CG, a 58-year-old male with type 2 diabetes presents with a new prescription for tirzepatide (pen) to add to his current glucose-lowering regimen. He has several questions about the proper storage of all of his medications.

Past medical history:

Hypertension: Losartan 25mg orally daily

Type 2 Diabetes: Lantus SoloStar pens 40 units subcutaneously daily

Hyperlipidemia: Rosuvastatin 20mg orally at bedtime

Which of the following would you recommend concerning medication storage? Select all that apply.

A. Tirzepatide pens can be frozen for long-term storage up to 6 months

B. Tirzepatide pens can be stored at room temperature for up to 21 days after first use

C. Opened Lantus SoloStar pens may be stored at room temperature for a maximum of 21 days

D. Unopened Lantus SoloStar pens should be stored in the refrigerator until the expiration date

E. Lantus SoloStar pens should be kept in the refrigerator after opening

Answer with rationale:

Mounjaro (tirzepatide) and insulin are both injectable medications used to manage type 2 diabetes, and have different storage requirements. Mounjaro is a relatively newer once-weekly medication that mimics the hormones GLP-1 and GIP, which help regulate blood sugar levels by increasing insulin secretion, reducing the amount of glucose produced by the liver, and slowing down gastric emptying. This combination helps lower blood sugar and also promotes weight loss, which can be an important factor in managing type 2 diabetes effectively. Mounjaro is typically prescribed when lifestyle changes and other oral medications aren’t enough to control blood sugar levels. Of note, the same medication (tirzepatide) when used to manage obesity has a brand name of Zepbound. 

Insulin is a hormone that helps move glucose from the bloodstream into the body’s cells for energy that is an absolute necessity for patients with type 1 diabetes. People with type 2 diabetes may need insulin therapy when their pancreas can’t produce enough on its own, especially in later stages of the disease. Insulin can be fast-acting, intermediate, or long-acting, and it’s often used when blood sugar levels remain high despite other treatments. Lantus is the brand for insulin glargine, and is considered a long-acting or basal insulin. While insulin is very effective at controlling glucose, it can also lead to weight gain and low blood sugar episodes, which is why newer options like Mounjaro or Ozempic are becoming more popular as alternatives in appropriate patients.

Insulin products and newer agents such as Mounjaro are administered subcutaneously and have very specific storage requirements. These can vary based on the specific dosage form as well (e.g. vial vs. pen). These are important counseling points for patients to receive from pharmacists to ensure safe and effective therapy. 

Answer A is incorrect: Mounjaro should never be frozen. It was not designed to hold its stability after being frozen, and it should be discarded if ever frozen.

Answer B is correct: An open pen (or vial) of Mounjaro can be stored at room temperature for a maximum of 21 days. 

Answer C is incorrect: Lantus SoloStar pens should be stored at room temperature once used, but they can be used for up to 28 days after opening.

Answer D is correct: Lantus SoloStar pens should be stored in the fridge until use, and can last until the manufacturer expiration date on the pen.

Answer E is incorrect: Lantus SoloStar pens should be stored at room temperature after opening. However, the Lantus vials can be stored at room temperature OR in the fridge, for a maximum of 28 days after first use for either storage method.

Brand/generics Covered:

Tirzepatide (Mounjaro), Insulin glargine (Lantus SoloStar pens and vials), Losartan (Cozaar), Rosuvastatin (Crestor)

Naplex Content Domains Covered

2.D - Medication handling, storage… temperature control

3.E.2 - Patient education: medication storage