Mounjaro interactions to avoid

Drug interactions | Food interactions | Other interactions | Avoiding interactions | When to see a doctor

Mounjaro (tirzepatide) is gaining popularity as a treatment for Type 2 diabetes mellitus and off-label for weight management. In fact, in late 2023, its manufacturer, Eli Lilly, released another brand form of tirzepatide, Zepbound, with Food and Drug Administration (FDA) approval for weight loss. Costs are a concern with these drugs, but coupons for Mounjaro and Zepbound and a SingleCare prescription discount card can help. There are some contraindications with Mounjaro, such as when it should not be used and situations that require caution. Knowing Mounjaro’s interactions with health conditions and some important drug interactions involving tirzepatide is essential to reducing your risk of adverse reactions to the medication.

RELATED: Mounjaro side effects and how to avoid them

Mounjaro drug interactions

Mounjaro does not have a ton of drug interactions, thankfully. The ones that it does have are important, though.

Hypoglycemic agents

Mounjaro acts as a glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) agonist, and by stimulating those receptors, it increases insulin secretion only when glucose levels are high, reduces glucagon (a hormone that can raise sugar levels) secretion, and slows gastrointestinal motility which reduces appetite and food intake. These mechanisms reduce the incidence of high blood sugar (hyperglycemia) and help us lose weight. Mounjaro’s mechanisms do not cause hypoglycemia on their own, so tirzepatide can be used for weight loss even when people do not have diabetes.

However, taking Mounjaro can increase the chance of having hypoglycemia if you are taking a medication that lowers blood sugar directly. Insulins and the family of sulfonylureas, oral medications for diabetes, are the two big culprits for hypoglycemia to be mindful of. More frequent blood glucose monitoring may be advised if you are taking Mounjaro along with insulin or a sulfonylurea, such as any of the following:

• Glipizide ER (glipizide extended-release)anticoagulant
• Glimepiride
• Glyburide
• Humalog Kwikpen (insulin lispro)
• Novolog FlexPen (insulin aspart)
• Lantus Solostar (glargine insulin) 
• Levemir FlexPen (insulin detemir)

To a lesser extent, other drug classes can magnify the hypoglycemia risk as well when taken with these other agents. The drug classes include selective serotonin reuptake inhibitors (SSRIs), quinolone antibiotics, monoamine oxidase inhibitors (MAOIs), and beta blockers. Taking them along with diabetes medications could require you to check your blood sugar levels more often and watch more closely for hypoglycemia symptoms, like weakness, dizziness, sweating, confusion, and shakiness.

Oral contraceptive pills

Slowing down how fast our stomach empties and intestines move their contents along is part of how Mounjaro works. Because Mounjaro causes delayed gastric emptying, it may lessen the effectiveness of oral hormonal contraceptives. This can affect how other oral medications are absorbed and how effective they are. In the setting of oral contraceptive pills, this can make them less effective and put users at risk of unintended pregnancy.

One way to avoid this issue is to change to an alternative to birth control pills. Several birth control methods, such as contraceptive patches, injections, vaginal rings, and intrauterine devices, are not affected by Mounjaro. Talk to your healthcare team about what option is best for you. Suppose you decide to stay on oral contraceptive pills. In that case, you may be advised to use additional barrier methods of contraception, such as condoms, for the first month after starting Mounjaro and after any dose increase. The interaction is felt to be most impactful at these times.

Warfarin

Jantoven (warfarin) thins the blood by blocking vitamin K from helping to build blood-clotting proteins. It is a touchy medicine with numerous food and drug interactions. The degree of blood thinning that it produces must be closely monitored. Monitoring may need to be more frequent if you take Mounjaro with warfarin because Mounjaro could affect the absorption of the anticoagulant. Too little warfarin effect and blood clot risk rises; too much warfarin effect and bleeding risk rises. Your doctor can guide you on how frequently to monitor it.

RELATED: Mounjaro (tirzepatide) alternatives: What can I take instead of Mounjaro?

Mounjaro food interactions

Mounjaro is an injection that is taken once a week. Like other GLP-1 agonists injected subcutaneously into the thigh, abdomen, or upper arm, it does not matter if you take it with or without food. These agents include: 

• Wegovy (semaglutide)
• Ozempic (semaglutide)
• Victoza (liraglutide)
• Saxenda (liraglutide)
• Trulicity (dulaglutide). 

Conversely, Rybelsus is an oral formulation of semaglutide that is best taken without food. You should not double up on GLP-1 action by taking Mounjaro with any other GLP-1 agonist, injectable or oral.

Other Mounjaro interactions

Mounjaro’s interactions with other medical conditions may be the most important to be aware of, not because of frequency but because of severity. Identifying them ahead of time can steer you clear of even starting Mounjaro.

Mounjaro and alcohol

Although Mounjaro does not directly interact with alcohol, both substances have a propensity for causing pancreatitis. This inflammatory condition of the pancreas can lead to severe abdominal pain and a critical illness. Limiting alcohol intake while taking Mounjaro may be best.

RELATED: Can you drink while taking Mounjaro?

Mounjaro and pancreatitis

The link between GLP-1 receptor agonist use and pancreatitis is not defined yet, but case reports have raised a red flag. Nonetheless, because pancreatitis can be a life-threatening condition, Mounjaro may need to be avoided if you have a history of pancreatitis in the past or are at high risk due to high triglycerides or alcohol use.

Watch for symptoms of pancreatitis while taking tirzepatide. The signs typically include abdominal pain and nausea. Common adverse effects of Mounjaro include abdominal pain, nausea, vomiting, diarrhea, and constipation, so it can be challenging to determine what is going on. Additionally, GLP-1 agonists like Mounjaro have been linked to gallbladder disease that can have similar symptoms. If you feel this way, get medical advice from your healthcare provider immediately, or seek urgent medical attention if symptoms are severe.

Mounjaro and thyroid cancer

The FDA has placed a warning label on Mounjaro, calling attention to studies in rats showing higher rates of thyroid C-cell tumors, also known as medullary thyroid carcinoma (MTC). It is a rare form of cancer in humans and is most often seen in individuals with Multiple endocrine neoplasia syndrome type 2 (MEN2). We do not know if tirzepatide is associated with MTC in humans. Still, according to the FDA’s boxed warning, anyone with a history of MTC or a personal or family history of MEN2 should avoid it.

Mounjaro and gastroparesis

Patients with gastroparesis experience feeling full or nauseated quickly with meals as a result of their stomach not emptying properly. Mounjaro slows gastric motility, making matters worse for those with gastroparesis. Your medical provider may advise you to avoid Mounjaro or may suggest certain precautions for you to take with the drug.

Mounjaro and diabetic retinopathy

Uncontrolled diabetes mellitus can damage the retina of the eyes, a condition known as diabetic retinopathy. Vision loss with this condition results from high sugars, causing damage to blood vessels in the retina, and curiously, rapid improvement in sugar levels has also been associated with the progression of the disease. Cases of diabetic retinopathy with tirzepatide use were noted in a 2021 study. This is an issue that should be discussed with the prescribing healthcare professional before starting Mounjaro, particularly if you have pre-existing diabetic retinopathy.

Mounjaro and pregnancy and breastfeeding

Mounjaro could be harmful during pregnancy, and not much information from clinical trials is available. Due to the possible harms, one should not use Mounjaro during pregnancy. Risks during breastfeeding are also unknown. Ask your healthcare provider what precautions to take against becoming pregnant while on Mounjaro and whether an alternative should be used while breastfeeding.

How to minimize Mounjaro interactions

Reducing your risk of Mounjaro interactions is the joint responsibility of you, your healthcare provider, and your pharmacist. The drug information in the medication guide accompanying Mounjaro will also provide important and valuable information. You can help by getting everyone on your healthcare team on the same page, meaning ensuring everyone has the same information. Start by making a list of your prescription drugs, over-the-counter (OTC) meds, and supplements, and then keep it updated when any change occurs. Do the same by creating a list of your medical problems. Share these records regularly with all members of your healthcare team. It is best to have everyone on the lookout for interactions. 

When to talk to a healthcare provider about Mounjaro interactions

There is no time like the present to start a dialogue with your healthcare provider about Mounjaro interactions. Ideally, the conversation occurs before starting the drug, but there is always time to ask. Directly questioning if Mounjaro interacts with any other medicine on your list or with your health problems is a great way to engage with your care. Now that you know some of the specific interactions, you are better prepared for the discussion.