy), and fenfluramine and dexfenfluramine (appetite suppressants) has been associated with left- and right-sided valvular disease (Table 80. The echocardiographic and histopathologic findings resemble those described in patients with carcinoid syndrome. Grossly, the valve leaflets and chordae tendineae are thickened and have a glistening white appearance. Histologically, the leaflet architecture is intact, but a plaquelike encasement of the leaflets and chordal structures occurs, and proliferative myofibroblasts surrounding an abundant extracellular matrix are observed. Its vasoconstrictor effects are exaggerated by concomitant caffeine ingestion or use of beta-adrenergic blockers. Triptans, selective 5-hydroxytryptamine agonists, also exert their therapeutic effects by inducing cerebral arterial vasoconstriction. Environmental Exposures Exposure to environmental pollutants and/or toxins can occur by three different routes: inhalation, ingestion, or dermal absorption. The physiologic response to a given exposure to an environmental pollutant may vary between individuals because of differences in their underlying health status or polymorphisms in the genes encoding detoxifying enzymes, as well as other factors. In the section that follows we will review the cardiovascular effects of metal pollutants and other environmental toxins. The effects of air pollution on cardiovascular disease are discussed in Chapter 52. Metal Pollutants Epidemiologic and experimental studies both suggest that metals (e. Cobalt In the mid-1960s, an acute and fulminant form of dilated cardiomyopathy was described in heavy beer drinkers. It was suggested that the cobalt chloride that was added to beer as a foam stabilizer was the causative agent; therefore, its addition was discontinued. More recently, several reports of dilated cardiomyopathy after occupational exposure to cobalt have appeared; in these individuals, high concentrations of cobalt were demonstrated in endomyocardial biopsy specimens. Lead Environmental exposure to lead can occur from air and dust, and sometimes from drinking water and food. Although public health interventions that banned the use of lead in gasoline, paint, and solder have reduced the overall lead exposure, both children and adults have continued lead exposure because of its use in batteries and toys and its release through industrial sources, as well as the persistence of lead in house paint, plumbing fixtures, and soil. Prospective and cross-sectional studies have demonstrated an association between the current levels of lead exposure and the risk of adverse cardiovascular outcomes. Moreover, in cross-sectional studies, blood lead levels were associated with peripheral arterial disease. Moderate to high levels of lead exposure are nephrotoxic, whereas low levels of lead exposure can lead to the development and progression of chronic kidney disease. Patients with lead poisoning typically have complaints that are referable to the gastrointestinal and central nervous systems. On occasion, subjects with lead poisoning have electrocardiographic abnormalities, atrioventricular conduction defects, and overt congestive heart failure; rarely, myocardial involvement may contribute to 43 or be the principal cause of death. Cadmium Cadmium is a by-product of the mining and refining of zinc, lead, and copper ores. The use of cadmium has increased dramatically through applications such as nickel-cadmium batteries and metal coatings. Cadmium from industrial sources and phosphate fertilizers containing cadmium fertilizers contaminate the soil. Leafy green and root vegetables concentrate cadmium bound to organic matter in soil, leading to a major cadmium exposure pathway through diet and tobacco smoking. Epidemiologic studies suggest there is an association between exposure to cadmium and cardiovascular and kidney disease. Increased levels of cadmium in blood or urine are associated with a higher incidence of death from coronary heart disease, heart failure, and stroke. Mercury Occupational exposure to metallic mercuric vapor may cause systemic arterial hypertension and myocardial failure. Although some studies have suggested that high mercury content in fish may counteract the beneficial effects of its omega-3 fatty acids, thereby increasing the risk for atherosclerotic cardiovascular disease, more recent assessments have not supported an association between total mercury exposure and the risk for coronary artery disease. Antimony Various antimony compounds have previously been used for the treatment of patients with schistosomiasis. Rarely, chest pain, bradycardia, hypotension, ventricular arrhythmias, and sudden death have been reported.
Piraccini E super p-force oral jelly 160mg without a prescription erectile dysfunction drugs that cause, Albarello R order 160 mg super p-force oral jelly visa erectile dysfunction treatment fruits, Biagini C, et al: Spinal anesthesia plus ketamine- medazolam sedation for pediatric orthopedic surgery in a developing country. Racca F, Mongini T, Wolfler A et al: Recommendations for anesthesia and perioperative management of patients with neuromuscular disorders. Children develop lesions associated with minimal trauma, which most commonly result in contractures of the hands and feet, mouth, and esophagus. Hand surgery typically involves opening up the contracted fingers by removing the cocoon of epidermis. The defects are grafted with full-thickness skin grafts, typically taken from the abdomen. Following sedation or anesthesia, the affected extremity is gently sponged with dilute chlorhexidine solution. The cocoon of scar tissue is removed, the fingers manipulated to expose the defects, and a full-thickness skin graft harvested. Generous Bactroban ointment and nonadhesive dressings are placed on the hand, and a well-padded cast is applied at the end of the procedure. The junctional form often is diagnosed at birth, with blisters caused by the physical trauma of delivery. Patients with the recessive dystrophic form may have strictures of the oropharynx, larynx, and esophagus. Periop hydrocortisone treatment may be required to compensate for adrenal suppression. The following should be available: Albolene liquefying cleanser, Surg-O-Flex (flexible tubular bandage), Vaseline gauze, Zeroform, Kerlix, Webril, cotton umbilical tape, Mepitel dressing, and Coban wrap. Carefully trim the adhesive off the pulse oximetry probe, wrap around the palm or finger, and wrap Coban around the probe. Venipuncture can be difficult, and the iv lines are secured with Vaseline gauze and Coban. Succinylcholine + should be used with caution due to potential K 2° muscle atrophy, although it has been used safely in many instances. Titrate both medications according to patient’s response to the surgical stimulation. Inhalation anesthesia: Inhalation anesthesia may also be performed in cases of difficult iv access and low risk of aspiration. Local anesthesia: At our institution, deep local anesthetic infiltration may be used. Allegaert K, Naulaers G: Gabapentin as part of multimodel analgesia in a newborn with epidermolysis bullosa. Borgeat A, Blumenthal S: Postoperative pain management following scoliosis surgery. Boschin M, Ellger B, Van Den Heuvel I, et al: Bilateral ultrasound-guided axillary plexus anesthesia in a child with dystrophic epidermolysis bullosa. Herod J, Denyer J, Goldman A, et al: Epidermolysis bullosa in children: pathophysiology, anaesthesia and pain management. Iohom G, Lyons B: Anaesthesia for children with epidermolysis bullosa: a review of 20 years’ experience. Rarely, these are related to conditions such as Crouzon, Apert, Saethre-Chotzen, and Pfeiffer syndromes. Single or multiple sutures can be involved, the most common being the sagittal suture. Anterior or posterior plagiocephaly involves a single coronal suture or lambdoid suture and is characterized by flattening of the forehead on the affected side. Oxycephaly (“tower-head deformity”) involves bilateral coronal sutures, with a flat, high forehead, whereas brachycephaly also involves the cranial base sutures and results in bitemporal bulging, midfacial hypoplasia, an anterior open bite, and hypertelorism. These patients may have severe sleep apnea and can pose a challenge for airway management. Skull shape abnormalities in metopic synostosis: Regions of reduced bone deposition (‒‒‒). Frontal/orbital abnormalities are addressed with bifrontal craniotomy and forehead advancement, along with advancement of the supraorbital bar (fronto-orbital advancement; Fig. For example, in plagiocephaly, because of the unilateral coronal synostosis, the frontal bone is retruded and the superior orbital rim is elevated and retruded on this side. Craniectomy is performed, the forehead is removed, the involved coronal suture is resected, and the supraorbital bar is cut above the orbit and down to the lateral orbital wall across the midline. Additional bone strips are taken from the posterior cranium and split for use as graft material; the other bone pieces are replaced and fixed with wires, suture, or restorable plates, which is the most common method now. B: Fronto-orbital advancement in a tongue-in-groove manner and fixation with wires. Resection of the involved suture and barrel staving of the cranium, with grafting for reshaping, works well. Brain mass doubles in size the first 6 mo and triples by 3 yr of age, when ~80% of the brain growth is completed (the driving force for cranial vault growth). In anticipation of major blood loss, transfusion should be started with the first incision. Severe life-threatening blood loss can occur if the sagittal sinus is breached, and neurosurgical repair must be accomplished quickly. Elevation of the bone flaps usually causes diffuse bleeding, which is stopped easily with irrigated bipolar cautery and thrombin- soaked sponges. It is useful to have the patient in the reverse Trendelenburg position from the start. Diffuse bleeding at the cut bone edges and over the bone surfaces can be further controlled with bone wax. Focal bleeding from around the orbit and in the temporal fossa region subperiosteally also can be controlled with bone wax. A LeFort/monobloc component to the surgery increases blood loss, especially during the initial mobilization of the facial segment. Local anesthetic with epinephrine injected, and/or on sponge packs for pressure, will control the diffuse mucosal bleeding. Variant procedure or approaches: In older children (> 2 yr), split cranial bone grafts may be required to correct defects caused by bone-flap advancement. Surgery is often performed between 3 and 6 mo of age, preferably when the infant weighs > 5 kg. Chiaretti A, Pietrini B: Safety & efficacy of remifentanil infusion in craniosynostosis repair in infants. Farbod F, Kanaan H, Farbod J: Infective endocarditis and antibiotic prophylaxis prior to dental/oral procedures: latest revision to the guidelines by the American Heart Association published April 2007. Schindler E, Martini M, Messing-Junger M: Anesthesia for plastic and craniofacial surgery.
Fibula direct blunt force trauma purchase super p-force oral jelly 160mg with amex erectile dysfunction generic drugs, ofen directed to the lateral aspect of the lower leg cheap super p-force oral jelly 160mg on-line erectile dysfunction caused by lipitor. Fractures of the fbula are fre- Anatomy quently associated with injuries to the ankle or knee. Less commonly, rotational forces centered on the ankle joint can lead to Etiology indirect torsion forces to the fbula with a subsequent ἀ e presence of the tough interosseous membrane spiral fracture. Isolated fractures of the fbula may be seen with ticularly common in older females. Maisonneuve described a fracture of the proximal more dispersed application of the force to the body of fbula with an associated rupture of the syndesmotic lig- the trauma victim, and sports utility vehicles are usu- ament and an injury to the medial ankle . Unless the depressed ruption of the syndesmosis and fnally a fracture of the area of bone was quite sizeable, it is unlikely to be identi- proximal fbula. Interestingly in a laboratory study of isolated tibia specimens impacted with a 1 cm steel loading stamp causing a fracture, no localized depressed fractures were seen . Forensic Issues in Fractures ἀ e direction of the application of blunt force in a to the Lower Leg motor vehicle to pedestrian incident has traditionally been deduced following the recognition of the wedge- Pedestrians shaped Messerer fracture . Depending upon the dynamics of the incident, a the application of force and whether a motor vehicle was trauma victim may not be struck on the presenting braking at the time of the incident. It would appear intuitive were in the context of the classical passenger sedan that a perpendicular force applied to a long bone, which with a projecting bumper bar. In a laboratory experi- been a marked increase in the number of sports utility ment using an isolated human tibial specimen, this was vehicles on the roads. More molded bumpers leads to a shown to occur in the isolated tibia with force applied to K13836. If the measurement of the fracture tion of fractured bones within the tissues adequately length is less than the bumper height it is then inferred refects the action of the severe forces applied to the bone. One cannot be sure of what of the boot in a case report of two pedestrians, an injury other forces were applied to the right thigh and lef lower that is analogous to boot top fractures in skiers . Other concerns such as the primary contact point to Fractures Involving the Foot the deceased’s body may well be an issue. Excluding simple fractures involving the toes, foot frac- tures are not particularly common traumatic injuries. Anatomy ἀ e most commonly injured group is adult men ἀ e talus is a resilient bone comprising a head, neck, and who have sufered signifcant axial loading to the foot. A body, with approximately two-thirds covered by carti- fracture of the calcaneus is associated with high velocity lage. Mechanism Epidemiology Calcaneal fractures have distinctive features depend- Fractures of the talus are not common. Up to three-quarters of the fractures are second most frequently fractured tarsal bone. Axial loading produces shear and com- spective analysis of 388 patients who underwent mul- pression forces within the calcaneus. The fracture is often recognized when actively sought in the typical circumstances, such as falls from a height or certain motor vehicle incidents. Mechanism ἀ e ensuing injury is cuboid dislocation in a plantar- Falls from a height and motor vehicle incidents are the medial direction as the bone is pushed up by the heads classical causes of a fracture to the talus. Axial compression forces can produce fractures of abduction of the midfoot or forefoot, usually in combi- the neck of the talus (Figure 10. Plantar dislocation may also rarely occur from sec- Cuboid ondary rotation of the cuboid on the navicular secondary Anatomy to severe twisting upon the weight-bearing foot . Anatomy Epidemiology ἀ e navicular is a medial midfoot tarsal bone which Fractures of the cuboid are uncommon injuries. Forced eversion of the cuboid on the hind foot is Fractures of the body of the navicular are uncommon. Forced plantar fexion–inversion leads to navicular is crucial for maintaining medial longitudinal compression of the cuboid. Nutcracker injuries Cuboid dislocation may occur with a fall from a sig- indicate the application of severe forces to the foot as nifcant height onto an everted forefoot. A case report of a cuboi- most commonly results in transverse or comminuted dal fracture that occurred in a motor vehicle collision fractures. Indirect trauma occurs when the body is described a mechanism involving forced plantar fexion twisted upon the fxed foot. Epidemiology Falls from a height onto the plantar fexed foot or Fractures of the cuneiform bones are uncommon “bracing” of the foot at the time of impact in a motor injuries. Although isolated fractures of the cunei- vehicle collision are typical mechanisms involved in forms have been reported in the literature, usually fractures involving the tarsometatarsal complex. In the absence of this dissec- incidents, which comprise about 40% of the injuries. Forced hyperextension may tear the ante- rior cruciate ligament, whereas a fall to the fexed knee may rupture the posterior cruciate ligament. Joint Injury to the Lower Leg ἀ e medial collateral ligament is more prone to rup- ture than the lateral collateral ligament and the anterior Knee cruciate ligament is ruptured more ofen than the poste- Anatomy rior cruciate ligament in a ratio of approximately 10:1. Following autopsy examination of the sub- Knee injuries are seen as a consequence of direct contact articular tibial and femoral epiphyses for bone contu- as well as noncontact insults to the joint. An injury to a knee ligament can be predicted from the Rather than being an efect of direct blunt force mechanism of injury. An injury that results in forced trauma the epiphyses showed contusions secondary to K13836. Femoral epiphyseal fractures are classifed accord- • Sagittal and coronal reconstructions are used to ing to the Salter and Harris system . Anatomy Fractures of the tibial tubercle involve avulsion of ἀ e ankle joint is a hinge joint allowing fexion and the tubercle and may have associated extension of the extension with a small degree of rotation and transla- fracture to the tibial articular surface. Etiology Ankle fractures that involve the talus usually occur Ankle fractures are common injuries. Injuries to the talar situation, an ankle fracture is the most common frac- neck are most frequently the result of forced dorsifex- ture to be managed by orthopedic surgeons . Ankle ion, whereas fractures of the talar dome are usually the fractures are usually defned as an injury involving the result of inversion of the ankle. Femur fractures in through the middle of the lateral malleolus and a verti- relatively low speed frontal crashes: ἀ e possible role of cal fracture through the medial malleolus. Subtrochanteric fractures of the Multidetector computed tomography in acute joint frac- femur. Anatomy puted tomography with two- and three-dimensional of the Lisfranc joint complex. Masses of maggots also guided by classic forensic factors, such as the circum- tend to be in regions that are shielded from direct light. A care- ἀ e presence of maggots in a body region away from a ful external examination of the remains by a forensic normal orifce suggests the presence of preexisting ante- pathologist is crucial to resolve the majority of cases. Burning can cause marked brittleness of the neighboring residual bone and ἀ e markedly burnt remains of a middle-aged woman lead to considerable artifacts. Following dissection of fuid cools it can have the appearance of blood around the heat-afected skeletal muscles and inspection of the K13836.
The use of increasing doses of vasodilators buy generic super p-force oral jelly 160 mg on line crestor causes erectile dysfunction, with or without a marked decline in intravascular volume as a result of concomitant diuretic therapy buy 160mg super p-force oral jelly with mastercard erectile dysfunction remedies natural, may lower renal perfusion pressure below that necessary to maintain normal autoregulation and glomerular filtration in patients with renal artery stenosis from atherosclerotic disease. Therefore, a reduction in renal blood flow may occur despite an increase in cardiac output, thereby leading to a decrease in diuretic effectiveness. In outpatients, a common and useful method for treating the diuretic-resistant patient is to administer two classes of diuretic concurrently. Adding a proximal tubule diuretic or a distal collecting tubule diuretic to a regimen of loop diuretics is often dramatically effective. As a general rule, when adding a second class of diuretic, the dose of loop diuretic should not be altered because the shape of the dose-response curve for loop diuretics is not affected by the addition of other diuretics, and the loop diuretic must be given at an effective dose for it to be effective. The combination of loop and distal collecting tubule diuretics has been shown to be effective 25 through several mechanisms. One is that distal collecting tubule diuretics have longer half-lives than loop diuretics and may thus prevent or attenuate postdiuretic NaCl retention. A second mechanism by + which distal collecting tubule diuretics potentiate the effects of loop diuretics is by inhibiting Na transport along the proximal tubule, since most thiazide diuretics also inhibit carbonic anhydrase, as well as by inhibiting NaCl transport along the distal renal tubule, which may counteract the increased solute resorptive effects of the hypertrophied and hyperplastic distal epithelial cells. The selection of distal collecting tubule diuretic to use as second diuretic is a matter of choice. Distal collecting tubule diuretics may be added in full doses (50 to 100 mg/day hydrochlorothiazide or 2. However, such an approach is likely to lead to excessive fluid and electrolyte depletion if patients are not followed extremely closely. One reasonable approach to combination therapy is to achieve control of fluid overload by initially adding full doses of distal collecting tubule diuretic on a daily basis and then decreasing the dose of the distal collecting tubule diuretic to three times weekly to avoid excessive diuresis. This approach requires the use of a constant-infusion pump but permits more precise control of the natriuretic effect achieved over time, particularly in carefully monitored patients. This impairment in renal function often is dismissed as “pre-renal”; however, when measured carefully, neither cardiac output nor renal perfusion pressure have been shown to be reduced in diuretic-treated patients who develop the cardiorenal syndrome. Importantly, worsening indices of renal function contribute to longer 28 hospital stays and predict higher rates of early rehospitalization and death (see Fig. The mechanisms for and treatment of the cardiorenal syndrome remain poorly understood. Device-Based Therapies Mechanical methods of fluid removal may be needed to achieve adequate control of fluid retention, particularly in patients who become resistant and/or refractory to diuretic therapy(see Chapter 24). Alternative extracorporeal methods include continuous hemofiltration, hemodialysis, or hemodiafiltration. The primary endpoint was total weight loss during the first 48 hours of randomization and the change in dyspnea score during the first 48 hours of randomization. In addition to extracorporeal methods for relieving volume overload, peritoneal dialysis can be used as a viable alternative therapy for the short-term management of refractory congestive symptoms for patients in whom vascular access cannot be obtained, or for whom appropriate extracorporeal therapies are not available. Participants treated with enalapril had significantly lower mortality than those treated with the vasodilatory combination of hydralazine plus isosorbide dinitrate (which does not directly inhibit neurohormonal systems). Nonetheless, it should be emphasized that patients with a low blood pressure (<90 mm Hg systolic), or impaired renal function (serum creatinine >2. Thus the efficacy of these agents for this latter patient population is less well established. Potassium retention may also become problematic if the patient is receiving potassium supplements or a potassium-sparing diuretic. The combination of hydralazine and an oral nitrate should be considered for these latter patients (see Table 25. Therefore the problems of symptomatic hypotension, azotemia, and hyperkalemia will be similar for both these agents. However, compliance with this combination has generally been poor because of the large number of tablets required and the high incidence of adverse reactions. A, Death from cardiovascular causes or hospitalization for heart failure (the primary endpoint). There are additional concerns about effects of sacubitril/valsartan on the degradation of beta- amyloid peptide in the brain, which could theoretically accelerate amyloid deposition. Beta blockers interfere with the harmful effects of sustained activation of the central nervous system by competitively antagonizing one or more alpha- and beta-adrenergic receptors (α , β ,1 1 and β ). Although there are a number of potential benefits to blocking all three receptors, most of the2 deleterious effects of sympathetic activation are mediated by the β -adrenergic receptor. The dose of beta blocker should be increased until the doses used are similar to those reported to be effective in clinical trials (see Table 25. Therefore, it is important to optimize the dose of diuretic before starting therapy with beta blockers. The increased fluid retention can usually be managed by increasing the diuretic dose. Nonetheless, a subset of patients (10% to 15%) remain intolerant to beta blockers because of worsening fluid retention or symptomatic hypotension. Metoprolol tartrate at an average dose of 108 mg/day reduced the prevalence of the primary endpoint of death or need for cardiac transplantation by 34%, which did not quite reach statistical significance (P = 0. The benefit resulted entirely from a reduction by metoprolol in the morbidity component of the primary endpoint, with no favorable trends in the mortality component. Lancet 1999;353:2001-7; and Packer M et al, for The Carvedilol Prospective Randomized Cumulative Survival Study Group. The two strategies were compared in a blinded manner with regard to the combined primary endpoint of all-cause mortality or hospitalization, as well as with regard to each of the components of the primary endpoint individually. Trials Program, composed of four individual trials managed by single Steering and Data and Safety Monitoring Committee, was stopped prematurely because of a highly significant (P < 0. Rates of hospitalization were also significantly lower for patients treated with carvedilol (48%) compared to placebo (58%). Carvedilol was associated with a significant 33% reduction in all-cause mortality compared with metoprolol tartrate 8,12 (33. Not all studies with beta blockers have been universally successful, suggesting that their effects should not necessarily be viewed broadly as a class effect. Indeed, early studies with the first-generation of nonspecific β and β receptors without ancillary vasodilating properties (e. The differential response of bucindolol in white patients has been suggested to be secondary to a polymorphism (Arginine 389) in the β -adrenergic receptor that is more prevalent in white patients (see online supplement,1 Pharmacogenomics in Heart Failure). Side Effects of Beta Blockers The adverse effects of beta blockers are generally related to the predictable complications that arise from interfering with the adrenergic nervous system. These reactions generally occur within several days of initiating therapy and are generally responsive to adjusting concomitant medications, as previously described. Treatment with a beta blocker can be accompanied by feelings of general fatigue or weakness. In most patients, the increased fatigue spontaneously resolves within several weeks or months; in some, however, it may be severe enough to limit the dose of beta blocker or require the withdrawal or reduction of treatment.