GLP-1 medicines and your other prescriptions

Overview

GLP-1 agonists slow stomach emptying, which can change how quickly other tablets are absorbed. For most medicines this does not matter; for a few, particularly those used in transplantation and cardiology, it matters a great deal.

Why it's done and who it helps

• Oral Contraceptives: The change in absorption timing may reduce efficacy; we often recommend additional barrier methods during dose escalation.
• Warfarin: Closer monitoring of INR is required during the first few weeks of therapy.
• Thyroid Medication: Levothyroxine absorption can be affected; thyroid function tests may be repeated.
• Transplant Medications: As per UKKA and KDIGO 2024, cyclosporine and tacrolimus levels need careful monitoring.

Nephrology-Specific Interactions

Many patients with kidney disease take multiple medications (polypharmacy). Professor Mohammed Mahdi Althaf reviews your full prescription list to ensure no interactions with blood pressure, bone health, or anaemic medications.

Managing "Sick Days"

If you become unwell with vomiting or diarrhoea, you must follow the Renal Association "Sick Day Rules" and temporarily pause certain medications (like ACE inhibitors, ARBs, and SGLT2s) to protect your kidney function while on GLP-1 therapy.

Preparing for your appointment

Do I need to stop my other pills?

Usually not, but we may adjust the timing. Bring a full list of your medications, including over-the-counter supplements.

References

• UK Kidney Association (UKKA) Clinical Practice Guidelines
• KDIGO 2024 Clinical Practice Guideline
• NICE NG203: Chronic kidney disease: assessment and management
• British National Formulary (BNF) - GLP-1 Receptor Agonist Interactions

This article is general patient information reviewed by a consultant nephrologist. It is not individual medical advice; treatment decisions are made at a face-to-face consultation.