💊 Metformin – Information for Older Adults
Plain-language information about metformin in older adults. This page is for older Canadians and their caregivers. It does not replace advice from your own health-care provider.
Metformin
Diabetes Medication (Biguanide)
1. What is metformin used for?
Metformin is a medication most commonly used to treat type 2 diabetes. It helps lower blood sugar levels.
Metformin can be used on its own or together with other diabetes medications or insulin. It is usually taken by mouth as a tablet.
💡 Good to know
Metformin is often the first medication doctors try for type 2 diabetes because it has been used safely for many years and rarely causes low blood sugar on its own.
2. How does metformin usually help?
Metformin works mainly by:
Helps your body use insulin more effectively
Lowers the amount of sugar made by your liver
This can help lower blood sugar and may reduce the risk of some diabetes complications when used as part of an overall treatment plan (food, activity, and other medications if needed).
3. Why metformin needs extra care in older adults
Older adults taking metformin may have:
- Changes in kidney function
- Other medical conditions (such as heart or liver problems)
- Several other medications at the same time
👨⚕️ Because of this, health-care providers often:
4. How metformin is usually taken
⚠️ Important
Follow the exact instructions from your doctor or nurse practitioner. Do not change your dose on your own.
In general:
Usually taken with meals to reduce stomach upset
Some take it once a day (often with evening meal), others twice daily
Long-acting forms may be taken once daily
❓ If you miss a dose
Follow the instructions given by your health-care provider or pharmacist. Do not double up unless they tell you to.
5. Possible side effects older adults may notice
Not everyone has side effects. Common ones can include:
Especially when starting or when dose is increased
May decrease over time
Some people notice a metallic taste in the mouth
💡 Good news
These side effects often improve over time for many people. Taking metformin with food can help. Tell your provider if side effects are severe or do not go away.
⚠️ Rare but serious
Rare but more serious side effects can happen, especially if kidney function is poor or during serious illness. Your provider will decide whether metformin is safe for you and when it should be paused.
6. When to be extra careful with metformin
Older adults taking metformin should talk with their health-care provider about what to do if they:
⚠️ Temporary stop
In some of these situations, your provider may tell you to temporarily stop metformin and then restart it later. Do not decide this on your own.
7. Habits and lifestyle that may help
Metformin works best as part of an overall diabetes care plan. In general, providers often recommend:
Regular meals and snacks (if advised), rather than skipping and then overeating
Include vegetables and high-fibre foods more often
Stay as active as is safely possible (short walks, simple exercises), with provider approval
Check blood sugar as instructed and bring records to appointments
✅ Always ask first
Always ask your doctor, nurse practitioner, or dietitian what food and activity changes are safe and realistic for you. Do not make major changes without checking first.
8. When to call your doctor, nurse practitioner, or pharmacist
(Non-urgent)
Contact your health-care provider or pharmacist if:
- You have ongoing stomach upset, nausea, or diarrhea that does not improve
- You are losing weight without trying, or have poor appetite
- Your blood sugars are often much higher or lower than the targets you were given
- You are starting a new prescription or over-the-counter medicine and are not sure if it is safe with metformin
- You have questions about how to take metformin with your other diabetes medications
9. When to call 911 or go to the emergency department
🚨 Call 911 immediately if:
- You are extremely weak, confused, or cannot stay awake
- You have trouble breathing
- You have chest pain or pressure that does not go away
- You feel very unwell with high blood sugars, heavy breathing, stomach pain, or vomiting, and cannot reach your health-care provider
If possible, do not drive yourself. Ask someone to call for you or call an ambulance.
10. Questions to ask your doctor or nurse practitioner
You can print these questions and bring them to your next appointment:
⚠️ Important Disclaimer
The information on SeniorHealthGuide.ca is general and may not fit your exact situation. It is for education only.
It does not replace medical advice, diagnosis, or treatment. Only a health professional who knows your medical history can tell you what is right for you.
Never start, stop, or change any medication, or make major changes to your diet or exercise, without checking with your doctor, nurse practitioner, or pharmacist.