Common drugs used to treat Type 1 diabetes include insulin and pramlintide, according to Healthline. Insulin is sometimes used to treat Type 2 diabetes as well, along with drugs called alpha-glucosidase inhibitors, such as Precose and Glyset.
Another common drug used to treat Type 2 diabetes is metformin, states Healthline. Metformin is classified as a biguanide, which decreases glucose production in a person's liver. Metformin is sometimes combined with other medicines to treat Type 2 diabetes, such as metformin-canagliflozin and metformin-rosiglitazone. Additionally, drugs classified as a dopamine agonist are used to treat diabetes. While as of 2015, the actions of these drugs in diabetics are unknown, it is thought that they affect a person's circadian rhythm, which may have a positive effect on obesity and insulin resistance.