The care of pregestational and gestational diabetes and drug metabolism considerations.

Normal pregnancy development involves gradual decline in insulin sensitivity, which sometimes requires pharmacotherapy. Insulin is the drug of choice for gestational and pregestational diabetes. Metabolism of traditional insulins results in inadequate onset and duration of action and marked peak activity. These properties increase risk of excessive glucose excursions, which are especially undesirable during pregnancy. Insulin analogs have been emerging as a safer and more effective treatment of diabetes during pregnancy. Areas covered: This manuscript reviews currently used antihyperglycemic agents: fast and long-acting insulins, metformin and glyburide. Trials demonstrating their efficacy and safety during pregnancy are described. Certain drug metabolism considerations (e.g. affinity to IGF-1) are emphasized. Expert opinion: The theories that insulin analogs bind to immunoglobulin and cross placenta have been disproved. Lispro, aspart, glargine and detemir do not transfer across the placenta and do not result in adverse maternal and neonatal outcomes. In addition, favorable pharmacokinetic profiles (rapid onset and 24-hour near peakless activity) substantially reduce blood glucose variability including hypoglycemia. We believe that insulin analogs should be given strong consideration for the treatment of diabetes during pregnancy. Metformin has also proven to be safe and may be considered as an initial single agent for milder gestational diabetes.