Other medicines alongside

Blood pressure medicines

Low blood pressure and dizziness were more frequent on these medicines, more so in people taking blood pressure medicines: with tirzepatide, 2.2% of those on them against 1.2% of those who weren't. Vomiting and diarrhea add to it.

Insulin and sulfonylureas

Low blood sugar is more likely when these medicines are combined with insulin or a sulfonylurea. In people with type 2 diabetes on tirzepatide, it happened in 10.3% of those also on a sulfonylurea against 2.1% of those who weren't. The labels leave any change to insulin or sulfonylureas to your doctor.

Tablets that need to work fast

Because these medicines slow the stomach, some tablets can be absorbed later. The EU tirzepatide label gives paracetamol as an example: after a dose of tirzepatide, its peak level fell by half and came an hour later, an effect that was gone after 4 weekly doses. For medicines with a narrow margin, like warfarin and digoxin, the labels ask for closer checks at the start and with each dose increase.

Thyroid tablets and the semaglutide tablet

If you take the daily semaglutide tablet, the label reports that exposure to levothyroxine went up by 33%. Tell the doctor who looks after your thyroid.

Testosterone and erection medicines

None of the six US and EU GLP-1 labels reviewed mention testosterone; if you use it, tell your doctor, and leave any change to whoever prescribes it. For erection medicines, neither the GLP-1 labels nor the tadalafil label describe an interaction, but nitrates with them are not allowed, and low fluid volume can affect their safety alongside alpha-blockers.

Before surgery or sedation

Tell the team before any surgery, endoscopy, colonoscopy or sedation. The labels note a rare risk of stomach contents being breathed in under anesthesia, and the EU product information asks teams to consider this before general anesthesia or deep sedation.

For today: list every medicine and supplement you take in Hombrio's questions and show the list to your doctor or pharmacist. Never stop or change a medicine on your own because of this page.

To take to your appointment

• Here is everything I take. Does anything need extra attention with this medicine?
• Do any of my tablets need to be timed differently?