DRUG ADMINISTRATION IN PATIENTS WITH DIABETES-MELLITUS - SAFETY CONSIDERATIONS

Diabetes mellitus is associated with alterations in a number of key me tabolic pathways. Despite theoretical concerns, clinically significant alterations in the pharmacokinetic properties of commonly prescribed drugs are relatively uncommon, Indeed, dose adjustment is rarely requi red in the setting of well controlled diabetes mellitus. However, sign ificant alterations in drug handling may occur in the context of poor metabolic control or in the presence of complications such as nephropa thy. Metformin use may be complicated by lactic acidosis. Fortunately, this is a rare occurrence providing that the agent is not used in cir cumstances in which it is contraindicated. Indeed, the risk of death f rom metformin-related lactic acidosis is similar in magnitude to the r isk of death related to hypoglycaemia in sulphonylurea-treated patient s. The novel hypoglycaemic agent troglitazone may be associated with a bnormalities in liver function in approximately 2% of patients. Discon tinuation of treatment is followed by normalisation of liver enzyme le vels. Current prescribing information recommends frequent monitoring o f liver function tests and immediate cessation of therapy if abnormali ties develop. In addition to disturbances in intermediary metabolism, diabetes mellitus may also lead to chronic microvascular and marcovasc ular complications. Thus, in addition to the use of drugs for the cont rol of blood glucose, patients with diabetes mellitus are likely to be prescribed medication for associated conditions such as cardiovascula r disease. Such medication includes the ACE inhibitors which are contr aindicated in patients with bilateral renal artery stenosis. This comp lication may be theoretically more common in patients with diabetes me llitus because of accelerated atherosclerosis. However, in clinical pr actice this is an uncommon occurrence in the absence of clinical featu res that should alert the treating clinician that an individual patien t might be at high risk. Although caution should also be used with bet a-blocker therapy in patients with diabetes mellitus, current evidence suggests that, like ACE inhibitors, these drugs may be particularly u seful in this patient group.