Glibenclamide Health Dictionary

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

(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

n. one of a group of *oral hypoglycaemic drugs, derived from a *sulphonamide, that are used in the treatment of type 2 diabetes mellitus; they act by stimulating the islet cells in the pancreas to produce more insulin. The group includes *glibenclamide, *gliclazide, and *tolbutamide. Side-effects, such as nausea, vomiting, and diarrhoea, are usually mild.... sulphonylurea

Sulphonylureas are sulphonamide derivatives which lower the blood sugar when they are given by mouth by enhancing the production of INSULIN. They are e?ective in treating DIABETES MELLITUS only when some residual pancreatic beta-cell function is present. All may lead to HYPOGLYCAEMIA if given in overdose and this is particularly common when long-acting sulphonylureas are given to elderly patients. There is no evidence for any di?erence in the e?ectiveness of the various sulphonylureas. TOLBUTAMIDE was the ?rst of the sulphonlyurea drugs; it has a short duration of action and is usually given twice daily. CHLORPROPAMIDE has a more prolonged action and only needs to be given once daily, but its prolonged action causes more side-effects – including sensitivity reactions. Other oral hypoglycaemic agents of this family include glibenclamide, which has a duration of action intermediate between tolbutamide and chlorpropamide and also produces side-effects (in about 30 per cent of outpatients, according to a recent study). Other sulphonlyureas include acetohexamide, glibornuride, gliclazide, glipizide, gliquidone and tolazamide. Glymidine is a related compound with a similar action to the sulphonylureas. It is particularly useful in patients who are hypersensitive to sulphonylureas.

Sulphonylureas are best avoided in patients who are overweight, as they tend to stimulate the appetite and aggravate obesity. They should be used with caution in patients with hepatic or renal disease. Side-effects are infrequent and usually not severe, the most common being epigastric discomfort with occasional nausea, vomiting and anorexia. In about 10 per cent of patients, chlorpropamide and tolbutamide may cause facial ?ushing after drinking alcohol. Some patients are hypersensitive to oral hypoglycaemic agents and develop rashes which may progress to ERYTHEMA multi-forme and exfoliative DERMATITIS. These reactions usually appear in the ?rst 6–8 weeks of treatment.... sulphonylureas

A group of drugs used to treat diabetes mellitus, in which a lack of insulin, or resistance to its actions, results in raised blood glucose levels. A wide range of antidiabetics are used to keep the blood glucose level as close to normal as possible, and consequently reduce the risk of complications such as vascular (blood vessel) disease.

Antidiabetic drugs include insulin, which must be administered by injection, and oral hypoglycaemics such as glibenclamide and metformin. Acarbose and guar gum reduce or slow absorption of carbohydrate from the intestines after meals. Repaglinide stimulates insulin release from the pancreas for a short time and may be taken directly before meals. Rosiglitazone reduces resistance to the effects of insulin in the tissues and may be used together with other hypoglycaemics.... antidiabetic drugs