Sulphonylureas short-acting

Acetazolamide is a carbonic anhydrase inhibitor that reduces aqueous humour production and is therefore indicated in glaucoma to reduce the intraocular pressure. Salbutamol is a selective, short-acting beta2-agonist used as a bronchodilator in asthma. Tolbutamide is a short-acting sulphonylurea used in type 2 (non-insulin dependent) diabetes mellitus. Chlorpromazine is an aliphatic neuroleptic antipsychotic drug used in schizophrenia. Zafirlukast is a leukotriene-receptor antagonist that is indicated in the prophylaxis of asthma but should not be used to relieve acute severe asthma. 

Tolbutamide is a short-acting agent. It is rapidly metabolized in the liver with an elimination half-life of 6-10 hours. Protein binding is more than 90%. It has the advantages of causing less frequently and less serious hypoglycemia than the more potent sulphonylureas. 

Repaglinide is a very short-acting oral hypogly-caemic agent whose action, like the sulphonylureas, is mediated through blockade of ATP-dependent potassium channels. It affects only postprandial insulin profiles, and should in theory reduce risk of hypoglycaemia. 

In many NIDDM patients once daily intermediate- or long-acting insulin may be adequate to render them asymptomatic, avoid the risk of nocturnal hypoglycaemic episodes (Bilous and Alberti, 1990) and produce basal normoglycaemia. A combination of intermediate-acting insulin and sulphonylureas is possible, the patients own B-cells providing the meal-time spikes. Alternatively one or two injections of a mixture of short- and intermediate-acting insulin daily is sufficient for metabolic control. In elderly... 

NPH insulin or long-acting insulin analogues at bedtime or mixed short- and long-acting insulin analogues at the main meals 2—3 times a day should be added when HbAj is >7.0% despite maximal dose of OADs. At the start of insulin treatment, obese patients stop the sulphonylurea/meglitinide and the lean patients stop metformin. 

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