Many drugs affect blood glucose levels. Among those are antipsychotics, immunosuppressants, corticosteroids and thiazide diuretics. Benefits of using these drugs often outweigh the risks. Their use must be evaluated by healthcare personnel. Sometimes doses must be reduced or stopped. The continued treatment with these medicines sometimes contribute to the initiation of non reversible diabetes. Many times the continued use of these medications is necessary. Increases in blood glucose are usually very small.