Bed Rest After Acute Myocardial Infarction: A Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Complete bed rest has been a component of the management of acute myocardial infarction, which was first diagnosed in the United States in 1912. The prescribed duration of bed rest has been progressively shortened in the past century. STUDY QUESTION: What are the milestones of the changes in the expert approach to the duration of bed rest for patients with acute myocardial infarction? STUDY DESIGN: To determine the changes in the experts' approach to the duration of bed rest after a diagnosis of acute myocardial infarction, as presented in a widely used textbook in the United States. DATA SOURCES: The chapters presenting the management of myocardial infarction in the 26 editions of Cecil Textbook of Medicine published from 1927 through 2020. RESULTS: Complete rest for 2-6 weeks was recommended by the Cecil's experts from 1927 through 1967. The practice was questioned since the early 1950s, but the recommended duration of bed rest was decreased to 3-4 days only in 1971, after most US hospitals opened coronary care units. The required time in bed was further decreased to 1 day in 1992 and to 12 hours in 2004. By 2007, the literature contained data from 15 trials with a total of 1471 patients kept in bed "longer" and 1487 patients who had been prescribed bed rest for "shorter" periods after an acute uncomplicate myocardial infarction and there was no difference between the groups regarding reinfarction, cardiac mortality, or all-cause mortality. CONCLUSIONS: The duration of bed rest after acute myocardial infarction recommended by experts in the United States has had a downward trend with an inflection point in the early 1970s. The change reflected experts' opinion, rather than evidence produced by randomized controlled trials.

Pharmacological Management of Cholera: A Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Cholera is a potentially lethal diarrheal disease produced by Vibrio cholerae serotypes O1 El Tor and O139. Known since antiquity, the condition causes epidemics in many areas, particularly in Asia, Africa, and South America. Left untreated, the mortality may reach 50%. The crucial therapeutic intervention is intravenous or oral rehydration and correction of acidosis, dyselectrolytemia, and renal impairment. Antibiotic use represents the main pharmacological intervention. STUDY QUESTION: What are the milestones of the antibiotics use recommended by experts for the pharmacological management of cholera in the past century? STUDY DESIGN: To determine the changes in the experts' approach to the management of cholera and particularly the use of antibiotics as presented in a widely used textbook in the United States. DATA SOURCES: The chapters describing the management of cholera in the 26 editions of Cecil Textbook of Medicine published from 1927 through 2020. RESULTS: Sulfonamides were recommended in 1947, followed by the introduction of tetracyclines, chloramphenicol, and furazolidone in 1955. The options were restricted in 2000 to doxycycline. In the past decade, patients infected with strains known to have a degree a resistance to tetracyclines were treated with azithromycin or ciprofloxacin. Antibiotic use decreases the volume of stool and the duration of diarrhea but has not been considered lifesaving. Drugs with antimotility, antiemetic, or antisecretory properties are not useful. CONCLUSIONS: The utility of antibiotic use in cholera has been endorsed by experts, but only as an adjunct to rapid and complete fluid and electrolyte replacement.

Pharmacological Management of Pulmonary Tuberculosis: A Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Advances in drug therapy for pulmonary tuberculosis have had an extraordinary impact on the incidence of tuberculosis in the United States in the past century, which has decreased from 113/100,000 persons in 1920 to 2.2/100,000 in 2020. Modern treatments have contributed to a remarkable decrease in hospitalizations and mortality and have had a significant impact on the duration and severity of illness, quality of life, and work potential of affected persons. STUDY QUESTION: What are the milestones of the changes in the expert approach to the pharmacological management of pulmonary tuberculosis in the past century? STUDY DESIGN: To determine the changes in the experts' approach to the management of pulmonary tuberculosis, as presented in a widely used textbook in the United States. DATA SOURCES: The chapters describing the management of pulmonary tuberculosis in the 26 editions of Cecil Textbook of Medicine published from 1927 through 2020. RESULTS: In the preantibiotic era (1927-1943), the Cecil authors emphasized rest, good food, and fresh air as the treatment pillars for pulmonary tuberculosis. The modern era (1947-1971) recorded the discovery of all the drugs that are still used for the initial treatment, in the following order: streptomycin, para-aminosalicylic acid, isoniazid, pyrazinamide, ethambutol, cycloserine, kanamycin, ethionamide, capreomycin, and rifampin. In the postmodern era (1975-2020), therapeutic advances continued with trials of many drug combinations aimed at ameliorating the duration of treatment, drug resistance adverse effects, and poor the recent addition of fluoroquinolones, bedaquiline, and clofazimine. CONCLUSIONS: The pharmacological management of tuberculosis has remained archaic until the middle of the 20th century. Fundamental progress occurred in a very short period (1947-1971) and was because of the recognition of the antituberculous effect of many antibiotics and chemotherapy agents. The challenges created by mycobacterial infections resistant to multiple drugs remain and have prompted the addition of new drugs in the past decade.

Pharmacological Management of Inflammatory Bowel Disease: a Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Advances in drug therapy for inflammatory bowel disease (IBD) [Crohn disease and ulcerative colitis (UC)] have contributed to a decrease in the severity of these chronic and disabling conditions. STUDY QUESTION: What are the milestones of the changes in the expert approach to the pharmacological management of IBD in the past century? STUDY DESIGN: To determine the changes in the experts' approach to the management of regional ileitis and UC, as presented in a widely used textbook in the United States. DATA SOURCES: The chapters presenting the management of IBD in the 26 editions of Cecil Textbook of Medicine published from 1927 through 2020. RESULTS: No specific interventions existed from 1927 through 1942. The pharmacological management of IBD has had 3 slightly overlapping eras starting in 1943. During the first period (1943-1951), the medical management relied on antibiotics, primarily sulfonamides and chloramphenicol. In the second (1955-75), experts recommended the use of adrenocorticotropic hormone or corticosteroids and 5-aminosalicylate. In the third era, which commenced in 1979 and is continuing to date, the pharmacological interventions have been expanded and refined to include 5 main drug classes, 5-aminosalicylates (sulfasalazine, mesalamine, and olsalazine), corticosteroids (prednisone and budesonide), immunomodulators (azathioprine, 6-mercaptopurine, cyclosporine, and tofacitinib), biologics (infliximab adalimumab certolizumab pegol, and natalizumab), and antibiotics (metronidazole and ciprofloxacin). A consensus exists that the monoclonal antibodies again tumor necrosis factor alpha are cost-effective for induction and maintenance of clinical remission in both UC (golimumab) and Crohn disease (certolizumab pegol). The newer agents ustekinumab (a monoclonal antibody to the interleukin p40 subunit) and vedolizumab (a monoclonal antibody to the homing receptor integrin complex) have also performed well. CONCLUSIONS: The pharmacological management of IBD has been the focus of intense research and development in the past 60 years. The pillars of drug treatment have been 5-aminosalicylates and corticosteroids. Recent pharmacological innovations (immunomodulators and biologicals) constitute an encouraging paradigm shift in the treatment of UC and Crohn disease.

Pharmacological Management of Heroin Withdrawal Syndrome: A Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Opioid use disorder continues to have a significant impact on public health morbidity and mortality throughout the United States and elsewhere. Managing opioid withdrawal is a critical treatment goal in individuals entering treatment with an active opioid use. STUDY QUESTION: What are the milestones of the changes in the expert approach to the pharmacological management of heroin withdrawal syndrome in the past century? STUDY DESIGN: To determine the changes in the expert approach to the management of heroin withdrawal syndrome, as presented in a widely used textbook in the United States. DATA SOURCES: The chapters on opioid dependence in the 26 editions of Cecil Textbook of Medicine published from 1927 through 2020. RESULTS: Opioid replacement taper with morphine (1927-1947), codeine (1931-1943), and methadone (1951-present) administered for 3-10 days has remained the main intervention. The anticholinergic drugs, scopolamine and atropine, were recommended from 1927 to 1943, but their use has never been backed by scientific evidence. Newer approaches relied on clonidine, an alpha-2 receptor agonist used since 1982, and buprenorphine, an opioid agonist/antagonist endorsed for the treatment of heroin withdrawal in 2000. CONCLUSIONS: The pharmacological management of heroin withdrawal syndrome in the past century has progressed from the introduction of methadone to the utilization of clonidine and buprenorphine. More recent advances in treating opioid use disorder have changed the goals of opioid withdrawal management to achievement of abstinence from all opioids to facilitation of long-term treatment with medications for opioid use disorder.

Pharmacological Management of Atrial Fibrillation: A Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Advances in drug therapy for atrial fibrillation (AF) have had a significant impact on the quality of life of a substantial majority of affected persons, which has contributed to a remarkable decrease in the frequency and severity of thromboembolic complications, hospitalizations, and mortality. STUDY QUESTION: What are the milestones of the changes in the expert approach to the pharmacological management of AF in the past century? STUDY DESIGN: To determine the changes in the experts' approach to the management of AF, as presented in a widely used textbook in the United States. DATA SOURCES: The chapters presenting the management of AF in the 26 editions of Cecil Textbook of Medicine published from 1927 through 2020. RESULTS: AF was consistently described in Cecil Textbook of Medicine as the most common sustained arrhythmia in adults. The authors emphasized its thromboembolic complications and potential for hemodynamic deterioration. Rate control with digitalis and rhythm control with quinidine were the standard in 1927. The pharmacological advances have focused on atrioventricular nodal blocking for rate control, conversion to and maintenance of sinus rhythm, and preventive anticoagulation. The first new class of drugs for rate control was beta-adrenergic receptor blockers, starting with propranolol which was introduced in 1979, followed by the calcium channel blocker verapamil in 1988. Rhythm control with amiodarone, a potassium channel blocker, has been recommended since 2004, and the sodium channel blockers propafenone and flecainide became part of standard therapy in 2008. Anticoagulation with warfarin was recommended starting in 2000, followed by the introduction of direct thrombin inhibitor in 2012 and factor Xa inhibitors in 2016. CONCLUSIONS: The pharmacological management of AF was unchanged for more than 50 years (1927-1979), a period during which the devastating effects of thromboembolic complications were not addressed. The major therapeutic advance is represented by preventive anticoagulation with the newer, safer, and more user-friendly direct thrombin and factor Xa inhibitors.

Pharmacological Management of Obesity: A Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Innovations in drug therapy for obesity have had a limited impact on the body mass index, prevalence of medical complications, quality of life, and work potential of a substantial majority of affected persons. STUDY QUESTION: What are the milestones of the changes in the expert approach to the pharmacological management of obesity in the past century? STUDY DESIGN: To determine the changes in the experts' approach to the management of obesity, as presented in a widely used textbook in the United States. DATA SOURCES: The primary sources were chapters describing the management of obesity in the 26 editions of Cecil Textbook of Medicine published from 1927 through 2020. Secondary sources were publications retrieved from Medline that clarified technical issues related to the development, regulatory approval, and use of the drugs mentioned in the Cecil Textbook of Medicine. RESULTS: Pharmacological interventions aimed at increasing caloric expenditures through thermogenesis were recommended from 1927 through 1943. Thyroid extracts were prescribed even in the absence of demonstrated hypothyroidism or decreased basal metabolic rate throughout this period. Dinitrophenol was mentioned in 1937, but was banned soon thereafter. Appetite suppression with amphetamine was considered useful from 1943 through 1988, after which the drug was replaced with other centrally acting molecules, such as fenfluramine in 1988, sibutramine in 2000, and rimonabant in 2008, which were in turn withdrawn because of major adverse effects. In the past decade, obesity has been treated with the appetite suppressants phentermine-topiramate, bupropion-naltrexone, lorcaserin, and liraglutide, and with orlistat, a drug promoting fat malabsorption. The change in weight produced by these drugs is generally modest and transient. CONCLUSIONS: The pharmacological management of obesity has remained frustratingly inefficient. The reasons for the relative lack of success may reside in the ever-growing access to dense, palatable, and relatively inexpensive food, coupled with the decrease in energy expenditure created by a sedentary lifestyle.

Pharmacological Management of Primary Arterial Hypertension: A Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Advances in drug therapy for primary (or essential) arterial hypertension have contributed to a significant decrease in the frequency and severity of strokes, coronary artery disease and heart failure, and chronic renal insufficiency. STUDY QUESTION: What are the milestones of the changes in the expert approach to the pharmacological management of arterial hypertension in the past century? STUDY DESIGN: To determine the changes in the experts' approach to the management of arterial hypertension, as presented in a widely used textbook in the United States. DATA SOURCES: The chapters presenting the management of arterial hypertension in the 26 editions of Cecil Textbook of Medicine published from 1927 through 2020. RESULTS: The pharmacological management of arterial hypertension has had 3 overlapping eras in the timeframe subject to our investigation. In the empiric era (1927-1947), experts were recommending nonspecific interventions for sedation. The premodern era (1955-1963) relied on ganglion blockers, sympathetic blockers, and direct vasodilators. The modern era (1967-2020), which includes drugs used in current clinical practice, saw the introduction of diuretics (1967), beta-blockers (1971), alpha-blockers (1982), calcium channel blockers (1985), angiotensin-converting enzyme inhibitors (1985), angiotensin receptor blockers (2000), and direct renin inhibitors (2008). CONCLUSIONS: The pharmacological management of arterial hypertension has been the focus of intense and successful research and development in the second half of the 20th century.

Prehospital Care of Coronary Artery Disease and Its Major Risk Factors in Geropsychiatric Inpatients.

BACKGROUND: Older adults with serious mental illness have a high prevalence of coronary artery disease and of its major risk factors, that is, arterial hypertension, dyslipidemia, and diabetes mellitus. The prevalence and clinical control of these conditions have not been compared in geropsychiatric inpatients with dementia versus those with mood or psychotic disorders. STUDY QUESTION: What is the prevalence and acuity of coronary artery disease, arterial hypertension, dyslipidemia, and diabetes mellitus among patients with dementia, mood, and psychotic disorders admitted for geropsychiatric care? STUDY DESIGN: Patients 65 years of age or older were identified in a cohort of 1000 patients consecutively admitted over a 3-year period to the geropsychiatric unit of a 200-bed mental health hospital in suburban New York. All patients had a structured clinical and laboratory evaluation within 72 hours of admission. DATA SOURCES: Primary psychiatric diagnoses, medical history, the frequency of poorly controlled cardiometabolic comorbidity requiring an immediate change in the management plan, and the Charlson Comorbidity Index (CCI). RESULTS: The 65 years and older patient sample (N = 689) had a mean age of 74.8 years, and 58.8% of the subjects were women. The 205 patients with dementia were older ( P < 0.001) than the 337 patients with mood disorders and the 147 patients with psychotic syndromes. The numbers of medical conditions and the CCI after exclusion of dementia were similar in patients with dementia versus patients without dementia. A substantial number of patients had poorly controlled arterial hypertension (51.2%), dyslipidemia (25.4%), diabetes (24.2%), and coronary artery disease (15.4%). Patients with dementia had a lower prevalence of poorly controlled dyslipidemia ( P = 0.0006), diabetes ( P = 0.0089), and coronary artery disease ( P = 0.045). CONCLUSIONS: Compared with mood or psychotic disorder, a diagnosis of dementia with behavioral disturbance seemed to be associated with better control of coronary artery disease, dyslipidemia, and diabetes mellitus in geropsychiatric inpatients.

Pharmacological Management of Myasthenia Gravis: A Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Advances in drug therapy for myasthenia gravis have had a significant impact on the quality of life and work potential of a substantial majority of affected persons and has contributed to a remarkable decrease in the frequency and severity of complications, hospitalizations, and mortality. STUDY QUESTION: What are the milestones of the changes in the expert approach to the pharmacological management of myasthenia in the past century? STUDY DESIGN: To determine the changes in the experts' approach to the management of myasthenia gravis, as presented in a widely used textbook in the United States. DATA SOURCES: The chapters presenting the management of myasthenia gravis in the 26 editions of Cecil Textbook of Medicine published from 1927 to 2020. RESULTS: Adequate feeding, absolute rest in bed, and "tonics" were the only interventions recommended for the care of patients with myasthenia gravis in 1927. Ephedrine and glycine were used in the early 1930s. Treatment with the anticholinesterases physostigmine and neostigmine was recommended in 1937, 3 years after Mary Walker discovered it in the United Kingdom. Immunosuppressant pharmacological interventions with prednisone and azathioprine have been considered the standard since 1975, and intravenous immune globulin was added to usual care in 1996. The newer immunosuppressant drugs mycophenolate, cyclosporine, and tacrolimus have expanded the arsenal since 2008, and the monoclonal antibodies rituximab and eculizumab have been mentioned in the textbooks published in 2012-2020. The first randomized clinical trial of drug therapy for myasthenia gravis was published in 1987. CONCLUSIONS: The pharmacological management of myasthenia gravis was revolutionized by the epiphany of an astute clinician in the 1930s. Immunosuppressant treatment was a logical step once the autoimmune nature of the condition was established. The major therapeutic advances highlight the values of empiricism and persistent attention to detail in treating relatively rare chronic disorders.

Pharmacological Management of Heart Failure: A Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Drug therapy for heart failure influences quality of life and work potential of affected persons and has contributed to decrease in hospitalizations and cardiovascular mortality. The current approach is the result of incremental progress in understanding the pathophysiology of the syndrome, introduction of new molecules, and repurposing existing drugs. STUDY QUESTION: What are the milestones of the changes in the expert clinicians' approach to the pharmacological management in the past century? STUDY DESIGN: To determine the changes in the experts' approach to the management of heart failure, as presented in a widely used textbook in the United States. DATA SOURCES: The chapters on the management of heart failure in the 26 editions of Cecil Textbook of Medicine published from 1927 through 2020. RESULTS: In 1927, heart failure was treated with powdered leaf or tincture of digitalis, mercury chloride, and theophylline. Patients with acute pulmonary edema received injections of atropine, adrenaline, and ouabain. The therapeutic milestones in heart failure were the introduction of loop diuretics and aldosterone antagonists (1971), vasodilator treatment with hydralazine and nitroglycerine (1979-1985), angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and selective beta-adrenergic blockers (1992-2000), and sacubitril-valsartan (2016). For acute pulmonary edema, the durable milestone was the treatment with morphine and furosemide (1971). CONCLUSIONS: The pharmacological management of heart failure in the past century has progressed in fits and starts, with latent periods between significant advances lasting 8-40 years. In chronological order, the major advances were efficient diuresis, afterload reduction, and blunting the neurohormonal response to hemodynamic stress and cardiac remodeling.

Pharmacological Management of Diabetes Mellitus: A Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Drug therapy for diabetes mellitus (DM) has had a significant impact on quality of life and work potential of affected persons and has contributed to a remarkable decrease in the frequency and severity of complications, hospitalizations, and mortality. The current approach is the result of incremental progress in using technological advances to increase the safety and effectiveness of insulin therapy and the introduction of new molecules as oral and injectable antidiabetic drugs. STUDY QUESTION: What are the milestones of the changes in the expert approach to the pharmacological management of DM in the past century? STUDY DESIGN: To determine the changes in the experts' approach to the management of DM, as presented in a widely used textbook in the United States. DATA SOURCES: The chapters on describing the management of DM in the 26 editions of Cecil Textbook of Medicine published from 1927 to 2020. RESULTS: In 1927, DM was treated with insulin extracted from the pancreas of large animals (cattle, hogs, and sheep) and purified with alcohol to prevent the tissues' proteolytic action on the hormone. The therapeutic milestones in DM marked 2 avenues for innovation. The first created advances in insulin therapy, starting with processes that led to the production of crystalline insulin and protamine zinc insulin (1937), synthetic human insulin (1996), and prandial (2000) and basal (2004) insulin analogues. The second was an effort to develop and introduce in clinical practice in the United States oral antidiabetic drugs, starting with tolbutamide, a sulfonylurea (1955), followed by metformin, a biguanide (1996), thiazolidinediones, alpha-glucosidase inhibitors, and benzoic acid derivatives (2000), dipeptidyl peptidase-4 inhibitors and glucagon-like peptide 1 receptor agonists (2008), and sodium glucose cotransporter 2 inhibitors (2020). A latent period of 40 years between significant advances was likely because of searches for new technologies (eg, recombinant DNA for the production of synthetic insulin and analogues) and, at least in part, to the impact of the controversial University Group Diabetes Project on the development and acceptance of oral antidiabetic drugs. CONCLUSIONS: The pharmacological management of DM has progressed unevenly, with a long latency period in the second half of the last century followed by highly encouraging advances in the first 2 decades of the 21st century. In chronological order, the major advances were synthetic insulins obtained through DNA recombinant technology, adoption of metformin as first line therapy, and introduction of antidiabetic medication classes that also promote weight reduction and cardiovascular health.

Pharmacological Management of Peptic Ulcer: A Century of Expert Opinions in Cecil Textbook of Medicine.

BACKGROUND: Advances in drug therapy for peptic ulcer have had a significant impact on quality of life and work potential of many millions of affected persons and have contributed to a remarkable decrease in the prevalence of the disease, frequency and severity of complications, hospitalizations, and mortality. STUDY QUESTION: What are the milestones of the changes in the expert approach to the pharmacological management of peptic ulcer in the past century? STUDY DESIGN: To determine the changes in the experts' approach to the management of peptic ulcer, as presented in a widely used textbook in the United States. DATA SOURCES: The chapters presenting the management of peptic ulcer in the 26 editions of Cecil Textbook of Medicine published from 1927 through 2020. RESULTS: Acid neutralization with alkalies was the only pharmacological intervention recommended in the textbooks published from 1927 to 1975. Atropine and other antimuscarinic agents were mainly used to relieve pain and acid secretion according to the paradigm "no acid no ulcer." The shift to the acid suppression paradigm started with the introduction of the histamine-2 receptor antagonist cimetidine in 1979, the proton-pump inhibitor omeprazole in 1988, and the prostaglandin agonist misoprostol in 1992. Finally, the eradication of Helicobacter pylori was codified in 1996. CONCLUSIONS: The pharmacological management of peptic ulcer has remained archaic well into the 20th century. Fundamental progress occurred in a very short period (1979-1996) and was due to paradigm shifts from acid neutralization to acid suppression and later the recognition of the role of H. pylori infection.

Hypoglycemia and Sudden Death During Treatment With Methadone for Opiate Detoxification.

CLINICAL FEATURES: We present a case of a middle-aged man admitted to an inpatient detoxification facility for withdrawal of intranasal heroin, alprazolam, and ethanol. The patient was placed on methadone and chlordiazepoxide tapers. Ondansetron and trazodone were prescribed as needed for symptom control. On the third hospital day, the patient was found unresponsive with blood glucose of 40 mg/dL. He had no history of glucose dysregulation. The patient was pronounced dead shortly thereafter. Methadone overdose was ruled the cause of death. THERAPEUTIC CHALLENGES: There have been studies linking methadone with glucose dysregulation. Hypoglycemia can induce changes in the electrical system in the heart, including lengthening QT interval, lengthening repolarization, and causing ST wave changes. In addition, there have been studies linking methadone treatment to QT interval prolongation and torsade de pointes. Ondansetron and trazodone have both been associated with cardiac conduction abnormalities. SOLUTION: We recommend initial blood glucose and cardiac monitoring in patients taking methadone 40 mg daily or higher.

Clozapine Rechallenge After Major Adverse Effects: Clinical Guidelines Based on 259 Cases.

BACKGROUND: Clozapine is widely prescribed for treatment-refractory schizophrenia, but its use is limited by many potentially life-threatening adverse effects. The risk of rechallenge after these complications has never been comprehensively assessed in controlled studies. Thus, clinical guidelines must rely on the published case reports. The number of such reports is likely to increase over time, and updated analyses of larger samples are needed, as they may lead to changes in clinical guidelines. STUDY QUESTIONS: How safe is the clozapine rechallenge after life-threatening adverse effects? STUDY DESIGN: The published case reports of clozapine rechallenge were identified in a MEDLINE search. We added 121 cases reported from 2012 through 2017 to the 138 cases reported from 1972 through 2011 analyzed by us in a previous publication. The 95% confidence intervals (CIs) of the successful rechallenge rate were calculated for each adverse effect with at least 5 published case reports. The rechallenge was considered a valid clinical option when the lower end of the CI range was at least 50%. RESULTS: A successful outcome was documented in 128/203 patients rechallenged after neutropenia (63.0%, CI, 56.0%-69.6%), 3/17 after agranulocytosis (17.7%, CI, 4.7%-44.2%), 11/17 after myocarditis (64.7%, CI, 38.6%-84.7%), and 7/7 after neuroleptic malignant syndrome (100%, CI, 56.1%-100%). Among the 15 patients with other clozapine-induced adverse effects, the rechallenge was successful in those with eosinophilia, cardiac complications other than myocarditis (QTc prolongation, pericarditis, cardiomyopathy, and atrial flutter), and gastrointestinal hypomotility. The rechallenge failed in patients who had developed pancreatitis or renal insufficiency. CONCLUSION: Clozapine rechallenge is a reasonable clinical option after return to baseline for patients who had developed neutropenia and neuroleptic malignant syndrome, but not after agranulocytosis or myocarditis. Data are insufficient to formulate rechallenge guidelines for any other clozapine-related adverse effects.