Hypoglycaemic unawareness Health Dictionary

Hypoglycaemic Unawareness: From 1 Different Sources


a serious condition in which a person with diabetes loses the earliest warning signs of an approaching hypoglycaemic episode. Such people may suffer a severe attack of hypoglycaemia, with confusion, seizures, or even coma and death, because they fail to take the necessary measures to abort the episode. The condition is more common in longstanding diabetes and in those who experience frequent hypoglycaemic episodes. People with hypoglycaemic unawareness should not drive. Some awareness of hypoglycaemia may be restored by careful avoidance of more episodes, ensuring that the blood glucose level never falls below 4 mmol/l.
Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Hypoglycaemic Agents

These oral agents reduce the excessive amounts of GLUCOSE in the blood (HYPERGLYCAEMIA) in people with type 2 (INSULIN-resistant) diabetes (see DIABETES MELLITUS). Although the various drugs act di?erently, most depend on a supply of endogenous (secreted by the PANCREAS) insulin. Thus they are of no value in treating patients with type 1 diabetes (insulin-dependent diabetes mellitus (IDDM), in which the pancreas produces little or no insulin and the patient’s condition is stabilised using insulin injections). The traditional oral hypoglycaemic drugs have been the sulphonylureas and biguanides; new agents are now available – for example, thiazolidine-diones (insulin-enhancing agents) and alpha-glucosidase inhibitors, which delay the digestion of CARBOHYDRATE and the absorption of glucose. Hypoglycaemic agents should not be prescribed until diabetic patients have been shown not to respond adequately to at least three months’ restriction of energy and carbohydrate intake.

Sulphonylureas The main group of hypoglycaemic agents, these act on the beta cells to stimulate insulin release; consequently they are e?ective only when there is some residual pancreatic beta-cell activity (see INSULIN). They also act on peripheral tissues to increase sensitivity, although this is less important. All sulphonylureas may lead to HYPOGLYCAEMIA four hours or more after food, but this is relatively uncommon, and usually an indication of overdose.

There are several di?erent sulphonylureas; apart from some di?erences in their duration or action (and hence in their suitability for individual patients) there is little di?erence in their e?ectiveness. Only chlorpropamide has appreciably more side-effects – mainly because of its prolonged duration of action and consequent risk of hypoglycaemia. There is also the common and unpleasant chlorpropamide/ alcohol-?ush phenomenon when the patient takes alcohol. Selection of an individual sulphonylurea depends on the patient’s age and renal function, and often just on personal preference. Elderly patients are particularly prone to the risks of hypoglycaemia when long-acting drugs are used. In these patients chlorpropamide, and preferably glibenclamide, should be avoided and replaced by others such as gliclazide or tolbutamide.

These drugs may cause weight gain and are indicated only if poor control persists despite adequate attempts at dieting. They should not be used during breast feeding, and caution is necessary in the elderly and in those with renal or hepatic insu?ciency. They should also be avoided in porphyria (see PORPHYRIAS). During surgery and intercurrent illness (such as myocardial infarction, COMA, infection and trauma), insulin therapy should be temporarily substituted. Insulin is generally used during pregnancy and should be used in the presence of ketoacidosis.

Side-effects Chie?y gastrointestinal disturbances and headache; these are generally mild and infrequent. After drinking alcohol, chlorpropamide may cause facial ?ushing. It also may enhance the action of antidiuretic hormone (see VASOPRESSIN), very rarely causing HYPONATRAEMIA.

Sensitivity reactions are very rare, usually occurring in the ?rst six to eight weeks of therapy. They include transient rashes which rarely progress to erythema multiforme (see under ERYTHEMA) and exfoliate DERMATITIS, fever and jaundice; chlorpropamide may also occasionally result in photosensitivity. Rare blood disorders include THROMBOCYTOPENIA, AGRANULOCYTOSIS and aplastic ANAEMIA.

Biguanides Metformin, the only available member of this group, acts by reducing GLUCONEOGENESIS and by increasing peripheral utilisation of glucose. It can act only if there is some residual insulin activity, hence it is only of value in the treatment of non-insulin dependent (type 2) diabetics. It may be used alone or with a sulphonylurea, and is indicated when strict dieting and sulphonylurea treatment have failed to control the diabetes. It is particularly valuable in overweight patients, in whom it may be used ?rst. Metformin has several advantages: hypoglycaemia is not usually a problem; weight gain is uncommon; and plasma insulin levels are lowered. Gastrointestinal side-effects are initially common and persistent in some patients, especially when high doses are being taken. Lactic acidosis is a rarely seen hazard occurring in patients with renal impairment, in whom metformin should not be used.

Other antidiabetics Acarbose is an inhibitor of intestinal alpha glucosidases (enzymes that process GLUCOSIDES), delaying the digestion of starch and sucrose, and hence the increase in blood glucose concentrations after a meal containing carbohydrate. It has been introduced for the treatment of type 2 patients inadequately controlled by diet or diet with oral hypoglycaemics.

Guar gum, if taken in adequate doses, acts by delaying carbohydrate absorption, and therefore reducing the postprandial blood glucose levels. It is also used to relieve symptoms of the DUMPING SYNDROME.... hypoglycaemic agents

Hypoglycaemic

A herb with ability to lower blood-sugar levels. Of value in diabetes mellitis. Bean pods, Bladderwrack, Goat’s Rue, Jambul, Nettles, Onion, Fenugreek seeds, Olive leaves, Periwinkle (Vinca rosea), Sweet Sumach.

Eucalyptus, (R. Benigni et col Planti Medicinali, 1962, vol 1, 562) Reduction of blood sugar by Garlic has been reported. ... hypoglycaemic

Oral Hypoglycaemic Drug

(oral antihyperglycaemic drug) one of the group of drugs that reduce the level of glucose in the blood and are taken by mouth for the treatment of type 2 *diabetes mellitus. They include the *sulphonylurea group (e.g. glibenclamide, gliclazide), metformin (a *biguanide), *alpha-glucosidase inhibitors, *meglitinides, *thiazolidinediones, *DPP-IV inhibitors, and *SGLT-2 inhibitors.... oral hypoglycaemic drug

Hypoglycaemic Coma

Hypoglycaemia or low blood sugar occurs when a patient with DIABETES MELLITUS suffers an imbalance between carbohydrate/glucose intake and INSULIN dosage. If there is more insulin than is needed to help metabolise the available carbohydrate, it causes a range of symptoms such as sweating, trembling, pounding heartbeat, anxiety, hunger, nausea, tiredness and headache. If the situation is not quickly remedied by taking oral sugar – or, if severe, giving glucose by injection – the patient may become confused, drowsy and uncoordinated, ?nally lapsing into a COMA. Hypoglycaemia is infrequent in people whose diabetes is controlled with diet and oral HYPOGLYCAEMIC AGENTS.

Treatment of acute hypoglycaemia depends upon the severity of the condition. Oral carbohydrate, such as a sugary drink or chocolate, may be e?ective if the patient is conscious enough to swallow; if not, glucose or GLUCAGON by injection will be required. Comatose patients who recover after an injection should then be given oral carbohydrates. An occasional but dangerous complication of coma is cerebral oedema (see BRAIN, DISEASES OF – Cerebral oedema), and this should be considered if coma persists. Emergency treatment in hospital is then needed. When the patient has recovered, management of his or her diabetes should be assessed in order to prevent further hypoglycaemic attacks.... hypoglycaemic coma




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