Insulins have hitherto been distinguished as clear (short-acting) and cloudy (long-acting). However the introduction of glargine, which is a clear long-acting insulin, has prompted the need for reclassification. In view of the increasing emphasis on intensive insulin therapy using basal-bolus regimens, a new, simple, pragmatic classification is suggested in which insulins are categorised according to the timing and purpose of administration: basal (maintenance), bolus (meal) and biphasic (mixed).
