Current trends in the pharmacotherapy for peptic ulcer disease.

A variety of options are available for the medical treatment of peptic ulcer disease, including antacids, histamine2 receptor antagonists, omeprazole, prostaglandin analogues, and sucralfate and bismuth formulations. Seventy percent to 90% of peptic duodenal and gastric ulcers will heal after 4 to 8 weeks of therapy. Combination regimens using these agents have not been demonstrated to be superior to single-agent therapy. Aggressive acid suppression with "high-dose" histamine2 receptor antagonists or omeprazole accelerates healing of ordinary ulcers and promotes healing of previously refractory ulcers. Although ulcer recurrence is diminished by continuous "maintenance" therapy with the aforementioned agents, recurrence seems to be dramatically suppressed after eradication of Helicobacter pylori from the gastroduodenal mucosa.     

What is the optimal medical therapy for Barrett's esophagus?

The development of Barrett's esophagus (BE) in patients with gastroesophageal reflux disease (GERD) is troubling because of its known association with esophageal cancer. When evaluated clinically, patients with BE have the severest form of GERD and require aggressive therapy to control esophageal acid exposure. Both hypotension of the lower esophageal sphincter and the extent of esophageal acid exposure are major contributors to severe GERD and its complications. It is hypothesized that better control of acid will improve outcomes for BE patients. While it is clear that therapy (medical or surgical) for reflux rarely if ever results in total regression of BE, there are some limited data to support improvement in BE with control of reflux. Current medical choices include prokinetic agents, histamine type-2 receptor antagonists, and proton pump inhibitors. In the future, genetic markers may be used in identifying BE patients at the greatest risk for histologic progression, and chemoprevention with cyclooxygenase-2 inhibitors may be a therapeutic option. This paper will review the rationale for and results of medical antireflux therapy in patients with BE.     

New pharmacological agents for the treatment of gastroesophageal reflux disease

Proton pump inhibitors (PPIs) are currently the most effective and most widely used agents for gastroesophageal reflux disease (GERD). Despite the efficacy of these agents in healing and symptom relief, a substantial proportion of patients require twice-daily therapy with PPIs, and break-through symptoms cause others to use over-the-counter antacids and histamine 2-receptor antagonists to supplement their PPI therapy. Major strategies that are being pursued include the development of agents that have a faster onset of action for on-demand therapy; have better control of acid secretion, resulting in improved healing in advanced grades of esophagitis and better symptom control; and agents that decrease transient lower esophageal sphincter relaxations (TLESRs), thereby reducing distal acid exposure and weakly acidic refluxate. A number of new pharmaceutical agents are currently undergoing clinical evaluation for the treatment of GERD. These include agents that reduce TLESRs, serotonergic agents/ prokinetics, long-acting PPIs, mucosal protectants, and antigastrin agents. One or more of these agents may be the future of GERD therapy.     

Omeprazole in H2 receptor antagonist-resistant reflux esophagitis

We conducted a retrospective review of 25 patients with severe reflux esophagitis treated with omeprazole because of failure of H2 receptor antagonists to heal their esophagitis. Prior to beginning omeprazole (40 mg/day), all patients were on H2 antagonists for at least 9 months and still had endoscopic evidence of longitudinal (grade II) or circumferential (grade III) distal esophageal ulceration. Omeprazole therapy brought about complete endoscopic healing in 24 of 25 patients (96%). Twenty-three of 24 healed patients were then restarted on H2 antagonists as maintenance therapy. Repeat endoscopy was performed if symptoms recurred. Fourteen of 24 patients (58%) had recurrence of endoscopic esophagitis documented between 26 and 300 days from the time of starting maintenance therapy. Two of these 14 patients opted for antireflux surgery, whereas the remaining 12 were once again given omeprazole, which again resulted in symptom resolution in all patients. These data suggest that most patients with H2 receptor antagonist-resistant ulcerative esophagitis cannot be successfully maintained on H2 antagonists even after the ulcers have been healed with omeprazole. Further studies are required to determine the role of omeprazole compared to other treatments in the long-term maintenance therapy of these patients.     

Canadian Consensus Conference on the management of gastroesophageal reflux disease in adults - update 2004.

BACKGROUND: Gastroesophageal reflux disease (GERD) is the most prevalent acid-related disorder in Canada and is associated with significant impairment of health-related quality of life. Since the last Canadian Consensus Conference in 1996, GERD management has evolved substantially. OBJECTIVE: To develop up-to-date evidence-based recommendations relevant to the needs of Canadian health care providers for the management of the esophageal manifestations of GERD. CONSENSUS PROCESS: A multidisciplinary group of 23 voting participants developed recommendation statements using a Delphi approach; after presentation of relevant data at the meeting, the quality of the evidence, strength of recommendation and level of consensus were graded by participants according to accepted principles. OUTCOMES: GERD applies to individuals who reflux gastric contents into the esophagus causing symptoms sufficient to reduce quality of life, injury or both; endoscopy-negative reflux disease applies to individuals who have GERD and a normal endoscopy. Uninvestigated heartburn-dominant dyspepsia - characterised by heartburn or acid regurgitation - includes erosive esophagitis or endoscopy-negative reflux disease, and may be treated empirically as GERD without further investigation provided there are no alarm features. Lifestyle modifications are ineffective for frequent or severe GERD symptoms; over-the-counter antacids or histamine H2-receptor antagonists are effective for some patients with mild or infrequent GERD symptoms. Proton pump inhibitors are more effective for healing and symptom relief than histamine H2-receptor antagonists; their efficacy is proportional to their ability to reduce intragastric acidity. Response to initial therapy - a once-daily proton pump inhibitor unless symptoms are mild and infrequent (fewer than three times per week) - should be assessed at four to eight weeks. Maintenance medical therapy should be at the lowest dose and frequency necessary to maintain symptom relief; antireflux surgery is an alternative for a small proportion of selected patients. Routine testing for Helicobacter pylori infection is unnecessary before starting GERD therapy. GERD is associated with Barrett's epithelium and esophageal adenocarcinoma but the risk of malignancy is very low. Endoscopic screening for Barrett's epithelium may be considered in adults with GERD symptoms for more than 10 years; Barrett's epithelium and low-grade dysplasia generally warrant surveillance; endoscopic or surgical management should be considered for confirmed high-grade dysplasia or malignancy. CONCLUSION: Prospective studies are needed to investigate clinically relevant risk factors for the development of GERD and its complications; GERD progression, on and off therapy; optimal management strategies for typical GERD symptoms in primary care patients; and optimal management strategies for atypical GERD symptoms, Barrett's epithelium and esophageal adenocarcinoma.     

Failure of Initial 24-Hour Esophageal pH Monitoring to Predict Refractoriness and Intractability in Reflux Esophagitis

Prolonged esophageal pH monitoring is considered to be the most sensitive and specific test for the diagnosis of gastroesophageal reflux disease (GERD). However, the role of pH monitoring in predicting the clinical and endoscopic response of reflux esophagitis is not well defined. In this study, 106 patients with moderate to severe symptoms of GERD and esophagitis (grades 0-IV) by endoscopy were initially studied by ambulatory esophageal pH monitoring, and their clinical response to standard H2 antagonist therapy was monitored at 8 wk. Refractory patients were defined as those who failed to heal and/or had intractable reflux symptoms after 8 wk of H2 antagonist therapy, and who required continuous therapy with higher doses of H2 antagonists, addition of prokinetic agents, or omeprazole. There was a positive correlation (r = 0.89) between endoscopic severity of esophagitis upon entry into the study and refractoriness to standard medical therapy. However, there were no differences in the various pH parameters analyzed between the 58 patients who responded and the 48 patients who were refractory to medical therapy, regardless of the endoscopic grading of their esophagitis. We conclude that 24-h ambulatory esophageal pH monitoring does not predict refractoriness of reflux esophagitis to standard therapy. The decision for more aggressive methods of treatment probably requires assessment of symptomatic and endoscopic response after 8 week standard H2 antagonist therapy.     

Medical Therapy of Cushing's Disease

Surgical excision of an ACTH-producing pituitary tumor is the optimal therapy for Cushing's disease. However, medical therapy may have either a primary or adjunctive role if the patient cannot safely undergo surgery, if surgery fails, or if the tumor recurs. When medication is the only therapy, a major disadvantage is the need for lifelong therapy; in general, recurrence follows discontinuation of treatment. These compounds work through three broad mechanisms of action. Neuromodulatory compounds modulate corticotropin (ACTH) release from a pituitary tumor, steroidogenesis inhibitors reduce cortisol levels by adrenolytic activity and/or direct enzymatic inhibition and glucocorticoid antagonists block cortisol action at its receptor.In general, neuromodulatory compounds (bromocriptine, cyproheptidine, somatostatin and valproic acid) are not very effective agents for Cushing's disease. Treatment with a glucocorticoid antagonist and radiation therapy has been reported on a single patient only. Steroidogenesis inhibitors, including mitotane, metyrapone, ketoconazole, and aminoglutethimide, are the agents of choice for medical therapy of Cushing's disease. In general, ketoconazole is the best tolerated of these agents and is effective as monotherapy in about 70% of patients. Mitotane and metyrapone may be effective as single agents, while aminoglutethimide generally must be given in combination. The intravenously-administered etomidate may used when patients cannot take medications by mouth.     

Principes thérapeutiques du reflux gastroœsophagien

Gastroesophageal reflux is a common disease. Its chronic course, even if mild, is sometimes complicated by erosive oesophagitis. Drug therapy acts against gastric acidity and motility disorders. Treatment of gastroesophageal reflux disease has three aims: improvement of symptoms and quality of life, healing erosive lesions and prevention of symptomatic and endoscopie relapses. Non-drug measures are always useful, even if their efficacy is not well established. Initial therapy of a symptomatic reflux or mild oesophagitis is most of the time effective (antacids, prokinetics, H₂ receptor antagonists). Proton-pump inhibitors are also effective in healing and preventing severe oesophagitis. Questions about long-term treatment adverse events with powerful acid inhibitors, such as hypergastrinemia and the risk of gastric carcinoid tumours seem to be resolved. Studies are requested to define the optimal long-term maintenance treatment with cisapride, H₂ receptor antagonists or proton-pump inhibitors at low doses in prevention of symptomatic and mild oesophagitis relapses.     

Importance of pH control in the management of GERD

The degree of esophageal mucosal injury that occurs in patients with gastroesophageal reflux disease depends on duration of exposure and pH of the refluxate. Evidence suggests that an intraesophageal pH of less than 4.0 directly correlates with the degree of mucosal injury. The advent of acid secretory inhibitors such as the histamine2-receptor antagonists (H2RAs) and, more recently, the proton pump inhibitors (PPIs) has revolutionized the treatment of patients with reflux disease. However, the evidence linking the degree of mucosal damage to pH of the refluxate has prompted investigators to reevaluate the effectiveness of these agents. The PPIs are significantly more effective than the H2RAs in achieving and sustaining an intragastric pH above 4.0. The results of clinical trials performed with the PPIs indicate a faster rate of healing of erosive esophagitis and of symptom relief than treatment with H2RAs.     

Ultrasonographic evaluation of lansoprazole-induced improvement of submucosal injury in patients with gastroesophageal reflux

OBJECTIVE: Endoscopic ultrasonographic (EUS) changes in gastroesophageal reflux disease (GERD) after treatment with proton pump inhibitor have been poorly evaluated. We conducted a randomized, double-blind 12-wk clinical trial to compare the EUS effects of lansoprazole to histamine H2-receptor antagonist therapy in GERD. METHODS: Seventeen patients with reflux-related symptoms received 40 mg of famotidine for 6 wk or 30 mg of lansoprazole for 6 wk followed by 40 mg of famotidine or 30 mg of lansoprazole for another 6 wk, respectively. Patients underwent EUS before and at 6 and 12 wk after treatment. RESULTS: Before treatment, a variable degree of wall thickening was noted on EUS in the lower esophagus, compared with 20 normal subjects. After 6 wk of therapy, esophageal wall was significantly thicker in the famotidine group compared with the lansoprazole group (p<0.01). Surprisingly, thickening of esophageal wall and abnormal architecture were also detected in endoscopically negative reflux disease. Lansoprazole was superior to famotidine in reducing the thickness of esophageal wall. CONCLUSIONS: EUS was very useful for evaluation of submucosal injury in patients with GERD. EUS showed that a 6-wk course of lansoprazole therapy reduced thickening of esophageal wall, which was resistant to histamine H2-receptor antagonist therapy. Our results also suggest that inflammatory damage to the submucosal and muscle layers of the lower esophagus is the underlying mechanism of heartburn and associated symptoms in patients with endoscopically negative reflux disease.     

Strategies for medical management of reflux disease.

Management of gastro-oesophageal reflux disease (GORD) patients must consider two issues: (i) how to optimize the treatment of a presenting symptom complex, and (ii) how to manage risk of adenocarcinoma associated with GORD. In most cases the need for, and potency of, pharmacological therapy used is decided by symptom assessment. Considering cost effectiveness, the three increments of pharmacological therapy are: (i) generic histamine(2)receptor antagonists, (ii) standard dose proton pump inhibitors, and (iii) higher dose proton pump inhibitors. Endoscopy is warranted if there is doubt regarding the diagnosis of GORD or if the patient relays alarm symptoms suggesting more ominous diagnoses (dysphagia, bleeding, weight loss, odynophagia). The other major indication for endoscopy is to screen for adenocarcinoma or Barrett's metaplasia in the patient with chronic symptoms. In most patients, the need for maintenance medical therapy is determined by the rapidity of symptom recurrence during a trial period off the medication.     

Long-term management of GERD in the elderly with pantoprazole

The prevalence of gastroesophageal reflux disease (GERD) increases with age and elderly are more likely to develop severe disease. Older patients often complain of less severe or frequent heartburn than younger patients and they may present with atypical symptoms such as dysphagia, weight loss, or extraesophageal symptoms. Proton pump inhibitors (PPIs) are central in the management of GERD and are unchallenged with regards to their efficacy. They are considered safe and more effective than histamine receptor antagonists for healing esophagitis and for preventing its recurrence using a long term maintenance treatment. PPI have minimal side effects and few slight drug interactions and are considered safe for long term treatment. Pantoprazole is significantly effective both for acute and long-term treatment with excellent control of relapse and symptoms. It is well tolerated even for long-term therapy and its tolerability is optimal. Pantoprazole shows to have minimal interactions with other drugs because of a lower affinity for cytocrome P450 than older PPIs. Although the majority of elderly has concomitant illnesses and receive other drugs, this does not adversely effect the efficacy of pantoprazole because of its pharmacokinetics, which are independent of patient age. Clinical practice suggests that a low dose maintenance of PPIs should be used in older patients with GERD.     

Regression of melanoma nodules in a patient treated with ranitidine

Human malignant melanoma may regress spontaneously or with immunotherapy, such as Calmette-Guerin bacillus, interferon alfa, interleukin-2, and interleukin-2 plus lymphokine-activated killer cells. Histamine type 2 receptor antagonists can modulate immune function by inhibiting suppressor T-cell induction and activity, and melanoma regressions have been reported after the use of cimetidine with coumarin or interferon alfa. This article describes the complete regression of melanoma nodules in a patient treated with ranitidine hydrochloride, another histamine type 2-receptor antagonist. Ranitidine and cimetidine should be considered to be possibly active immunotherapeutic agents in the design and evaluation of clinical trials.     

Evolving therapeutic strategies for retarding progression of diabetic nephropathy - an update for 2002

During the past few years, several major intervention trials have been conducted in an attempt to determine the efficacy of specific antihypertensive agents in retarding progression of diabetic nephropathy. These studies have clearly demonstrated the importance of renin-angiotensin system blockade in attenuating progressive renal disease. The preferred initial therapy is an angiotensin-converting enzyme (ACE) inhibitor, or an angiotensin type 1 (AT₁) receptor antagonist based on the recent 'landmark' proof-of-concept trials - the Irbesartan Type 2 Diabetic Nephropathy Trial (IDNT) and the Reduction of Endpoints in NIDDM with Angiotensin II Antagonist Losartan (RENAAL). However, these clinical trials also demonstrate that aggressive blood pressure targets are needed in patients with diabetes and hypertension. This frequently requires multiple-drug therapy with several different classes of antihypertensive agents. Data from several clinical trials, including RENAAL, suggest that calcium antagonists may be added to ACE inhibitor or AT₁ receptor antagonist therapy as needed to achieve target blood pressure. Calcium antagonists could, therefore, constitute an important component of the antihypertensive regimen in the management of patients with diabetic nephropathy.     

Angiotensin II receptor antagonists in arterial hypertension

Angiotensin II receptor antagonists (AT-1) represent a new group of orally active antihypertensive agents. Activation on AT-1 receptor leads to vasoconstriction, stimulation of the release of catecholamines and antidiuretic hormone with production of thirst, and promote growth of vascular and cardiac muscle; these effects are blocked by AT-1 antagonist agents. The first chemically useful, orally active AT-1 receptor antagonist was losartan, followed by other agents currently in clinical use, such as: valsartan, eprosartan, irbesartan, telmisartan, candesartan, and many others under investigation. AT-1 receptor antagonists are effective in reducing high blood pressure in hypertensive patients. Monotherapy in mild to moderate hypertension controls blood pressure in 40 to 50% of these patients; when a low dose of a thiazide diuretic is added, 60 to 70% of patients are controlled. The efficacy is similar to angiotensin-converting enzyme inhibitors, diuretics, calcium antagonists and beta-blocking agents. Tolerability has been reported to be very good. AT-1 receptor antagonists would be a drug of choice in otherwise well-controlled hypertensive patients treated with angiotensin-converting enzyme inhibitors who developed cough or angioedema. The final position in the antihypertensive therapy in this special population and other clinical situations, such as left ventricular hypertrophy, heart failure, diabetes mellitus and renal disease, has to be determined in large prospective clinical trials, some of which are now being conducted.     

Esophageal pharmacology and treatment of primary motility disorders

Swallowing is a complex mechanism based on the coordinated collaboration of tongue, pharynx and esophagus. Disturbances of this interplay or disorders of one or several of these components lead to dysphagia, non-cardiac chest pain or regurgitation. The major primary esophageal motility disorders--achalasia, diffuse esophageal spasm, hypercontractile esophagus ('nutcracker esophagus') and non-specific motility disorder--are of unknown etiology. Other esophageal diseases, such as cervical diverticula or gastroesophageal reflux disease, might also be caused by a primary esophageal motility disorder. Medical treatment of esophageal disorders with esophageal hyper- or dysmotility requires agents that reduce esophageal contractile force (anticholinergic agents, nitrates, calcium antagonists). Despite the beneficial effect of the various drugs on esophageal motility parameters, the clinical benefit of medical treatment of esophageal motility disorders is rather disappointing. Calcium channel antagonist, alone or in combination with anticholinergics or nitrates, can be used as a medical trial, especially in mild achalasia. However, medical therapy is clearly inferior to pneumatic balloon dilation therapy. Recently, botulinum toxin injection was suggested as a therapeutic option in achalasia patients with good results on lower esophageal sphincter pressure (LESP) and symptom scores that were similar to the results achieved by pneumatic balloon dilation. Hypercontractile esophagus shows a good manometric response to calcium channel antagonists, but only little clinical effect in terms of improvement of symptoms. Diffuse esophageal spasm is a relatively rare disease and few clinical studies are available. The use of calcium channel antagonists can be beneficial, at least in some patients with diffuse esophageal spasm. From clinical and epidemiological studies, there is some evidence of a 'psychological' component in the pathogenesis or perception of esophageal symptoms. There is some clinical benefit from centrally acting drugs such as benzodiazepines or antidepressants. With the exception of botulinum toxin for achalasia, medical therapy of primary esophageal motility disorders is rather limited and the clinical results are poor. Further understanding of esophageal pathophysiology as well as development of new receptor-selective drugs might increase our chances of a successful treatment of primary esophageal motility disorders.     

The 2004 Canadian recommendations for the management of hypertension: Part II--Therapy

OBJECTIVE: To provide updated, evidence-based recommendations for the management of hypertension in adults. OPTIONS AND OUTCOMES: For patients who require pharmacological therapy for hypertension, a number of antihypertensive agents may be used. Randomized trials evaluating first-line therapy with diuretics, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, calcium channel blockers (CCBs), alpha-blockers, centrally acting agents or angiotensin receptor antagonists were reviewed. Also, randomized trials evaluating other agents, such as statins or acetylsalicylic acid, in patients with hypertension were reviewed. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. In addition, other relevant outcomes such as development of end-stage renal disease or changes in blood pressure were examined where appropriate. EVIDENCE: MEDLINE searches were conducted from November 2001 to October 2003 to update the 2001 Recommendations for the management of hypertension. Reference lists were scanned, experts were contacted, and the personal files of the subgroup members and authors were used to identify additional published studies. All relevant articles were reviewed and appraised independently, using prespecified levels of evidence by content and methodology experts. RECOMMENDATIONS: This document contains detailed recommendations and supporting evidence on treatment thresholds, target blood pressures and choice of agents for hypertensive patients with or without comorbidities. Lifestyle modifications are a key component of any antiatherosclerotic management strategy and detailed recommendations are contained in a separate document. Key recommendations for pharmacotherapy include the following: treatment thresholds and targets should take into account each individual's global atherosclerotic risk, target organ damage and comorbidities, with particular attention to systolic blood pressure; blood pressure should be lowered to 140/90 mmHg or less in all patients, and 130/80 mmHg or less in those with diabetes mellitus or renal disease (125/75 mmHg or less in those with nondiabetic renal disease and more than 1 g of proteinuria per day); most adults with hypertension require more than one agent to achieve target blood pressures; for adults without compelling indications for other agents, initial therapy should include thiazide diuretics; other agents appropriate for first-line therapy for diastolic hypertension with or without systolic hypertension include beta-blockers (in those younger than 60 years), ACE inhibitors (in non-Blacks), long-acting dihydropyridine CCBs or angiotensin receptor antagonists; other agents appropriate for first-line therapy for isolated systolic hypertension include long-acting dihydropyridine CCBs or angiotensin receptor antagonists; certain comorbidities provide compelling indications for first-line use of other agents: in patients with angina, recent myocardial infarction or heart failure, beta-blockers and ACE inhibitors are recommended as first-line therapy; in patients with diabetes mellitus, ACE inhibitors or angiotensin receptor antagonists (or thiazides in patients with diabetes mellitus without albuminuria) are appropriate first-line therapies; and in patients with mild to moderate nondiabetic renal disease, ACE inhibitors are recommended; all hypertensive patients should have their fasting lipids screened and those with dyslipidemia should be treated using the thresholds, targets and agents as per the Recommendations for the management of dyslipidemia and the prevention of cardiovascular disease; and selected patients with hypertension should also receive statin and/or acetylsalicylic acid therapy. VALIDATION: All recommendations were graded according to the strength of the evidence and voted on by the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. Individuals with irreconcilable competing interests (declared by all members, compiled and circulated before the meeting) relative to any specific recommendation were excluded from voting on that recommendation. Only recommendations achieving at least 70% consensus are reported here. These guidelines will continue to be updated annually.     

Current and future treatment of chest pain of presumed esophageal origin

Patients with chest pain of presumed esophageal origin should be reassured and should undergo an esophageal manometry study. In patients with spastic esophageal disorders, a trial with calcium channel blockers or low-dose antidepressants used as visceral analgesics is the best approach. Inpatients with non GERD-related, nonspastic esophageal motility disorder, low-dose antidepressants seem reasonable. Anxiolytics are useful in patients with panic disorders, and psychological interventions (eg, cognitive-behavioral therapy) are also valuable, mainly in patients in whom reassurance is not sufficient to avoid the misinterpretation of their symptoms. In the future, visceral sensitivity modifying agents such as serotoninergic agonists or antagonists may become the cornerstone of therapy in patients with chest pain of presumed esophageal origin.Combinations of different approaches, such as proton pump inhibitors and psychotropic or antinociceptive agents, should also be evaluated in clinical trials.     

Histamine receptors in esophageal smooth muscle of the opossum.

Esophageal smooth muscle was examined for histamine receptors. The effects of histamine, the histamine analogs 4-methylhistamine (4-MH) and 2-(2-pyridyl) ethylamine (PEA), the histamine receptor antagonists mepyramine and metiamide, and the histamine-releasing substance compound 48/80, on lower esophageal sphincter (LES) and esophageal body (EB) smooth muscle of the opossum were studied in a superfused tissue bath. Histamine, PEA, an H1 receptor agonist, and compound 48/80 caused a dose-related increase in LES basal tension and in EB off response amplitude, the threshold for histamine being 6.7 X 10(-8) M and that for PEA being 6.7 X 10(-7) M. In the presence of mepyramine, and H1 receptor antagonist, the effects of histamine and compound 48/80 were reversed to inhibition of both LES basal tension and EB off response amplitude, while the effect of PEA was abolished. Metiamide, an H2 receptor antagonist, did not alter responses to histamine, PEA, or compound 48/80. The H2 receptor agonist 4-methylhistamine caused a reduction of LES tension and EB off response amplitude, but caused an increase in those parameters in the presence of metiamide. A combination of mepyramine and metiamide abolished responses to all agonist drugs. The results indicate that LES and EB smooth muscle contain both excitatory H1 and inhibitory H2 receptors for histamine. Endogenous histamine released from storage sites in LES and EB and exogenous histamine both preferentially activate H1 receptors.     

Management of hypertension and heart failure in patients with Addison's disease

Addison's disease may be complicated by hypertension and less commonly by heart failure. We review the pathophysiology of the renin‐angiotensin‐aldosterone axis in Addison's disease and how this is altered in the setting of hypertension and heart failure. An essential first step in management in both conditions is optimizing glucocorticoid replacement and considering dose reduction if excessive. Following this, if a patient with Addison's disease remains hypertensive, the fludrocortisone dose should be reviewed and reduced if there are clinical and/or biochemical signs of mineralocorticoid excess. In the absence of such signs, where the renin is towards the upper end of the normal range or elevated, an angiotensin II (AII) receptor antagonist or angiotensin converting enzyme (ACE) inhibitor is the treatment of choice, and the fludrocortisone dose should remain unchanged. Dihydropyridine calcium channel blockers are clinically useful as second line agents, but diuretics should be avoided. In the setting of heart failure, there is an increase in total body sodium and water; therefore, it is appropriate to reduce and rarely consider ceasing the fludrocortisone. Loop diuretics may be used, but not aldosterone antagonists such as spironolactone or eplerenone. Standard treatment with ACE inhibitors, or as an alternative, AII receptor antagonists, are appropriate. Measurements of renin are no longer helpful in heart failure to determine the volume status but plasma levels of brain natriuretic peptide (BNP/proBNP) may help guide therapy.