Drug-induced hypoglycemia. A review based on 473 cases

Drug-Induced Hypoglycemia in Neonates Born to Nondiabetic Women Treated with Medications during the Pregnancy or the Labor: A Systematic Review of the Literature

The prompt identification of at-risk newborns for drug-induced hypoglycemia can minimize the risk for adverse side effects, inappropriate investigations, and considerable unnecessary costs. Existing literature discusses drug-induced hypoglycemia, but a systematic description of neonatal hypoglycemia induced or exacerbated by maternal medications is missing. We reviewed the association between neonatal hypoglycemia and maternal medications. We systematically searched the literature according to the PICOS model on drug-induced hypoglycemia in neonates born to nondiabetic women treated with medications during the pregnancy or the labor. The main outcomes of the review were: (1) prevalence of hypoglycemia, (2) risk factors and potential confounders, (3) time at onset and severity of hypoglycemia, (4) dose-response gradient, (5) metabolic features of hypoglycemia, (6) modalities to treat hypoglycemia, and (7) quality of the studies. We included 69 studies in this review and we identified 11 groups of maternal drugs related to neonatal hypoglycemia. Results were classified for each outcome. Our review aims at supporting clinicians in the identification of the newborn at risk for hypoglycemia and in the differential diagnosis of neonatal hypoglycemia. Further studies are necessary to assess the risk of neonatal hypoglycemia associated with common maternal medications. KEY POINTS: · A systematic description of neonatal hypoglycemia induced or exacerbated by maternal medications is missing.. · In our review we identified 11 groups of maternal drugs related to neonatal hypoglycemia.. · Our review aims at supporting clinicians in the identification of the newborn at risk for hypoglycemia..

Rebirth of the Incretin Concept: Its conception and early development

This paper describes the resurrection of the Incretin Concept in the early 1960s. It began with the more or less simultaneous discovery by three groups working independently in London. Dupre demonstrated that secretin given intravenously with glucose increased its rate of disappearance from the blood, McIntyre and co-workers established that hyperglycaemia evoked by oral glucose stimulated more insulin secretion than comparable hyperglycaemia produced by intravenous glucose and Marks and Samols established the insulinotropic properties of glucagon. The concept evolved with the discovery by Samols and co-workers that oral glucose stimulated the release of immunoreactive glucagon-like substances from the gut mucosa and the subsequent isolation of glucagon immunoreactive compounds, most notably oxyntomodulin and glicentin, and of gastic inhibitory polypetide (GIP). It concluded with the isolation and characterisation of glucagon-like peptide 1 (7-36) amide.

Analysis of Risk Factors for Hypoglycemic Coma in 194 Patients with Type 2 Diabetes

Background

The present study was conducted to analyze possible risk factors in patients with type 2 diabetes who are in hypoglycemic coma.

Material/Methods

A total of 194 patients with type 2 diabetic hypoglycemic coma who were admitted to our hospital between January 2010 and January 2016 were included. The patients were all in coma on admission, and their blood glucose levels were lower than 2.8 mmol/L. None of the patients had type I diabetes, specific types of diabetes, or gestational diabetes. Multiple linear regression analysis was used to determine possible factors associated with hypoglycemic coma.

Results

Among the patients, 82 were male and 112 were female (mean age, 66.88±10.62 years). In addition, 72 patients lived in urban areas and 122 lived in rural areas. Occurrence of hypoglycemic coma was correlated with difference between urban and rural residence, glycosylated hemoglobin (HbA1c) level, combined hypertension, and combined neural complications. Self-purchased drugs resulted in significantly lower blood glucose level at the onset of hypoglycemic coma than insulin, secretagogue, or non-secretagogue drugs. Blood glucose level at onset was correlated with season. Patients living in rural areas or with combined macrovascular or microvascular complications had prolonged hospital stay and poor prognosis.

Conclusions

Our results demonstrate that rural residence, higher HbA1c level, combined hypertension, and combined neural complications increase the incidence of hypoglycemic coma. Use of self-purchased drugs and colder seasons may result in lower blood glucose levels in patients with hypoglycemic coma.

The risks of nocturnal hypoglycaemia in insulin-treated diabetes

Over half of all episodes of severe hypoglycaemia (requiring external help) occur during sleep, but nocturnal hypoglycaemia is often asymptomatic and unrecognised. The precise incidence of nocturnal hypoglycaemia is difficult to determine with no agreed definition, but continuous glucose monitoring has shown that it occurs frequently in people taking insulin. Attenuation of the counter-regulatory responses to hypoglycaemia during sleep may explain why some episodes are undetected and more prolonged, and modifies cardiovascular responses. The morbidity and mortality associated with nocturnal hypoglycaemia is probably much greater than realised, causing seizures, coma and cardiovascular events and affecting quality of life, mood and work performance the following day. It may induce impaired awareness of hypoglycaemia. Cardiac arrhythmias that occur during nocturnal hypoglycaemia include bradycardia and ectopics that may provoke dangerous arrhythmias. Treatment strategies are discussed that may help to minimise the frequency of nocturnal hypoglycaemia.

MANAGEMENT OF ENDOCRINE DISEASE: Pathogenesis and management of hypoglycemia

Glucose is the main substrate utilized by the brain and as such multiple regulatory mechanisms exist to maintain glucose concentrations. When these mechanisms fail or are defective, hypoglycemia ensues. Due to these robust mechanisms, hypoglycemia is uncommon and usually occurs in the setting of the treatment of diabetes using glucose-lowering agents such as sulfonylureas or insulin. The symptoms of hypoglycemia are non-specific and as such it is important to confirm hypoglycemia by establishing the presence of Whipple's triad before embarking on an evaluation for hypoglycemia. When possible, evaluation of hypoglycemia should be carried out at the time of spontaneous occurrence of symptoms. If this is not possible then one would want to create the circumstances under which symptoms occur. In cases where symptoms occur in the post absorptive state, a 72-h fast should be performed. Likewise, if symptoms occur after a meal then a mixed meal study may be the test of choice. The causes of endogenous hyperinsulinemic hypoglycemia include insulinoma, post-bariatric hypoglycemia and noninsulinoma pancreatogenous hypoglycemia syndrome. Autoimmune hypoglycemia syndrome is clinically and biochemically similar to insulinoma but associated with high levels of insulin antibodies and plasma insulin. Other important causes of hypoglycemia include medications, non-islet cell tumors, hormonal deficiencies, critical illness and factitious hypoglycemia. We provide an overview of the pathogenesis and management of hypoglycemia in these situations.

Causative anti-diabetic drugs and the underlying clinical factors for hypoglycemia in patients with diabetes

Recent clinical trials indicated that the intensive glycemic control do not reduce cardiovascular disease mortality among diabetic patients, challenging a significance of the strict glycemic control in diabetes management. Furthermore, retrospective analysis of the Action to Control Cardiovascular Risk in Diabetes study demonstrated a significant association between hypoglycemia and mortality. Here, we systematically reviewed the drug-induced hypoglycemia, and also the underlying clinical factors for hypoglycemia in patients with diabetes. The sulfonylurea use is significantly associated with severe hypoglycemia in patients with type 2 diabetes. The use of biguanide (approximately 45%-76%) and thiazolidinediones (approximately 15%-34%) are also highly associated with the development of severe hypoglycemia. In patients treated with insulin, the intensified insulin therapy is more frequently associated with severe hypoglycemia than the conventional insulin therapy and continuous subcutaneous insulin infusion. Among the underlying clinical factors for development of severe hypoglycemia, low socioeconomic status, aging, longer duration of diabetes, high HbA1c and low body mass index, comorbidities are precipitating factors for severe hypoglycemia. Poor cognitive and mental functions are also associated with severe hypoglycemia.

Drug-induced hypoglycaemia: an update

Drugs are the most frequent cause of hypoglycaemia in adults. Although hypoglycaemia is a well known adverse effect of antidiabetic agents, it may occasionally develop in the course of treatment with drugs used in everyday clinical practice, including NSAIDs, analgesics, antibacterials, antimalarials, antiarrhythmics, antidepressants and other miscellaneous agents. They induce hypoglycaemia by stimulating insulin release, reducing insulin clearance or interfering with glucose metabolism. Several drugs may also potentiate the hypoglycaemic effect of antidiabetic agents. Administration of these agents to individuals with diabetes mellitus is of most concern. Many of these drugs, and depending on clinical setting, may also induce hyperglycaemia. Drug-induced hepatotoxicity and nephrotoxicity may lead in certain circumstances to hypoglycaemia. Some drugs may also induce hypoglycaemia by causing pancreatitis. Drug-induced hypoglycaemia is usually mild but may be severe. Effective clinical management can be handled through awareness of this drug-induced adverse effect on blood glucose levels. Herein, we review pertinent clinical information on the incidence of drug-induced hypoglycaemia and discuss the underlying pathophysiological mechanisms, and prevention and management.

Uncoventional views on certain aspects of toxin-induced metabolic acidosis

This discussion will highlight the following 9 specific points that related to metabolic acidosis caused by various toxins. The current recommendation suggests that alcohol dehydrogenase inhibitor fomepizole is preferred to ethanol in treatment of methanol and ethylene glycol poisoning, but analysis of the enzyme kinetics indicates that ethanol is a better alternative. In the presence of a modest increase in serum osmolal gap (<30 mOsm/L), the starting dose of ethanol should be far less than the usual recommended dose. One can take advantage of the high vapor pressure of methanol in the treatment of methanol poisoning when hemodialysis is not readily available. Profuse sweating with increased water ingestion can be highly effective in reducing methanol levels. Impaired production of ammonia by the proximal tubule of the kidney plays a major role in the development of metabolic acidosis in pyroglutamic acidosis. Glycine, not oxalate, is the main final end product of ethylene glycol metabolism. Metabolism of ethylene glycol to oxalate, albeit important clinically, represents less than 1% of ethylene glycol disposal. Urine osmolal gap would be useful in the diagnosis of ethylene glycol poisoning, but not in methanol poisoning. Hemodialysis is important in the treatment of methanol poisoning and ethylene glycol poisoning with renal impairment, with or without fomepizole or ethanol treatment. Severe leucocytosis is a highly sensitive indicator of ethylene glycol poisoning. Uncoupling of oxidative phosphorylation by salicylate can explain most of the manifestations of salicylate poisoning.

Severe hypoglycaemia and cognitive impairment in older patients with diabetes: the Fremantle Diabetes Study

AIMS/HYPOTHESIS

The aim was to investigate the relationship between severe hypoglycaemia and cognitive impairment in older patients with diabetes.

METHODS

A sample of 302 diabetic patients aged >/=70 years was assessed for dementia or cognitive impairment without dementia in 2001-2002 and a subsample of non-demented patients (n = 205) was followed to assess cognitive decline. A history of severe hypoglycaemia was determined from self-reports, physician assessments and records of health service use for hypoglycaemia (HSH). Prospective HSH was determined up to 2006. Data analysis, including multiple logistic and Cox regression models, was used to determine whether: (1) there were cross-sectional associations between hypoglycaemia and cognitive status, (2) historical hypoglycaemia predicted cognitive decline, and (3) baseline cognitive status predicted subsequent HSH.

RESULTS

There were significant cross-sectional associations between both cognitive impairment and dementia and hypoglycaemia. Independent risk factors for future HSH included dementia (hazard ratio 3.00, 95% CI 1.06-8.48) and inability to self-manage medications (hazard ratio 4.17, 95% CI 1.43-12.13). However, there were no significant associations between historical hypoglycaemia, incident HSH and cognitive decline.

CONCLUSIONS/INTERPRETATION

Dementia is an important risk factor for hypoglycaemia requiring health service utilisation. We found no evidence that hypoglycaemia contributes to cognitive impairment in older patients with diabetes.

Hypoglycaemia in elderly diabetic patients

Occurring in the elderly diabetic patients, hypoglycaemia may have serious consequences in terms of morbidity and mortality, but this severe prognosis is nowadays less frequently observed. The clinical manifestations may be somewhat different from those observed in young subjects: symptoms are less frequent, generally neurologic manifestations. The rate of severe hypoglycaemia remains low (about 1.4 episode per 100 patient-years), but increases rapidly in the very elderly and also with insulin therapy, co-morbid conditions especially renal insufficiency, and associated treatments, as well as with unawareness of symptoms. Prevention requires reinforced education for the patient and caregiver, particularly concerning diet, knowledge of signs of hypoglycaemia, and appropriate treatment. Self-monitoring of blood glucose, by the patient when possible, or by a familial or medical caregiver, should be encouraged in order to detect asymptomatic episodes of hypoglycaemia and better adapt antidiabetic treatment.

Quinolizidine alkaloids isolated from Lupinus species enhance insulin secretion

We have analyzed the effect of quinolizidine alkaloids from Lupinus species upon insulin secretion. Isolated normal rat islets were incubated with 3.3, 8.3, and 16.7 mM glucose, in the presence or absence of different concentrations of lupanine (0.05, 0.5, and 1.0 mM), 13-alpha-OH lupanine, 17-oxo-lupanine, and 2-thionosparteine. Insulin release was measured by radioimmunoassay. While 2-thionosparteine enhanced insulin secretion at all glucose concentrations, lupanine did at 8.3 and 16.7 mM, and 13-alpha-OH lupanine or 17-oxo-lupanine only at 16.7 mM glucose. Diazoxide (0.1 mM) decreased the effect of all alkaloids, without suppressing it completely. Consequently, blockage of beta-cell K(ATP)-sensitive channels is at least one of the mechanisms involved in the enhancing secretagogue effects of quinolizidine alkaloids. The fact that 13-alpha-OH lupanine and 17-oxo-lupanine only exert their secretagogue effect at high glucose concentrations could be of additional value when considering their potential use in the treatment of type 2 diabetes.

Hospital hypoglycemia: not only treatment but also prevention

OBJECTIVE

To propose a strategy, applicable on general hospital wards, for prevention of hypoglycemia in hospitalized patients.

RESULTS

Although the mortality rate among hospitalized patients with hypoglycemia has been shown to be 22.2 to 27% in series that included patients with diabetes, some investigators have shown that hypoglycemia is not an independent predictor of mortality. Outside the critical care setting, the comparative risks of hyperglycemia and hypoglycemia and the relationship of hospital hypoglycemia to intensification of glycemic control have not been determined. The reported incidence of hospital hypoglycemia ranges from 1.2% for hospitalized adults to 20% for nonpregnant patients with diabetes admitted without a metabolic emergency. Among patients receiving antihyperglycemic therapy, the literature describes precipitating events--usually a sudden change of caloric exposure-- and predisposing conditions for hypoglycemic episodes.

CONCLUSION

Hospital hypoglycemia is predictable, and it is preventable by measures other than undertreatment of hyperglycemia. Physician orders for antihyperglycemic therapy should be written and, if necessary, be revised so as to respond to the presence of predisposing conditions for hypoglycemia. A ward-based protocol or hospital-wide policy should establish the appropriate response to triggering events. Within the time frame of action of previously administered antihyperglycemic drugs (after abrupt interruption of caloric exposure), the threshold for preventive intravenous administration of dextrose is a glucose concentration of 120 mg/dL.

The advantages and disadvantages of a 'herbal' medicine in a patient with diabetes mellitus: a case report

BACKGROUND

Patient-initiated alternative treatments in the management of chronic conditions are common and increasing in the United Kingdom. To date, there have been no reports of herbal medicine use alone in the management of diabetes mellitus. We report here the case of a man who attained excellent glycaemic control using a 'herbal' medicine and reveal how important it was to identify the products of active constituents.

CASE REPORT

A 48-year-old man attending our clinic in Tooting, South London with known Type 2 diabetes, with evidence of both micro- and macro-vascular diabetes-related complications, was poorly controlled despite a drug regimen consisting of oral metformin and twice daily insulin. He went to India for at least 1 year and on returning to the clinic had excellent glycaemic control off all diabetic medication. While away he had started himself on a regimen of three different 'herbal' balls. Samples of blood were found to contain chlorpropamide in a therapeutic concentration; chlorpropamide was also found in one of the balls. He has been counselled on the potential risks associated with chlorpropamide and his treatment reverted to a more conventional treatment regimen.

CONCLUSIONS

General practitioners and hospital physicians should be alert to those patients returning from abroad on effective 'herbal' medications that these may in fact contain an active ingredient.

Clinical review of glimepiride

This article reviews the pharmacological and clinical aspects of glimepiride, the latest second-generation sulfonylurea for treatment of Type 2 diabetes mellitus (DM). Glimepiride therapy ameliorates the relative insulin secretory deficit found in most patients with Type 2 DM. It is a direct insulin secretagogue; indirectly, it also increases insulin secretion in response to fuels such as glucose. Its action to augment insulin secretion requires binding to a high affinity sulfonylurea receptor, which results in closure of ATP-sensitive potassium channels in the beta-cells of the pancreas. The question has been raised whether insulin secretagogues by acting on vascular or myocardial potassium channels may prevent ischaemic preconditioning, a physiological adaptation that could affect the outcome of coronary heart disease, but there is evidence against this concern being applicable to glimepiride. Glimepiride's antihyperglycaemic efficacy is equal to other secretagogues. It has pharmacokinetic properties that make it less prone to cause hypoglycaemia in renal dysfunction than some other insulin secretagogues, particularly glyburide (also known as glibenclamide in Europe). Its convenient once daily dosing may enhance compliance for diabetic patients who often also require medications for other co-morbid conditions, such as hypertension, hyperlipidaemia and cardiac disease. Glimepiride is approved for monotherapy, for combination with metformin and with insulin. Clinically, its reduced risk of hypoglycaemia makes it preferable to some other insulin secretagogues when attempting to achieve recommended glycaemic control (haemoglobin A(1c) (HgbA(1c)) 7%). Using suppertime neutral protamine Hagedorn (NPH) and regular insulin with morning glimepiride in overweight diabetic patients achieves glycaemic goals more quickly than insulin alone and with lower insulin doses.

Comparative tolerability of sulphonylureas in diabetes mellitus

The sulphonylurea drugs have been the mainstay of oral treatment for patients with diabetes mellitus since they were introduced. In general, they are well tolerated, with a low incidence of adverse effects, although there are some differences between the drugs in the incidence of hypoglycaemia. Over the years, the drugs causing the most problems with hypoglycaemia have been chlorpropamide and glibenclamide (glyburide), although this is a potential problem with all sulphonylureas because of their action on the pancreatic beta cell, stimulating insulin release. Other specific problems have been reported with chlorpropamide that occur only rarely, if at all, with other sulphonylureas. Hyponatraemia secondary to inappropriate antidiuretic hormone activity, and increased flushing following the ingestion of alcohol, have been well described. The progressive beta cell failure with time results in eventual loss of efficacy, as these agents depend on a functioning beta cell and are ineffective in the absence of insulin-producing capacity. Differences in this secondary failure rate have been reported, with chlorpropamide and gliclazide having lower failure rates than glibenclamide or glipizide. The reasons for this are unclear, but the more abnormal pattern of insulin release produced by glibenclamide may be partly responsible and, indeed, may explain the increased risk of hypoglycaemia with this agent. Previously reported increased mortality associated with tolbutamide therapy has not been substantiated, and more recent data have shown no increased mortality from sulphonylurea treatment. Indeed, benefit from glycaemic control, regardless of the agent used--insulin or sulphonylurea--was reported by the United Kingdom Prospective Diabetes Study. Nevertheless, there is still ongoing controversy in view of the experimental evidence, mainly from animal studies, of potential adverse effects on the heart from sulphonylureas, but these are difficult to extrapolate into clinical situations. Most of these studies have been carried out with glibenclamide, which makes comparison of possible risk difficult. Other cardiovascular risk factors may be modified by gliclazide, which seems unique among the sulphonylureas in this respect. Its reported haemobiological and free radical scavenging activity probably resides in the azabicyclo-octyl ring structure in the side chain. Reduced progression or improvement in retinopathy has been reported in comparative trials with other sulphonylureas, and the effect is unrelated to improvements in glycaemia. There are differences between the sulphonylureas in some adverse effects, risk of hypoglycaemia, failure rates and actions on vascular risk factors. As a group of drugs, they are very well tolerated, but differences in overall tolerability can be identified.

Drug-induced hypoglycemia

Therapeutically administered antidiabetic drugs, notably insulin and the sulfonylureas, are undoubtedly the most common cause of hypoglycemia encountered in clinical practice. Nevertheless, an impressive list of other drugs can produce hypoglycemia unpredictably in seemingly healthy individuals in whom it may masquerade as spontaneous hypoglycemia. Unless the true cause is identified when the patient is first seen, fruitless and expensive overinvestigation may ensue. The most important drugs are discussed herein and brief mention made of those for which coincidence has not been eliminated.

Hypoglycemia presenting as acute respiratory failure in an infant

Hypoglycemia, a common metabolic abnormality seen in the pediatric population, is most often easily diagnosed and rapidly treated with satisfactory outcome. If not recognized and treated in prompt fashion, however, hypoglycemia may cause irreversible central nervous system injury or expose the patient to unnecessary procedures; it rarely results in death. The classic emergency department (ED) presentation of hypoglycemia, the diabetes mellitus patient using hypoglycemic therapy, is frequently encountered and adequately managed with excellent outcome. Alternatively, the patient may present to the ED in a fashion suggestive of a situation other than hypoglycemia. For example, the patient with an altered sensorium following a traumatic event, with a focal neurologic finding, or with bradycardia--all situations in which hypoglycemia is the causative issue--may not be immediately recognized as such a metabolic problem. This report presents a case of a 9-month-old boy who presented with acute respiratory failure and mental status change; the initial ED impression was one of pneumonia with sepsis. Further evaluation uncovered the actual reason for the mental status change and respiratory insufficiency: hypoglycemia was noted on laboratory analysis; no clinical evidence of pneumonia was found after thorough ED evaluation and a prolonged hospital stay. His mental status improved and his respiratory insufficiency resolved after glucose therapy. No other explanation for the respiratory failure was found during the hospital admission. It is imperative that the emergency physician consider hypoglycemia in all patients with any degree of mental status abnormality, even when the findings seem to be explained initially by other etiologies.

Rates of hypoglycemia in users of sulfonylureas

OBJECTIVE

To identify the demographic and clinical characteristics of sulfonylurea users. To assess the risk of hypoglycemia in patients treated with sulfonylureas in clinical practice, and to characterize the risk in relation to the different drugs used.

RESEARCH DESIGN AND METHODS

A cohort of 33,243 sulfonylurea users chosen from 719 clinical practices in the United Kingdom were identified through the VAMP-Research database. Information on demographic characteristics, medical diagnoses and use of medical services was obtained through the computerized records. For a stratified sample of 500 patients, general practioners completed a structured questionnaire on the duration, treatment, and complications of diabetes mellitus, obesity, alcohol use, and smoking history. Patients with a diagnosis of hypoglycemia, as recorded in the database within a time-window of a sulfonylurea prescription, were identified. Incidence rates per person-year of sulfonylurea therapy were estimated.

RESULTS

Other than a longer duration of diabetes in users of chlorpropamide, no differences were observed among users of different sulfonylurea agents with respect to diabetic complications, adequacy of diabetic control, obesity, smoking, and excessive alcohol consumption. A diagnosis of hypoglycemia during sulfonylurea therapy was recorded in 605 people over 34,052 person-years of sulfonylurea therapy, which converted into an annual risk of 1.8%. The risk in glibenclamide users was higher than in users of other types of sulfonylureas uses. Duration of therapy, concomitant use of insulin, sulfonylurea-potentiating or antagonizing and concomitant use of beta-blockers were predictive of the risk of developing hypoglycemia.

DISCUSSION

Drug use patterns showed comparability among users of different sulfonylurea agents. Our findings suggest that the rate of diagnosis of hypoglycemia made by physicians is higher for glibenclamide than for other sulfonylureas. An epidemiological study with objectively diagnosed hypoglycemia should be undertaken to confirm these results.

Acute hypoglycemia masquerading as head trauma: a report of four cases

Hypoglycemia, a commonly encountered metabolic emergency, is most often easily diagnosed and rapidly treated with satisfactory patient outcome. If not recognized and treated promptly, hypoglycemia may cause irreversible central nervous system injury; it rarely results in death. The classic presentation of hypoglycemia, a patient with diabetes mellitus on medical therapy (Insulin or oral hypoglycemic agents) who presents with an altered sensorium, is frequently seen in the emergency department (ED). Less often, patients with this metabolic emergency present to the ED in a manner suggestive of a situation other than hypoglycemia. Patients may present with seizure activity or focal neurological deficits, leading the physician to treat a primary neurological syndrome and not immediately recognize the primary cause of the problem. Alternatively, patients with hypoglycemia will present to the ED with an altered mental status after a traumatic event. The physician may again assume that the alteration in consciousness has resulted from a head injury and not a metabolic disorder. Four cases are presented in which the medical history of the event (i.e., trauma) suggested head injury as an explanation of the presentation when, in fact, hypoglycemia was responsible for the altered sensorium. The diagnosis of hypoglycemia is easily made with the performance of a bedside screening test which can be subsequently confirmed by laboratory blood analysis. It is imperative that emergency physicians consider hypoglycemia in all patients with any mental status abnormality, focal neurological deficit, or seizure activity, even when the findings seem to be explained initially by other etiologies.

Pharmacokinetics of oral antihyperglycaemic agents in patients with renal insufficiency

This paper reviews the effects of renal insufficiency on the pharmacokinetics of oral antidiabetic drugs. Of the 3 groups of drugs currently available for the treatment of non-insulin-dependent diabetes mellitus (NIDDM), the sulphonylureas and metformin are, in general, well-tolerated and generally safe. In patients with chronic renal insufficiency, however, care must be exercised in the use of many of these drugs, as accumulation, either of the active drug or of active metabolites, can lead to serious adverse effects such as hypoglycaemia or, with metformin, lactic acidosis. The sulphonylurea drugs, to a greater or lesser degree, are metabolised in the liver to a variety of active or inactive compounds which, in general, are excreted by the kidneys. In addition, varying amounts of parent compound may depend on renal elimination. As a result, sulphonylurea drugs such as tolazamide, acetohexamide, chlorpropamide and glibenclamide (glyburide) are more likely to cause significant hypoglycaemia, as the metabolism of these drugs, compared with other commonly prescribed sulphonylureas, can lead to the accumulation of either the parent drug or the active metabolite in the presence of renal insufficiency. Tolbutamide, glipizide, gliclazide and gliquidone are much less likely to cause hypoglycaemia as their metabolites are either inactive or have minimal hypoglycaemic potency. Metformin is dependent on renal excretion and is not significantly metabolised. As a result, caution is required when treating patients with renal insufficiency where metformin accumulation can occur, with the danger of lactic acidosis. Although the correlation between creatinine clearance (CLCR) and total oral clearance of drug is weaker than the correlation between CLCR and renal clearance (CLR) of metformin, it is clear that renal insufficiency is associated with most cases of metformin-induced lactic acidosis. For this reason, clinicians in general would regard a raised plasma creatinine as a contraindication to metformin treatment. Acarbose, an alpha-glucosidase inhibitor, and a relatively new agent for treating NIDDM, is likely to be safe in patients with impaired renal function, as the drug is not significantly absorbed from the gut, but data on this subject are lacking.

Problems and pitfalls of sulphonylurea therapy in older patients

The prevalence of non-insulin-dependent diabetes mellitus (type II) increases with age, so that approximately half of all known patients in English-speaking countries are over 65 years of age. There is no reason to believe that the criteria for blood glucose control should be any less stringent for elderly patients unless they have a limited life expectancy. Sulphonylurea drugs remain an effective means of achieving blood glucose control after failure of dietary therapy alone in older patients. However, changes in normal metabolism of drugs with age and the development of other pathologies in elderly patients make it important that these drugs are prescribed with care. Severe symptomatic hypoglycaemia is the most serious adverse effect of sulphonylurea drugs and this becomes progressively more likely with increasing age, depending primarily on the substantial reduction of renal function with normal aging. Other adverse effects are much less commonly of clinical importance. To minimise the risk of hypoglycaemia, it is important that patients receive closely supervised dietary management with education about their disease for at least 3 months before sulphonylurea drugs are prescribed. In elderly patients a short-acting agent with no active metabolites should be used. As patients become older, those receiving long-acting agents can be changed to short-acting agents before problems arise. If blood glucose control appears satisfactory on treatment, then symptoms of hypoglycaemia should be sought. If control is poor, then the criteria for introduction of insulin, with appropriate education, do not differ from those in younger patients.

Alcohol-related seizures, Part I: Pathophysiology, differential diagnosis, and evaluation

Alcoholism may be society's most devastating problem short of war and malnutrition. Perhaps the most complex and perplexing medical complication of alcoholism is alcohol-related seizures. This article is a collective review designed to provide emergency physicians with an overview of the topic that is pertinent to their clinical practice. Part 1 addresses the pathophysiology, differential diagnosis, and evaluation of alcohol-related seizures. Part 2 will concentrate on the clinical presentation, management, and disposition. In addition, a classification of alcohol-related seizures will be proposed.

Frequency and symptoms of hypoglycaemia experienced by patients with type 2 diabetes treated with insulin

This study ascertained the prevalence of severe hypoglycaemia and loss of awareness of hypoglycaemia in patients with Type 2 diabetes treated with insulin. One hundred and four sequentially selected Type 2 diabetic patients were compared with 104 patients with Type 1 diabetes who were matched for duration of insulin therapy. The patients were interviewed using a standardized questionnaire. During treatment with insulin, 18 Type 2 patients had experienced fewer than two episodes of hypoglycaemia, while 86 had experienced two or more episodes; 80 (93%) reported normal awareness, six (7%) reported partial awareness, and none had absent awareness of hypoglycaemia. All 86 Type 1 diabetic patients matched to the 86 Type 2 patients had experienced multiple episodes of hypoglycaemia; 71 (83%) had normal awareness, 14 (16%) had partial awareness and one patient (1%) reported absent awareness of hypoglycaemia. The Type 1 patients who had altered awareness of hypoglycaemia had longer duration of diabetes and insulin therapy (normal awareness: 5 (1-17) years (median (range)) vs partial awareness: 9 (3-18) years, p < 0.01). Similarly, Type 2 patients with altered awareness had longer duration of diabetes (normal awareness: 11 (2-25) years vs partial awareness: 19 (8-24) years, p < 0.02) and had received insulin for longer (normal awareness: 3 (1-18) years vs partial awareness: 12 (6-17) years, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Hypoglycemic Adverse Reactions to Insulin and Sulfonylureas

The physiology and pathophysiology of hypoglycemia secondary to insulin and oral hypoglycemics are reviewed. Literature and clinical experiences, as well as litigated experiences, are discussed, and pharmacists are cautioned to exercise extreme caution when working with these agents, lest permanent brain damage or death result from their inappropriate use and monitoring.

Adverse reactions to drugs as a cause of admissions to a general teaching hospital in Hong Kong

To determine the pattern of and the risk factors for adverse drug reactions (ADRs) in Hong Kong, a prospective study of acute admissions to 2 general medical wards at the Prince of Wales Hospital was undertaken. Of the 1701 admissions included in this study, 74 (4.4%) were attributed to ADRs. Sulphonylureas, nonsteroidal anti-inflammatories (NSAIDs) and insulin accounted for 61% of cases. The most frequent ADRs were hypoglycaemia (43%) and gastrointestinal haemorrhage (29.7%). Both old age and impaired renal function appear to be important risk factors for ADRs. In such situations, careful dose adjustments, use of an alternative drug or total avoidance may be necessary. Particular attention should be given to oral hypoglycaemic drugs and NSAIDs.

Hypoglycemic activities of MTP-3631, a novel thiopyranopyrimidine derivative

MTP-3631 is a novel thiopyranopyrimidine derivative structurally different from any existent hypoglycemic agents. MTP-3631 markedly decreased basal blood glucose and improved glucose intolerance in genetically diabetic C57BL/6J ob/ob mice, which was not affected by tolbutamide. MTP-3631 also caused hypoglycemic effects in normal rats, but no change was observed in plasma insulin level. Unlike buformin, MTP-3631 did not change plasma lactate level in ob/ob mice. These results suggest that the hypoglycemic mechanism of MTP-3631 may be essentially different from those of sulfonylureas and biguanides.

Severe hypoglycaemia during treatment with glipizide

In the years 1980-87, 19 cases of severe hypoglycaemia during treatment of Type 2 diabetes with glipizide were reported to the Swedish Adverse Drug Reactions Advisory Committee. Patient age was 75 +/- 9 years (mean +/- SD) (significantly higher than in all patients on glipizide in Sweden), and the duration of glipizide treatment ranged from 1 day to 4 years. Eleven patients presented with coma, three with reduced consciousness and five with other symptoms. An uneventful early recovery occurred in 14 patients. The remaining five patients had prolonged or recurrent hypoglycaemia for up to 60 h. Two of the patients, both with complicating disorders, died. In a case-control substudy, patients with glipizide-associated hypoglycaemia were found to have renal impairment more often than age- and sex-matched controls treated with glipizide (odds ratio 4.0). The median dose of glipizide (10 mg per day) was identical to that in controls. Other drugs, notably diuretics and benzodiazepines, were more commonly used by hypoglycaemic patients (median 5 vs 2 concomitant drugs, p less than 0.001). We conclude that the use of glipizide is associated with a risk of developing severe hypoglycaemia with a clinical course that is not always benign.

Serum glucose after intraperitoneal infusion of 5% dextrose solution

STUDY OBJECTIVE

This study investigated the use of intraperitoneal (IP) glucose infusion as a therapy for hypoglycemia.

DESIGN

Randomized, placebo-controlled, crossover design, with each animal serving as its own control.

SETTING

Laboratory investigation.

TYPE OF PARTICIPANTS

Seven female New Zealand White rabbits with a mean weight of 3.7 kg.

INTERVENTIONS

Each animal was subjected to three experiments separated by a four-day period. After baseline measurements, the following interventions were undertaken: Control day, no treatment; placebo day, 10 mL/kg 0.9% normal saline solution IP; and treatment day, 10 mL/kg 5% dextrose solution IP.

MEASUREMENTS AND MAIN RESULTS

Serial serum glucose levels were obtained. Compared with control and placebo, the mean absolute serum glucose value of the treatment group was significantly higher beginning at ten minutes after intervention and continuing until conclusion of the study at 30 minutes. For these time points, the mean increase in serum glucose levels (percent change) of the treatment group compared with the control group was as follows: ten minutes, 15.5 mg/dL (0.86 mmol/L) (11%), P less than .01; 15 minutes, 20.6 mg/dL (1.14 mmol/L) (14%), P less than .01; 20 minutes, 36.5 mg/dL (2.03 mmol/L) (26%), P less than .001; and 30 minutes, 34.7 mg/dL (1.93 mmol/L) (24%), P less than .001.

CONCLUSION

Glucose instilled into the peritoneal cavity of rabbits is absorbed rapidly into the systemic circulation.

Possibility of ideal blood glucose control by a new oral hypoglycemic agent, N-[(trans-4-isopropylcyclohexyl)-carbonyl]-D-phenylalanine (A-4166), and its stimulatory effect on insulin secretion in animals

N-[(trans-4-isopropylcyclohexyl)-carbonyl]-D-phenylalanine (A-4166) revealed a new mode of hypoglycemic action with a more rapid onset and a shorter duration of action than the sulfonylureas (SUs). Hypoglycemic mechanisms and glycemic control benefits were demonstrated in laboratory animals. The stimulatory effect of A-4166 on insulin release, in fasting dogs with a cannula into the portal vein, was more rapid than that of tolbutamide after oral administration. A-4166 stopped the stimulation of insulin secretion very quickly, whereas tolbutamide maintained an elevation in plasma insulin levels for at least 6 hours. In the case of A-4166, a counter-regulatory glucagon response was observed during recovery from hypoglycemia, but it was significantly inhibited by tolbutamide. Hyperglycemia induced by glucose loading was rapidly inhibited by A-4166 in normal rats, in genetically diabetic KK mice and in STZ-induced non-insulin-dependent diabetes mellitus (NIDDM) rats. Also, repeated administration of A-4166 for 2 weeks enhanced insulin secretion in the same manner as a single administration in normal rats. In conclusion, A-4166 is a new type of oral hypoglycemic agent, having a rapid and short-term insulin secretory effect and no suppressive effect on the hypoglycemia-induced glucagon response. Oral therapy with A-4166 would be beneficial in supplementing endogenous insulin secretion and would exert ideal glycemic control in NIDDM patients.

Glucagon: prehospital therapy for hypoglycemia

STUDY OBJECTIVE

This study evaluated the efficacy of glucagon for prehospital therapy of hypoglycemia in patients without IV access.

DESIGN

Prospective clinical trial.

SETTING

Prehospital in a busy, urban emergency medical services system.

TYPE OF PARTICIPANTS

Fifty consecutive patients presenting with documented hypoglycemia (ChemStrip BG less than or equal to 80 mg/dL) and symptoms of decreased level of consciousness, syncope, or seizure were enrolled.

MEASURES AND MAIN RESULTS

Data collected included pretreatment (ChemStrip BG) and post-treatment serum glucose (hospital assay) as well as assessment of level of consciousness by a quantitative measure, the Glasgow Coma Score, and by a qualitative scale (0 to 3). The mean pretreatment blood glucose of 33.2 +/- 23.3 mg/dL increased after treatment to 133.3 +/- 57.3 mg/dL. Qualitative level of consciousness increased from a mean of 1.26 +/- .96 to 2.42 +/- .94 and Glasgow Coma Score increased from a mean of 9.0 +/- 4.19 to 13.04 +/- 3.68. The mean time until response was 8.8 minutes in those who responded to both level of consciousness criteria 82% (41 of 50). Glucagon administered for hypoglycemia resulted in a glucose increase in 98% (49 of 50) with headache as the only side effect noted in 4% (two of 50) of patients (P less than .0001).

CONCLUSION

Glucagon is safe and effective therapy for hypoglycemia in the prehospital setting.

Comparison of tolbutamide and metformin in elderly diabetic patients

In a randomized double-blind cross-over study the efficacy, metabolic effects, and acceptability of metformin were compared with tolbutamide in 20 diabetic patients aged between 65 and 95 years. No significant differences were noted after treatment in blood glucose control (fasting plasma glucose, metformin 9.1 +/- 2.8 mmol l-1, tolbutamide 8.3 +/- 2.8 mmol l-1; mean change, metformin +1.1 mmol l-1, tolbutamide +0.02 mmol l-1, p = 0.215), domiciliary blood glucose control, fasting insulin, lactate, cholesterol or triglyceride levels. There was a significant difference in weight change between the two treatments (on metformin -2.0 kg, from 63.2 +/- 11.8 to 61.2 +/- 12.3; on tolbutamide, +1.6 kg, from 61.4 +/- 11.1 to 63.0 +/- 12.3; p = 0.001). Initial gastro-intestinal side-effects occurred in 30% of patients with metformin. These were transient and responded to temporary reduction in treatment dosage. Metformin could not be distinguished from tolbutamide in elderly diabetic patients, except in that it was associated with weight loss.

Hypoglycemia induced by excessive rebound secretion of insulin after removal of pheochromocytoma

During an 8-year-period from 1981, a total of 6 of 45 patients with pheochromocytoma developed severe hypoglycemia (plasma glucose, 12-50 mg/dl) 2-4 1/2 hours after removal of the tumor. In order to elucidate the pathogenesis of the hypoglycemic attack, the levels of plasma immunoreactive insulin (IRI) and glucose were sequentially measured at surgery in 10 patients with pheochromocytoma, from the beginning of the operation until usually 5 hours after tumor resection. The same examinations were carried out in 4 patients with primary aldosteronism and 1 patient with Cushing's syndrome as controls. The highest plasma IRI levels observed in the 2 patients with postexcisional hypoglycemia were 174 and 2,081 microU/ml and those in the 8 patients without hypoglycemia were 13-222 microU/ml (mean, 77), but they were only 14-33 microU/ml (mean, 22) in the 5 control patients. The mean of the highest plasma IRI/glucose ratios in the immediate postoperative phase was 1.37 +/- 0.87 in the 10 patients with pheochromocytoma but only 0.16 +/- 0.04 in the 5 control patients (p less than 0.01). Review of the clinical data in our series disclosed that patients with higher levels of preoperative urinary epinephrine excretion and those with either diabetes mellitus or impaired glucose tolerance tended to develop postoperative hypoglycemia. These observations suggest that endogenous insulin secretion is suppressed by increase plasma catecholamines, and that excessive rebound secretion of insulin after removal of a pheochromocytoma is a rather common phenomenon. Intravenous infusion of glucose is necessary and plasma glucose levels should be monitored after resection of a pheochromocytoma.

Symptomatic hypoglycemia secondary to a glipizide-trimethoprim/sulfamethoxazole drug interaction

Sulfonamides have been reported to augment the hypoglycemic effects of chlorpropamide, glyburide, and tolbutamide. This case report is the first to describe a possible interaction with glipizide. An 83-year-old man receiving glipizide 10 mg bid developed symptomatic hypoglycemia within three days of adding trimethoprim/sulfamethoxazole (TMP/SMX) to his regimen. All other factors, including laboratory data, dietary intake, activity level, and concurrent use of other medications, were stable and noncontributory. This patient may have been at increased risk for this interaction secondary to his age and history of alcohol abuse. The mechanism of the interaction is probably inhibition of glipizide metabolism rather than protein-binding displacement. This case suggests that, when TMP/SMX is combined with glipizide, patients should be closely monitored, especially those at high risk for hypoglycemia.

Does ethanol intake interfere with the evaluation of glycated hemoglobins?

Ethanol and/or its metabolites interfere with the chromatographic assay of glycated hemoglobins. Fasting plasma glucose, blood ethanol, HbA(1), HbA(1c), HbA(1a+b), MCV and GGT were determined in 22 control subjects; 22 alcoholics, 22 diabetic patients and 22 alcoholic diabetic patients. Fasting plasma glucose and all hemoglobin fractions were lower in alcoholic subjects and, except for HbA(1a+b), higher in diabetic patients and in alcoholic diabetic patients. HbA(1), and HbA(1c) correlated well with plasma glucose but not with blood ethanol, MCV and GGT. Glycated hemoglobin was not found to be a useful marker for alcohol abuse. With the chromatographic method we used, the evaluation of glycated hemoglobin fractions, chiefly HbA(1c), confirms its usefulness in monitoring the metabolic control of diabetic subjects, even in case of ethanol abuse.

Hypoglycemia: a pathophysiologic approach

An exploration of the factors that sustain glucose levels in the normal fasting subject reveals that the single major component is conservation of glucose rather than gluconeogenesis. Conservation is achieved by recycling of glucose carbon as lactate, pyruvate and alanine, and a profound decrease in the oxidation of glucose by the brain brought about by the provision and use of ketones. What glucose continues to be oxidized is for the most part formed from glycerol. Gluconeogenesis from protein plays little part in the process. Fasting hypoglycemia results from disorders affecting either one of the two critical sustaining factors--the recycling process or the availability and use of ketones. Individual hypoglycemic entities are examined against this background.