Medication (generic)
Metformin IR
Starting dose
500 mg once daily with food
Typical titration / target
Increase by 500 mg every 1-2 weeks to 1000 mg twice daily
Monitoring / notes
Hold during acute illness or dehydration.
Prescribing
Metformin start
Starting doses, titration steps, and renal considerations for metformin.
Last reviewed 2026-01-05|endocrine | diabetes | medication
Jump to
Dosing quick reference
Medication (generic)
Metformin XR
Starting dose
500 mg once daily with evening meal
Typical titration / target
Increase by 500 mg every 1-2 weeks to 2000 mg once daily
Monitoring / notes
GI side effects improve with slow titration.
| Medication (generic) | Starting dose | Typical titration / target | Monitoring / notes |
|---|---|---|---|
| Metformin IR | 500 mg once daily with food | Increase by 500 mg every 1-2 weeks to 1000 mg twice daily | Hold during acute illness or dehydration. |
| Metformin XR | 500 mg once daily with evening meal | Increase by 500 mg every 1-2 weeks to 2000 mg once daily | GI side effects improve with slow titration. |
Contraindications
- Avoid initiation if eGFR is below 30 mL/min/1.73 m2.
- Avoid when metabolic acidosis is present or suspected.
- Hold during severe intercurrent illness with dehydration, hypoxia, or unstable hemodynamics.
Renal and hepatic considerations
- Reduce dose and monitor more often when eGFR is 30-44.
- Reassess renal function promptly after acute illness or nephrotoxic exposures.
- Use extra caution in significant hepatic impairment due to lactic acidosis risk context.
Pregnancy and lactation cautions
- Review pregnancy intent and use a pregnancy-specific diabetes plan when relevant.
- Discuss potential perinatal treatment alternatives and shared decision-making before conception.
- During lactation, confirm maternal-infant monitoring expectations in the ongoing care plan.
Monitoring checkpoints
- Check renal function at baseline and at clinically appropriate intervals.
- Check B12 periodically for long-term therapy.
- Review GI tolerance and adherence after each titration step.
Stop or escalate criteria
- Stop and escalate immediately if lactic acidosis is suspected.
- Hold and reassess during acute dehydration, sepsis concern, or significant renal decline.
- Escalate treatment strategy when glycemic targets are not reached despite optimized tolerated dosing.