Mechanism of Action（作用机理）
Tirzepatide is a dual-agonist for both the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. It mimics the actions of these two incretin hormones to enhance glucose homeostasis and appetite regulation:
- GIP Receptor Activation: Tirzepatide binds to the GIP receptor, stimulating insulin secretion in a glucose-dependent manner, which helps lower blood glucose levels. It also promotes the clearance of dietary triglycerides and enhances lipid metabolism in adipose tissue.
- GLP-1 Receptor Activation: It activates the GLP-1 receptor, leading to additional insulin secretion, suppression of glucagon release, and slowing of gastric emptying. This interaction also reduces appetite and food intake by acting on the central nervous system.
- Synergistic Effects: By activating both receptors simultaneously, tirzepatide provides a more potent and comprehensive effect on glucose control and weight management compared to single-agonist therapies.
Applications（应用）
- Type 2 Diabetes Management: Tirzepatide is approved as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes.
- Weight Management: It is also indicated for chronic weight management in individuals with obesity or overweight with at least one weight-related comorbidity. Clinical trials have shown significant weight loss benefits.
- Other Potential Uses: Ongoing studies are exploring its potential in non-alcoholic steatohepatitis (NASH), heart failure with preserved ejection fraction (HFpEF), obstructive sleep apnea (OSA), and chronic kidney disease (CKD).
Dosage Instructions（用法用量）
- Initial Dose: The recommended starting dose is 2.5 mg once weekly.
- Titration: The dose can be increased to 5 mg, 7.5 mg, or 10 mg once weekly, depending on the patient's glycemic response and tolerability.
- Injection Instructions: Tirzepatide is administered subcutaneously in the abdomen, thigh, or upper arm. Rotate injection sites to avoid lipodystrophy.
- Missed Dose: If a dose is missed, administer as soon as possible within 3 days. If more than 3 days have passed, skip the missed dose and resume the regular schedule.
Storage（保存）
- Unopened Pens: Store refrigerated at 2°C to 8°C (36°F to 46°F). Do not freeze.
- Opened Pens: Once opened, pens can be stored at room temperature (not exceeding 30°C/86°F) for up to 8 weeks.
- Protection from Light and Heat: Keep the medication away from direct sunlight and high temperatures.
