For type 2 diabetes patients who require an injectable drug, GLP-1-based drugs are preferred over insulin

That's a pretty big change:

Diabetes Guidelines Updated: For patients with type 2 diabetes who require an injectable drug, a glucagon-like peptide 1 receptor agonist is preferred over insulin. https://buff.ly/2T0Kowc

Glucagon-like peptide-1 (GLP-1)-based therapies (eg, GLP-1 receptor agonists, dipeptidyl peptidase-4 [DPP-4] inhibitors) affect glucose control through several mechanisms, including:

- enhancement of glucose-dependent insulin secretion
- slowed gastric emptying
- reduction of postprandial glucagon and food intake

These agents do not usually cause hypoglycemia.

Short-acting GLP-1 receptor agonists have an effect on postprandial hyperglycemia and gastric emptying:

- Exenatide twice daily. Exendin-4 is a naturally occurring component of the Gila monster lizard saliva and shares 53 percent sequence identity with GLP-1. Exenatide (half-life 2.4 hours) is synthetic exendin-4. Brand Names: Bydureon; Byetta Pen.

- Lixisenatide is a GLP-1 receptor agonist that shares some structural elements with exendin-4. Compared with native GLP-1, it has a prolonged half-life (2.7 to 4.3 hours). Brand Names: Adlyxin.

Long-acting GLP-1 receptor agonists have a greater resistance to dipeptidyl peptidase-4 (DPP-4) degradation. They activate the GLP-1 receptor continuously and have a prolonged half-life, thus allowing for once-daily and even once-weekly subcutaneous injection. They have a marked effect on fasting glucose.

- Exenatide once weekly is a sustained-release formulation of the short-acting subcutaneous exenatide.

- Liraglutide is GLP-1 receptor agonist which binds to serum albumin, resulting in slower degradation (half-life 11 to 15 hours) and allowing for once-daily, subcutaneous dosing. Brand Names: Saxenda; Victoza.

- Dulaglutide is a long-acting GLP-1 receptor agonist with structural modifications to prevent degradation by DPP-4 and to prolong its half-life. The half-life of dulaglutide is approximately five days, which allows for once-weekly administration. Brand Names: Trulicity/

- Semaglutide is a long-acting GLP-1 receptor agonist (94% homology with native human GLP-1) with structural modifications to reduce renal clearance and decrease degradation by DPP-4, resulting in half-life 155 to 184 hours, thus allowing for once-weekly, subcutaneous (or potentially once-daily, oral) dosing. Semaglutide is the only GLP-1 receptor agonist that has shown to be effective when given orally. Brand Names: Ozempic.

Based on studies, liraglutide or semaglutide are the preferred options.

The medications have a US Boxed Warning for Thyroid C-cell tumor risk.

References:

https://www.jwatch.org/fw114893/2018/12/19/diabetes-guidelines-updated
http://care.diabetesjournals.org/content/42/Supplement_1
https://www.uptodate.com/contents/glucagon-like-peptide-1-receptor-agonists-for-the-treatment-of-type-2-diabetes-mellitus