Adverse reactions with angiotensin converting enzyme (ACE) inhibitors

An analysis combining proteomics and transcriptomics revealed a regulation target of sea cucumber autolysis

Sea cucumber is a valuable seafood product and autolysis is the main concern for the aquaculture industry. This study employed proteomics and transcriptomics to investigate the autolysis mechanism of sea cucumbers. The fresh sea cucumber was exposed to UV light to induce autolysis. The body wall samples were cut off to analyze by proteomics and transcriptomics. The angiotensin-converting enzyme (ACE) inhibitor of teprotide and the activator of imatinib were gastric gavage to live sea cucumbers, respectively, to identify the regulation target. Autolysis occurrence was evaluated by appearance, soluble peptide, and hydroxyproline content. Four gene-protein pairs were ACE, AJAP10923, Heme-binding protein 2-like, and Ficolin-2-like. Only the ACE protein and gene changed synchronously and a significant down-regulation of ACE occurred in the autolysis sea cucumbers. Teprotide led to a 1.58-fold increase in the TCA-soluble protein content and a 1.57-fold increase in hydroxyproline content. No significant differences were observed between imatinib-treated sea cucumbers and fresh ones regarding TCA-soluble protein content or hydroxyproline levels (P > 0.05). ACE inhibitor accelerated the autolysis of sea cucumber, but ACE activator inhibited the autolysis. Therefore, ACE can serve as a regulatory target for autolysis in sea cucumbers.

Transformation of peptides to small molecules in medicinal chemistry: Challenges and opportunities

Peptides are native binders involved in numerous physiological life procedures, such as cellular signaling, and serve as ready-made regulators of biochemical processes. Meanwhile, small molecules compose many drugs owing to their outstanding advantages of physiochemical properties and synthetic convenience. A novel field of research is converting peptides into small molecules, providing a convenient portable solution for drug design or peptidomic research. Endowing properties of peptides onto small molecules can evolutionarily combine the advantages of both moieties and improve the biological druggability of molecules. Herein, we present eight representative recent cases in this conversion and elaborate on the transformation process of each case. We discuss the innovative technological methods and research approaches involved, and analyze the applicability conditions of the approaches and methods in each case, guiding further modifications of peptides to small molecules. Finally, based on the aforementioned cases, we summarize a general procedure for peptide-to-small molecule modifications, listing the technological methods available for each transformation step and providing our insights on the applicable scenarios for these methods. This review aims to present the progress of peptide-to-small molecule modifications and propose our thoughts and perspectives for future research in this field.

Stevens-Johnson Syndrome From Combined Allopurinol and Angiotensin-Converting Enzyme Inhibitors: A Narrative Review

Stevens-Johnson syndrome (SJS) is a severe and potentially debilitating skin reaction frequently related to medication use. Allopurinol and angiotensin-converting enzyme (ACE) inhibitors are commonly prescribed medications for prevalent health conditions worldwide, and their interaction associated with SJS warrants further investigation. A comprehensive literature search was performed to investigate cases as studies related to SJS occurring in patients with concomitant use of allopurinol and ACE inhibitors. We identified case reports and studies detailing hypersensitivity reactions, including SJS, attributed to a combination of allopurinol and ACE inhibitors. Despite the drug-drug interactions or lack thereof seen in patient populations, there is no definitive evidence of a pharmacokinetic interaction between allopurinol and ACE inhibitors. We were only able to find one case report specifically detailing SJS in a patient on combined ACE inhibitors and allopurinol. While the exact mechanism of the interaction is unclear, those reported cases of severe hypersensitivity reactions suggest a previous history of impaired renal function as a predisposing factor in the development of SJS. The potential risk of SJS with coadministration of ACE inhibitors and allopurinol is a drug-drug interaction that physicians should be aware of. This topic requires additional attention to determine if this drug combination should be avoided entirely in certain patients.

The contribution of the AT1 receptor to erythropoiesis

The renin-angiotensin system (RAS) comprises a broad set of functional peptides and receptors that play a role in cardiovascular homeostasis and contribute to cardiovascular pathologies. Angiotensin II (Ang II) is the most potent peptide hormone produced by the RAS due to its high abundance and its strong and pleiotropic impact on the cardiovascular system. Formation of Ang II takes place in the bloodstream and additionally in tissues in the so-called local RAS. Of the two Ang II receptors (AT1 and AT2) that Ang II binds to, AT1 is the most expressed throughout the mammalian body. AT1 expression is not restricted to cells of the cardiovascular system but in fact AT1 protein is found in nearly all organs, hence, Ang II takes part in several modulatory physiological processes one of which is erythropoiesis. In this review, we present multiple evidence supporting that Ang II modulates physiological and pathological erythropoiesis processes trough the AT1 receptor. Cumulative evidence indicates that Ang II by three distinct mechanisms influences erythropoiesis: 1) stimulation of renal erythropoietin synthesis; 2) direct action on bone marrow precursor cells; and 3) modulation of sympathetic nerve activity to the bone marrow. The text highlights clinical and preclinical evidence focusing on mechanistic studies using rodent models.

Hematologic adverse drug reactions leading to hospitalization among cancer patients: A retrospective case-control study

BACKGROUND

Cancer is one of the leading causes of death worldwide. Despite the rapid evolution of cancer treatment, chemotherapy remains the mainstay in the management of cancer. Chemotherapy can result in various adverse drug reactions (ADRs), which may lead to hospitalization and even life-threatening side-effects. Hematologic ADRs are among the most severe forms of ADR following chemotherapy, as they generally lead to hospitalization. It is important to realize the predictors and outcome of hematologic ADRs in cancer patients.

METHODS

We conducted a hospital-based case-control study to include all the cancer patients who were hospitalized to receive chemotherapy in Taipei Veterans General Hospital during 2013. Among them the patients rehospitalized after chemotherapy due to neutropenia, leucopenia, or pancytopenia were identified as the study group. Control subjects consisted of hospitalized cancer patients who did not display the aforementioned ADRs. The study and control groups were numbered in the ratio of 1:4 and were age- and gender-matched. Their demographic and clinical characteristics were collected through chart review. Determinants of hematologic ADRs were then analyzed.

RESULTS

During the study period, we collected a total of 64 patients into the study group and 256 as control subjects. The mean length of hospitalization was 11 days in the study group of patients, which was 5 days longer than that in the control group (p < 0.001). Predictors of hematologic ADR-related hospitalization included history of hematologic ADRs, hypertension, cisplatin treatment, and a Charlson comorbidity score of 2 to 3.

CONCLUSION

Severe outcomes of hematologic ADRs may increase healthcare costs and decrease patient productivity. Therefore, the determinants of ADR-related hospitalization identified in this study may help improve the quality of healthcare for cancer patients.

A Comparison of the Effect of Enalapril and Metoprolol on Renal Function, Potassium Balance, Lipid Profile, Cardiac Function, Exercise Tolerance and Quality of Life in Hypertensive Dialysis Patients

26 patients with hypertension while on hemodialysis or continuous ambulatory peritoneal dialysis for end-stage renal diseases were treated first with enalapril and then changed to metoprolol. Both drugs were shown to be similarly effective in controlling blood pressure. There was no difference between the two drugs in their effects on renal function, potassium balance, lipid profile, cardiac function, exercise tolerance, and quality of life. Mild worsening of anemia was observed during treatment with enalapril. No serious side effects were reported. Use of enalapril is safe in the treatment of hypertension in dialysis patients.

Vasodilator and hypotensive effects of the spider peptide Lycosin-I in vitro and in vivo

Lycosin-I, a spider peptide isolated from the venom of the spider Lycosa singoriensis, has anti-bacteria and anti-cancer properties in organisms. However, cardiovascular effects of Lycosin-I have not been studied. In this study, we investigated for the first time the vasodilator and hypotensive effects of Lycosin-I and the possible mechanisms, in order to develop a promising treatment for hypertension-related diseases. For in vitro experiments, thoracic aortas were isolated, and divided into two groups, endothelium-intact and endothelium-denuded aortic rings. Lycosin-I induced a remarkable dose-dependent relaxation in endothelium-intact aortic rings pre-treated with phenylephrine (p < 0.05), while it showed no obvious vasodilator effects in endothelium-denuded aortic rings (p > 0.05). The vasodilator effects of Lycosin-I were significantly weakened by a nitric oxide synthase (NOS) inhibitor, L-NAME (p < 0.001) and a selective inhibitor of nitric oxide (NO)-sensitive soluble guanylate cyclase (sGC), ODQ (p < 0.05), respectively. The levels of endothelial nitric oxide synthase (eNOS) phosphorylation and the NO production were significantly higher in human umbilical vascular endothelial cells pre-cultured with Lycosin-I than the control (p < 0.001), determined via western blot analysis and ozone-chemiluminescence technology. For in vivo experiments, arterial and venous catheters were inserted for mean arterial pressure (MAP) recording and drug administration in anaesthetized spontaneously hypertensive rats. Lycosin-I caused a transient drop of MAP 2 min after the administration compared with the control (p < 0.001). In conclusion, Lycosin-I has the potential to be an anti-hypertensive drug by endothelium-dependent vasodilatation, in which eNOS and NO-sensitive sGC are two main involved factors.

Synergistic inhibition of angiogenesis by artesunate and captopril in vitro and in vivo

Inhibition of angiogenesis represents one major strategy of cancer chemotherapy. In the present investigation, we investigated the synergism of artesunate and captopril to inhibit angiogenesis. Artesunate is an antimalarial derivative of artemisinin from the Chinese medicinal plant, Artemisia annua L., which also reveals profound anticancer activity in vitro and in vivo. Captopril is an angiotensin I-converting (ACE) inhibitor, which is well established in Western academic medicine. Both compounds inhibited migration of human umbilical vein endothelial cells (HUVECs) in vitro. The combination of both drugs resulted in synergistically inhibited migration. Whereas artesunate inhibited HUVEC growth in the XTT assay, captopril did not, indicating independent modes of action. We established a chorioallantoic membrane (CAM) assay of quail embryos (Coturnix coturnix L.) and a computer-based evaluation routine for quantitative studies on vascularization processes in vivo. Artesunate and captopril inhibited blood vessel formation and growth. For the first time, we demonstrated that both drugs revealed synergistic effects when combined. These results may also have clinical impact, since cardiovascular diseases and cancer frequently occur together in older cancer patients. Therefore, comorbid patients may take advantage, if they take captopril to treat cardiovascular symptoms and artesunate to treat cancer.

Drugs from slugs. Part II--conopeptide bioengineering

The biological transformation of toxins as research probes, or as pharmaceutical drug leads, is an onerous and drawn out process. Issues regarding changes to pharmacological specificity, desired potency, and bioavailability are compounded naturally by their inherent toxicity. These often scuttle their progress as they move up the narrowing drug development pipeline. Yet one class of peptide toxins, from the genus Conus, has in many ways spearheaded the expansion of new peptide bioengineering techniques to aid peptide toxin pharmaceutical development. What has now emerged is the sequential bioengineering of new research probes and drug leads that owe their lineage to these highly potent and isoform specific peptides. Here we discuss the progressive bioengineering steps that many conopeptides have transitioned through, and specifically illustrate some of the biochemical approaches that have been established to maximize their biological research potential and pharmaceutical worth.

The importance of renin-angiotensin blockade in patients with cardio-renal disease

The existence of the renin-angiotensin-aldosterone system was first postulated over 100 years ago. Following the identification of all the major components, came the discovery of their potential pathogenicity in cardiovascular and renal disease. The introduction of drugs that inhibit the synthesis or actions of this system has prompted a number of trials that have largely shaped how cardiovascular and renal disease is managed today. The continued discovery of yet more components of this system promises to further our understanding of its influence on disease processes and herald the development of more highly selective drugs, ensuring that the renin-angiotensin-aldosterone system will continue to be a key area of interest for many years to come.

Reinventing the ACE inhibitors: some old and new implications of ACE inhibition

Since their inception, angiotensin-converting enzyme (ACE) inhibitors have been used as first-line therapy for the treatment of cardiovascular and renal diseases. They restore the balance between the vasoconstrictive salt-retentive and hypertrophy-causing peptide angiotensin II (Ang II) and bradykinin, a vasodilatory and natriuretic peptide. As ACE is a promiscuous enzyme, ACE inhibitors alter the metabolism of a number of other vasoactive substances. ACE inhibitors decrease systemic vascular resistance without increasing heart rate and promote natriuresis. They have been proven effective in the treatment of hypertension, and reduce mortality in congestive heart failure and left ventricular dysfunction after myocardial infarction. They inhibit ischemic events and stabilize plaques. Furthermore, they delay the progression of diabetic nephropathy and neuropathy and act as antioxidants. Ongoing studies have elucidated protective roles for them in both memory-related disorders and cancer. Lastly, N- and C-domain selective ACE inhibitors have led to new uses for ACE inhibitors.

Outbreak of acute renal failure in Panama in 2006: a case-control study

OBJECTIVE

In September 2006, a Panamanian physician reported an unusual number of patients with unexplained acute renal failure frequently accompanied by severe neurological dysfunction. Twelve (57%) of 21 patients had died of the illness. This paper describes the investigation into the cause of the illness and the source of the outbreak.

METHODS

Case-control and laboratory investigations were implemented. Case patients (with acute renal failure of unknown etiology and serum creatinine > 2 mg/dl) were individually matched to hospitalized controls for age (+/- 5 years), sex and admission date (< 2 days before the case patient). Questionnaire and biological data were collected. The main outcome measure was the odds of ingesting prescription cough syrup in cases and controls.

FINDINGS

Forty-two case patients and 140 control patients participated. The median age of cases was 68 years (range: 25-91 years); 64% were male. After controlling for pre-existing hypertension and renal disease and the use of angiotensin-converting enzyme inhibitors, a significant association was found between ingestion of prescription cough syrup and illness onset (adjusted odds ratio: 31.0, 95% confidence interval: 6.93-138). Laboratory analyses confirmed the presence of diethylene glycol (DEG) in biological samples from case patients, 8% DEG contamination in cough syrup samples and 22% contamination in the glycerin used to prepare the cough syrup.

CONCLUSION

The source of the outbreak was DEG-contaminated cough syrup. This investigation led to the recall of approximately 60 000 bottles of contaminated cough syrup, widespread screening of potentially exposed consumers and treatment of over 100 affected patients.

A Review of the Structural and Functional Features of Olmesartan Medoxomil, An Angiotensin Receptor Blocker

The angiotensin II (A-II) type 1 (AT1) receptor-mediated effects of A-II play a key role in the pathophysiology of hypertension. Effective inhibition of A-II is provided by the latest class of antihypertensive medications, the AT1 receptor blockers (ARBs). These orally available agents were developed around a common imidazole-based structural core. The most recent member of this drug class to be approved by the Food and Drug Administration, olmesartan medoxomil, contains unique features that may explain its clinical efficacy. Key structural elements of olmesartan medoxomil include a hydroxyalkyl substituent at the imidazole 4-position and a hydrolyzable ester group at the imidazole 5-position. Inter- and intramolecular hydrogen bonding involving these groups may contribute to the potentiation of antagonist activity. After oral administration, olmesartan medoxomil is deesterified in the intestinal tract to produce the active metabolite olmesartan, which undergoes no additional metabolic change. The marked antihypertensive efficacy of olmesartan medoxomil may result from a unique pharmacological interaction of the drug with the AT1 receptor, resulting in a potent, long-lasting, dose-dependent blockade of A-II. This review article characterizes the structural features of olmesartan that may be responsible for its clinical efficacy. Inferential pharmacological studies compare and contrast the effects of olmesartan to those of other ARBs in comparable preclinical animal models.

Angiotensin-converting enzyme inhibitors

ACE inhibitors have achieved widespread usage in the treatment of cardiovascular and renal disease. ACE inhibitors alter the balance between the vasoconstrictive, salt-retentive, and hypertrophic properties of angiotensin II (Ang II) and the vasodilatory and natriuretic properties of bradykinin and alter the metabolism of a number of other vasoactive substances. ACE inhibitors differ in the chemical structure of their active moieties, in potency, in bioavailability, in plasma half-life, in route of elimination, in their distribution and affinity for tissue-bound ACE, and in whether they are administered as prodrugs. Thus, the side effects of ACE inhibitors can be divided into those that are class specific and those that relate to specific agents. ACE inhibitors decrease systemic vascular resistance without increasing heart rate and promote natriuresis. They have proved effective in the treatment of hypertension, they decrease mortality in congestive heart failure and left ventricular dysfunction after myocardial infarction, and they delay the progression of diabetic nephropathy. Ongoing studies will elucidate the effect of ACE inhibitors on cardiovascular mortality in essential hypertension, the role of ACE inhibitors in patients without ventricular dysfunction after myocardial infarction, and the role of ACE inhibitors compared with newly available angiotensin AT1 receptor antagonists.

ACE-inhibitor-induced cough, an adverse drug reaction unrecognised for several years: studies in prescription-event monitoring

OBJECTIVE. This study examines cough recorded in Prescription-Event Monitoring (PEM) of four ACE-inhibitors. Particular attention was paid to the study of enalapril because the drug was monitored before the causal relationship between cough and ACE-inhibitors had been widely accepted. RESULTS. Several factors which had obscured the causal relationship in the individual cases were found to be also an obstacle in PEM. For example, cough was a common and non-serious event and was under-reported in the PEM study of enalapril and the rate was not strikingly different from that recorded for other drugs. Cough induced by ACE-inhibitors has several characteristics which reduce the chance of a recognisable "signal'. The original questionnaires returned from doctors in the PEM study of enalapril have been reexamined. The observation that the rate of cough diminished after enalapril had been stopped rather than increased after starting, provided the best evidence of causality, because this was not affected by many biases such as the publicity that had occurred prior to doctors participating in PEM completed later reports.

Hospitalized congestive heart failure patients with preserved versus abnormal left ventricular systolic function: clinical characteristics and drug therapy

PURPOSE

To compare clinical characteristics of and pharmacologic therapy for hospitalized patients with congestive heart failure (CHF) and left ventricular systolic dysfunction or normal left ventricular systolic function.

PATIENTS AND METHODS

Medical records were reviewed for all patients discharged with a principal diagnosis of CHF from a university hospital and a community hospital between September 1, 1991 and August 31, 1992. Pertinent medical history items and prescribed drug therapies at discharge were recorded for each patient's first calendar year admission. Patients were categorized as having either normal left ventricular systolic function or systolic dysfunction based on the results of echocardiography and radionuclide angiography or contrast ventriculogram.

RESULTS

Of 298 patients with CHF, 92 (31%) had normal left ventricular systolic function. Patients with normal systolic function were older, were more often women, were less likely to have a history of coronary artery disease, and were more likely to have a history of hypothyroidism than patients with systolic dysfunction. However, the prevalence of clinical characteristics overlapped considerably between the two groups. Among patients with systolic dysfunction, 79% were discharged on a therapeutic regimen of digoxin, 65% on an angiotensin-converting enzyme inhibitor, and 26% on either a beta-blocker or a calcium channel blocker. Among patients with normal systolic function, 50% were discharged on a regimen of a beta-blocker or a calcium channel blocker and 38% were discharged on digoxin. Twenty-six percent of patients with normal systolic function and without a history of atrial fibrillation were discharged on a digoxin regimen.

CONCLUSION

Hospitalized CHF patients with normal left ventricular systolic function and those with diminished left ventricular systolic function share many clinical features. Since recommended drug therapy and prognosis differ, our data underscore the importance of diagnostic testing to assess left ventricular systolic function. Drug therapy for CHF patients provides a major challenge for quality-of-care improvement.

ACE inhibitors. Drug interactions of clinical significance

ACE inhibitors are used widely in the treatment of hypertension and congestive heart failure, but there is only limited information on adverse interactions between ACE inhibitors and other cardiovascular or noncardiovascular drugs. The present article provides an overview of this issue, with emphasis on those interactions having the greatest clinical implications. In patients who have been sodium and/or volume depleted by thiazide or loop diuretics, the additional use of ACE inhibitors can lead to an excessive reduction in blood pressure and symptomatic hypotension. An increase in serum potassium levels may occur after coadministration of potassium-sparing diuretics and ACE inhibitors, resulting in hyperkalaemia especially in patients with renal insufficiency. The incidence of acute renal failure may be associated with ACE inhibitor therapy when these drugs are combined with nonsteroidal anti-inflammatory agents and given to patients whose renal function becomes increasingly dependent on angiotensin II and prostaglandins. There is some evidence, albeit scant, linking ACE inhibitors with the induction of lithium toxicity in patients maintained on lithium, and with the occurrence of severe hypersensitivity reactions in patients undergoing haemodialysis, venom immunisation or concomitant allopurinol therapy.

The expanding role of angiotensin converting enzyme inhibitors in the management of hypertension

Angiotensin converting enzyme (ACE) inhibitors are increasingly important in antihypertensive therapy because of their efficacy, tolerability, and specific benefits in subsets of patients. They are pharmacologically diverse. Whereas most benefits have been proven with older agents (captopril, enalopril), newer agents, such as benazepril, quinapril, and ramipril, offer potential advantages that remain to be proven.

Angiotensin II receptor antagonists: a new approach to blockade of the renin-angiotensin system

A-II exerts its activity on various target tissues by binding to its receptors. The discovery of local RASs and A-II receptors within various tissues has generated interest in the clinical usefulness of RAS inhibition by directly blocking the action of A-II at the receptor level. Different A-II receptor subtypes have been identified and subsequently termed AT1 and AT2. AT1-receptor subtypes are the predominant receptor subtypes existing in most organs and, by coupling to a transmembrane G protein, seem to be the main subtypes participating in the vasoactive responses of A-II. Saralasin, a peptide with specific A-II receptor-antagonistic activity, had limited practical long-term usefulness as a result of its short half-life, significant agonistic properties, and lack of oral bioavailability. The discovery of simple benzyl-substituted imidazoles, which possess weak but highly selective A-II receptor antagonistic properties, led to the development of losartan (DuP 753). Losartan is a potent, orally active, specific, competitive nonpeptide A-II receptor antagonist that appears to be an effective antihypertensive agent both in animal studies and in preliminary clinical trials. The therapeutic usefulness of losartan, however, is not limited to its antihypertensive effects. The potential benefits of A-II receptor antagonists include roles in postmyocardial infarction therapy, slowing A-II-induced cardiac hypertrophy, 154, 155 slowing the progression of heart failure, preventing postangioplasty restenosis, and in slowing the progression of renal disease. Furthermore, losartan, a selective A-II type 1 (AT1) receptor antagonist, has also been a valuable pharmacologic probe for studying the mechanism of A-II stimulation of its receptors. A-II receptor antagonism appears to be as effective as ACE inhibition in the treatment of hypertension and other pathologic processes that involve the RAS and may offer an alternative to those patients who cannot tolerate ACE inhibitors because of their side effects.

Anaphylactoid reactions associated with reuse of hollow-fiber hemodialyzers and ACE inhibitors

From July 18 through November 27, 1989, 12 anaphylactoid reactions (ARs) occurred in 10 patients at a hemodialysis center in Virginia. One patient required hospitalization; no patients died. ARs occurred within minutes of initiating dialysis and were characterized by peripheral numbness and tingling, laryngeal edema or angioedema, facial or generalized sensation of warmth, and/or nausea or vomiting. All 12 ARs occurred with dialyzers that had been reprocessed with an automated reprocessing system. A cohort study, including all patients undergoing dialysis sessions on the six days when an AR occurred, showed that the patients who experienced ARs were significantly more likely than patients who did not to be treated with angiotensin-converting enzyme (ACE) inhibitors (7/10 vs. 3/33; relative risk = 7.9; 95% confidence interval = 2.5 to 25.2) and to have been exposed to reused dialyzers rather than to new dialyzers (12/70 sessions vs. 0/31; P = 0.016). In those sessions using a reused dialyzer, the mean number of dialyzer uses in case-sessions was significantly higher than for noncase-sessions (10.3 vs. 6.2; P = 0.016). After reuse of dialyzers was discontinued at the center, no further ARs occurred, despite the continued administration of ACE inhibitors. This is the first report of an outbreak of ARs associated exclusively with reused dialyzers. We hypothesize that interactions between a dialyzer that has been repeatedly reprocessed and reused, blood, and additional factors, such as ACE inhibitors, increased the risk of developing ARs.

Anaphylactoid reactions during hemodialysis and hemofiltration: role of associating AN69 membrane and angiotensin I-converting enzyme inhibitors

Over a 20-month period, we observed 15 anaphylactoid reactions in six patients undergoing hemodialysis and three others on hemofiltration with AN69 capillary dialyzers who were receiving angiotensin-converting enzyme (ACE) inhibitors. These reactions were severe in 11 cases. In eight patients, anaphylactoid reactions stopped when AN69 membrane was replaced by polysulfone membrane and ACE inhibitors were continued. In one case, reducing the dose of ACE inhibitors was sufficient to prevent new reactions. Anaphylactoid reactions did not occur in patients undergoing dialysis with another membrane (cellulosic or synthetic), nor in those on AN69 membrane without ACE inhibitor treatment. We conclude that back-filtration of endotoxin-contaminated dialysate does not play the main role in the origin of such reactions, since they occurred in patients on hemofiltration with sterile and pyrogen-free substitution liquids.

Adverse effects of angiotensin converting enzyme (ACE) inhibitors. An update

The angiotensin converting enzyme (ACE) inhibitors are a group of effective drugs with a unique mechanism of action. These drugs have proven to be useful for hypertension and congestive heart failure. Early clinical trials of captopril used doses that are now known to be inappropriately high, and dose-related adverse effects were observed frequently. The recognition that lower doses are effective has reduced the incidence of adverse reactions and resulted in improved patient tolerance. When patients are properly selected and correctable risk factors are removed, serious side effects are uncommon. Unfortunately, the early reputation of nephrotoxicity persists, as does the belief that significant blood dyscrasias, endocrine effects and rash are serious risks for the average patient. After wide use of captopril, enalapril and lisinopril, and investigational trials of nearly a dozen newer agents, a sufficiency of clinical observation, experimental evidence and accurate postmarketing recording of events is accumulating to allow insight into the major toxicities with regard to more intelligent patient selection, more rational dosing and proper identification of risk factors. The most common adverse reactions are cough and skin rash. It appears that the agents are generally not cross-reactive with regard to skin rash, although it is not clear whether this effect is drug-specific or class-specific with regard to cough. Statistically but not clinically significant lowering of haemoglobin and hematocrit is common; these effects are inconsequential in most patients. Neutropenia, once thought to be prevalent, now appears to be so only in patients with autoimmune or collagen-vascular disease; the majority of patients outside these groups are at low risk. Hyperkalaemia is a frequent occurrence. This should not be surprising in view of the effect of the ACE inhibitors on plasma aldosterone. When dietary potassium intake is regulated and sources of altered potassium excretion are identified, hyperkalaemia is seldom a serious problem. Identification of sodium and water deficits allows correction before the drugs are started, and the frequency of hypotension and hyperkalaemia caused by the drugs is quite low if these factors are properly managed. An unexpected finding emerging in recent years is the dry cough associated with ACE inhibitor therapy. Its mechanism is not definitely known. Nonsteroidal anti-inflammatory drugs may control this symptom in some patients. The frequent observation of proteinuria in patients taking ACE inhibitors has gained notice and sometimes caused undue alarm. It is difficult to separate disease effects in diabetes and hypertension from true drug effects.(ABSTRACT TRUNCATED AT 400 WORDS)

Captopril and hydrochlorthiazide--a safe antihypertensive for use in general practice?

The combination of captopril and hydrochlorthiazide was assessed in 15 hypertensive patients in a general practice setting. The first aim was to determine whether the fall in blood pressure, noted after the first dose of an ACE inhibitor given alone, became unacceptable when the drug was given with a diuretic. The second aim was to assess the impact of the ACE inhibitor on the biochemical abnormalities associated with thiazide diuretic therapy. The drug combination markedly reduced blood pressure but not below 110 systolic after the first dose. In the long-term the treatment significantly lowered blood pressure but did not produce any significant or clinically relevant changes in serum chemistry.

The response to the first dose of an angiotensin converting enzyme inhibitor in uncomplicated hypertension--a placebo controlled study utilising ambulatory blood pressure recording

1. The importance of total dose to the initial hypotensive response with an angiotensin converting enzyme inhibitor (quinapril) was assessed using a suggested 'maintenance' dose (20 mg) or matched placebo in a randomised double-blind study in patients with uncomplicated hypertension. 2. Thirty-two patients were recruited who were not on therapy or had not received diuretic therapy in their existing drug treatment in the preceding 4 weeks. Secondary causes of hypertension had previously been excluded and sustained clinic blood pressures of SBP greater than 160 mmHg and/or DBP greater than 90 mmHg were taken as indications for a trial of adjuvant or monotherapy with an ACE inhibitor. 3. After uneventful supervised therapy with quinapril in an open pilot study (n = 5) 27 patients entered a double-blind, randomised, crossover study of quinapril or placebo using ambulatory monitoring to assess BP response. 4. All patients remained asymptomatic and both therapy and monitoring were well tolerated. A smooth onset of antihypertensive effect was noted with an overall 24 h placebo corrected fall in systolic BP of 9.9 mmHg (7.2-12.6 95% CI) and diastolic BP of 6.4 mmHg (4.2-8.8) with no significant effect on heart rate. Individual placebo corrected maximal responses during the first 8 h following quinapril showed a wide range for both systolic (+1.56 to 44.0 mmHg) and diastolic (+2.3 to -35.6 mmHg) pressure. Larger falls tended to be associated with higher baseline pretreatment pressures but in no case did absolute systolic pressure fall below 100 mmHg during the first 8 h following administration of placebo or quinapril.(ABSTRACT TRUNCATED AT 250 WORDS)

Safety profile of benazepril in essential hypertension

Data from clinical trials with benazepril suggest that the safety profile of benazepril is similar to that of other angiotensin-converting enzyme (ACE) inhibitors. Treatment-related side effects occurred in 20% of benazepril-treated patients and in 18% of patients receiving placebo. The most commonly reported side effects with benazepril were headache, dizziness, and fatigue. The incidence of side effects was not affected by the degree of hypertension, age, gender, race, dosage, or the degree of renal impairment. Side effects believed to be related to the pharmacologic action of ACE inhibitors as a class include symptomatic hypotension, which occurred at a relatively low rate with benazepril, and hyperkalemia and elevation of serum creatinine, which occurred to the same extent with benazepril as has been noted with other ACE inhibitors. The mechanism of cough as an ACE inhibitor side effect is unknown; the incidence was similar to that with other ACE inhibitors. Rash and taste disturbance have occurred rarely with benazepril. The incidence of neutropenia and of proteinuria was the same in both the benazepril and placebo groups. Renal failure in hypertensive patients treated with benazepril has not been reported. Overall, benazepril is generally well tolerated by hypertensive patients. The incidence of most side effects is comparable to that with other ACE inhibitors and placebo.

Perindopril. A review of its pharmacological properties and therapeutic use in cardiovascular disorders

Perindopril is a long acting angiotensin converting enzyme (ACE) inhibitor, which displays similar pharmacodynamic properties to other agents in this class. In common with enalapril, it is also a prodrug. After absorption, perindopril is hydrolysed to the active metabolite, perindoprilat, and with once daily administration adequate 24-hour inhibition of ACE is obtained. Perindopril 4 to 8mg once daily is usually effective for blood pressure control in patients with mild to moderate essential hypertension. Those patients who do not respond adequately to monotherapy with perindopril usually respond with the addition of a second agent, such as a thiazide diuretic. General practice trials indicate that perindopril is at least as effective and as well tolerated as usual therapeutic dosages of captopril, atenolol or hydrochlorothiazide plus amiloride in mild to moderate essential hypertension. Preliminary results indicate that perindopril may also be effective in patients with severe hypertension or congestive heart failure. Perindopril is generally well tolerated and has an adverse effect profile similar to that of other ACE inhibitors. It further clinical experience confirms initial findings, perindopril is likely to represent a useful alternative to other members of the ACE inhibitor class in all grades of hypertension and congestive heart failure.

Nonpeptide angiotensin II receptor antagonists

Substantial progress has been made recently in the development of nonpeptide angiotensin II receptor antagonists, a goal that has long remained an unmet challenge. Pieter Timmermans and colleagues review the pharmacology and the course of events that led to the identification of the lead compound and clinical candidate DuP753. Nonpeptide angiotensin II receptor antagonists represent novel therapeutic agents and are the preferred probes for exploring the (patho)physiological role(s) of angiotensin II. In addition, these compounds have provided evidence for the existence of different binding sites/receptors for angiotensin II.

Uneventful self poisoning with a very high dose of captopril

A 43-year-old patient with mild heart failure attempted suicide by ingesting between 5000 and 7500 mg of captopril. Blood pressure oscillated around 100-120/50-75 mmHg and pulse rate showed no tendency to accelerate (75-100/min). The psychiatric examination showed no drug induced psychopathological symptoms. The calculated half-life of captopril was 4.4 h. Seven hours after ingestion of approximately 50 times the maximal therapeutic daily dose of captopril the serum concentration reached 20 micrograms/ml. The calculated amount of absorbed captopril was approximately 5400 mg. Atrial natriuretic factor (ANF) plasma levels were slightly elevated and showed no tendency to increase or to fall.

Once-daily lisinopril compared with twice-daily captopril in the treatment of mild to moderate hypertension: assessment of office and ambulatory blood pressures

This multicenter, double-blind, parallel-group study compared the antihypertensive effects of two angiotensin-converting enzyme inhibitors, lisinopril and captopril, in 70 patients (35 lisinopril, 35 captopril) with mild-to-moderate essential hypertension. Doses of 10, 20, and 40 mg once-daily lisinopril or 25, 50, and 100 mg bid captopril were increased at biweekly intervals until patients responded to treatment, as defined by a decrease in office diastolic pressure to less than 90 mm Hg or at least a 10 mm Hg decrease from baseline. Patients who responded to a 2-week titration dose remained at that dose for another 2 weeks. Blood pressure assessments were made using both office and ambulatory blood pressure monitoring. Area under the curve analysis of ambulatory blood pressure reductions showed significant differences between treatment groups for both systolic (P = .023) and diastolic (P = .007) blood pressures, with lisinopril-treated patients showing the most significant reduction in pressure. Greater reductions (P less than .05) were also noted in patients receiving lisinopril at hours 10 to 12, suggesting two blood pressure troughs for those receiving captopril. Both drugs were well tolerated, and no patients withdrew from either treatment group. The authors concluded that after at least 4 weeks of therapy, once-daily lisinopril administration was more effective than twice-daily captopril administration in reducing blood pressure, when measured by 24-hour ambulatory blood pressure monitoring.

Anaphylactoid reactions during hemodialysis on AN69 membranes in patients receiving ACE inhibitors

We report five life-threatening anaphylactoid reactions occurring within the very first minutes of hemodialysis on polyacrylonitrile (AN69) capillary dialyzers in three patients receiving ACE inhibitors. Such reactions were not observed either in patients treated with ACE inhibitors but dialyzed on other membranes (N = 9), nor in patients on AN69 who did not receive ACE inhibitors (N = 19). These anaphylactoid reactions could be due to bradykinin accumulation, as a result of both increased synthesis--by interaction of blood with the AN69 polymer--and catabolism blockade by ACE inhibitors.

Guidelines for treating hypertension in the elderly

The incidence of hypertension increases with ageing, and one-third of the elderly population is affected. The role of hypertension as a cardiovascular risk factor has been confirmed in the elderly by the incidence of stroke and myocardial infarction. Effective treatment of hypertension significantly reduces the risk of associated complications: cardiovascular death, congestive heart failure and stroke. There are numerous secondary effects of antihypertensive treatment and the prescription and monitoring of treatment should take into account potential effects specific to elderly patients.

Angiotensin-converting enzyme inhibitors and their influence on inflammation, bronchial reactivity and cough. A research review

Synthetic orally active angiotensin-converting enzyme (ACE) inhibitors have been successfully used in the treatment of congestive heart failure and hypertension, particularly in hypertensive subjects with increased renin-angiotensin-aldosterone-system activity. Adverse skin reactions, angioneurotic oedema and rapidly decreasing lung function in asthmatics have been reported following medication with ACE inhibitors. Furthermore, these drugs have been associated with a persistent dry cough in subjects without previous known bronchial hyper-reactivity. There is reason to believe that an ACE inhibitor-induced cough is due to an increased inflammatory state in the airways of susceptible individuals, and that this cough might thereby have pathophysiological features in common with the cough seen as an early symptom of asthma. All inflammatory responses, wheal and flare reactions, infiltration of neutrophils, eosinophils, basophils and monocytes were enhanced by ACE inhibitors. A dose-response relationship for the proinflammatory effect of the ACE inhibitor has been demonstrated.

Tolerability of enalapril in congestive heart failure

This report reviews the tolerability profile of enalapril, an angiotensin-converting enzyme (ACE) inhibitor, in the treatment of patients with congestive heart failure. Data have been collected from 546 patients treated with enalapril for up to 9 months in clinical trials other than the Cooperative North Scandinavian Enalapril Survival Study. Results in patients treated with enalapril (n = 193) or placebo (n = 195) in double-blind, controlled clinical trials show that the incidences of death, serious adverse experiences, and adverse experiences requiring discontinuation of double-blind therapy, as well as the overall incidence of such experiences, were similar in the 2 groups. However, certain adverse experiences that are related to the mechanism of action of ACE inhibitors were seen more often after enalapril than after placebo treatment. Dizziness and hypotension were the most frequent adverse experiences reported in patients with heart failure treated with enalapril. The most frequent laboratory adverse experiences were increases in blood urea nitrogen and serum creatinine levels. hyperkalemia was also seen in patients receiving enalapril. It is possible to identify patients at risk of these experiences before initiating treatment with enalapril and to take certain measures (such as withholding or reducing the dose of diuretic drugs and discontinuing potassium supplements or potassium-sparing diuretic drugs) to reduce the likelihood that hypotension, increases in blood urea nitrogen and serum creatinine levels, or hyperkalemia will occur. Angioedema, a recognized adverse effect of ACE inhibitors, was not seen in the clinical trials reviewed here. Cough , another recognized adverse effect of these agents, was seen infrequently and rarely resulted in the discontinuation of enalapril.(ABSTRACT TRUNCATED AT 250 WORDS)

ACE inhibitors and diuretics. The benefits of combined therapy for hypertension

Hypertension and its consequences continue to threaten the health of as many as 60 million Americans. Effective control of blood pressure can be achieved in some patients with a single agent and in many of the remainder with combination therapy. The ideal combination regimen is one that is at least as effective as a single agent, has minimal or no side effects, has a wide therapeutic index, is simple to administer, and is effective in a wide variety of patient populations. When used in combination, the thiazide diuretics and the angiotensin-converting enzyme inhibitors have been shown to improve blood pressure reduction over either drug used alone. In addition, the combination is effective in a wide range of patient populations (blacks and whites, young and old) and is accompanied by fewer adverse metabolic effects than the thiazides alone. Finally, the combination has a more positive impact on quality of life than other combinations involving the thiazide diuretics.

Bullous pemphigoid associated with captopril

Captopril is commonly prescribed to patients with hypertension and congestive heart failure. Adverse dermatological reactions have been reported in about ten percent of patients receiving captopril. This case report describes a 77-year-old white woman who developed bullous pemphigoid associated with the use of captopril. The patient presented with bullous eruptions localized on the palms of both hands about 50 days after captopril 25 mg bid was started. Biopsy report was consistent with bullous pemphigoid. Captopril therapy was discontinued and the lesions healed after oral corticosteroid therapy was initiated.

Postmarketing surveillance of enalapril. I: Results of prescription-event monitoring

To identify and measure the incidence of adverse effects of the angiotensin converting enzyme inhibitor enalapril 13,713 patients were studied for one year by prescription-event monitoring. Precise information about the duration of treatment was available for 12,543 patients. The frequency of many events was calculated, including dizziness (483 patients; 3.9%), persistent dry cough (360; 2.9%), headache (310; 2.5%) hypotension (218; 1.7%), and syncope (155; 1.2%). Less common reactions included angioedema, urticaria, and muscle cramps. Altogether 1098 (8%) patients died and the notes of 913 of them (83%) were obtained for detailed scrutiny. With the exception of a few patients with renal failure who deteriorated during treatment (reported on separately), no death was attributed to enalapril. Enalapril was considered to be effective, even in patients with advanced cardiac failure. These results for enalapril are reassuring and provide further evidence of the value of prescription-event monitoring.

Lisinopril. A preliminary review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in hypertension and congestive heart failure

Lisinopril is an orally active angiotensin-converting enzyme (ACE) inhibitor which at dosages of 20 to 80 mg once daily is effective in lowering blood pressure in all grades of essential hypertension. It is at least as effective as usual therapeutic dosages of hydrochlorothiazide, atenolol, metoprolol and nifedipine while direct comparisons with other ACE inhibitors have not been reported. Many patients achieve an adequate blood pressure reduction with lisinopril alone, and in those who do not, most will with the addition of hydrochlorothiazide; lisinopril also attenuates hypokalaemia induced by thiazide diuretics. In patients with congestive heart failure resistant to conventional therapy, lisinopril 2.5 to 20 mg once daily improved indices of cardiac function and appeared to produce greater benefit than captopril in one controlled study. Lisinopril is well tolerated, with few serious adverse effects being reported. Thus, lisinopril is a suitable treatment for essential hypertension and shows promise in the treatment of congestive heart failure. If additional studies confirm these preliminary findings, then lisinopril will have a similar profile of indications to other ACE inhibitors, and like some other drugs in this class it offers the convenience of once daily administration.

Eye pain with nifedipine and disturbance of taste with captopril: a mutually controlled study showing a method of postmarketing surveillance

Several notifications of eye pain and blurred vision associated with treatment with nifedipine were received by New Zealand's Intensive Medicines Monitoring Programme. A questionnaire survey of patients taking nifedipine was undertaken to test the importance of these associations, with disturbance of taste associated with captopril taken as a methodological control. Altogether 961 patients taking nifedipine and 368 taking captopril were sent a questionnaire that asked whether any eye problems and changes in the sense of taste had occurred while they were taking the drug and whether these had resolved after treatment was stopped. Compliance was high: of 922 and 343 questionnaires that were assumed to have been delivered to patients taking nifedipine and captopril, respectively, 770 (84%) and 295 (86%) were returned satisfactorily completed. The distribution of sex was comparable in the two groups; patients taking captopril were slightly younger. Eye symptoms were reported in both groups, but eye pain was significantly more common in patients taking nifedipine (107 (14%) compared with 26 (9%) patients taking captopril). This is a new finding and may be related to ocular vasodilatation. Theoretically, glaucoma is a possible adverse reaction. Loss of taste was significantly associated with captopril, but no other disturbances of taste showed significant associations. Loss of taste persisted in 27 out of 35 patients who continued to take captopril and in three out of eight patients when the drug was withdrawn. This study showed a method of assessing early signs of adverse drug reactions, which has been used once before and identified previously unrecognised reactions.

Cough associated with captopril and enalapril

Thirty three reports of cough associated with captopril and 26 associated with enalapril received by the New Zealand intensive medicines monitoring programme were reviewed. The programme is a specialised part of the New Zealand postmarketing surveillance system. Review of these reports showed that the cough was an adverse reaction to the drugs, occurred even with low dose treatment, and was severe enough to warrant withdrawal of the drugs in most of the cases reported. A significant sex difference was shown, with women predominating. The reaction seemed to be a greater problem with enalapril, and in seven patients it occurred with both captopril and enalapril. Withdrawal of treatment resulted in rapid recovery, and no long term effects were shown. The pathogenesis of the reaction is unknown, but possible mediators include bradykinin and prostaglandins.