What is Tirzepatide?

Approved in March 2022 by the FDA as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. Tirzepatide belongs to a class of drugs known as dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 receptor agonists (GLP-1 RA). It is being studied for its potential use in the treatment of type 2 diabetes mellitus (T2DM) and obesity.

How does Tirzepatide work?

Tirzepatide works through a dual mechanism of action targeting two important pathways involved in blood sugar regulation: the glucose-dependent insulinotropic polypeptide (GIP) pathway and the glucagon-like peptide-1 (GLP-1) pathway. It is administered via subcutaneous injection and is being investigated to evaluate its safety and efficacy for the treatment of type 2 diabetes mellitus and obesity.

1. GIP Pathway: Tirzepatide activates the GIP receptor, which stimulates the release of insulin from pancreatic beta cells in response to elevated blood sugar levels. This helps to reduce blood sugar levels by increasing the uptake of glucose into cells and inhibiting the release of glucagon, a hormone that raises blood sugar levels.

2. GLP-1 Pathway: Tirzepatide also activates the GLP-1 receptor, leading to several beneficial effects:

• Increased insulin secretion: Tirzepatide enhances insulin secretion in response to elevated blood sugar levels, further reducing blood sugar levels.
• Slowed gastric emptying: Tirzepatide slows down the emptying of the stomach, which helps to control postprandial (after-meal) blood sugar spikes.
• Suppressed appetite: Activation of the GLP-1 receptor in the brain reduces appetite and food intake, leading to weight loss.

As a GIP and GLP-1 receptor agonist, Tirzepatide is a 39 amino-acid modified peptide with a C20 fatty diacid moiety that enables albumin binding and prolongs the half-life. Tirzepatide selectively binds to and activates both the GIP and GLP-1 receptors, the targets for native GIP and GLP-1. At therapeutic doses, it acts on centers in the brain and suppresses appetite.
Used in conjunction with diet and exercise, Tirzepatide helps patients adhere to a reduced-calorie diet, enhancing the weight loss process.

Potential Side Effects

The most common side effects may include nausea, diarrhea, vomiting, constipation, stomach pain, headache, fatigue, dizziness, bloating, gas and heartburn. More serious side effects may include: –

• Pancreatitis (inflammation of the pancreas)
• Gallbladder problems
• Kidney problem/failure
• Serious allergic reactions
• Increased heart rate
• Depression