What's the next step in managing a 51-year-old male with uncontrolled type 2 diabetes mellitus (T2DM) and diabetic neuropathy, currently on Insulin Glargine (insulin glargine), Metformin (metformin), and Pregabalin (pregabalin)?

Follow-Up Management and Insulin Titration

Continue metformin 500 mg BID and increase to 1000 mg BID if tolerated, while titrating insulin glargine based on fasting blood glucose readings to achieve target FBG of 4.4-7.0 mmol/L (80-130 mg/dL). 1

Immediate Assessment at Follow-Up

At the 1-week follow-up, review the following specific parameters:

• Fasting blood glucose values from the 7-day monitoring period - identify the pattern and average FBG 2
• Hypoglycemic episodes - frequency, timing, and severity (particularly overnight) 1, 3
• Gastrointestinal symptoms - nausea, diarrhea, abdominal discomfort from metformin 1
• Neuropathic pain response - assess if pregabalin 75mg is providing adequate pain relief using a pain scale 1, 4
• Injection site reactions - lipodystrophy, skin changes, or local reactions 3
• Weight changes - insulin typically causes weight gain 1

Metformin Optimization

Increase metformin to 1000 mg BID (2000 mg total daily dose) if the patient is tolerating the current 500 mg BID without significant gastrointestinal side effects. 2, 5 Metformin should be optimized to maximum tolerated dose before intensifying other therapies, as it remains the cornerstone of type 2 diabetes management with proven cardiovascular benefits. 1

• The patient's creatinine of 83 μmol/L (approximately 0.94 mg/dL) indicates normal renal function, so no dose adjustment is needed 1
• Gradual titration by 500 mg weekly minimizes gastrointestinal side effects 1
• Continue metformin even when using insulin, as combination therapy improves glycemic control and may reduce insulin requirements 1

Insulin Glargine Titration Algorithm

Use the following structured approach based on average fasting blood glucose from the monitoring period:

If Average FBG > 10.0 mmol/L (180 mg/dL):

• Increase insulin glargine by 4 units 1

If Average FBG 8.0-10.0 mmol/L (144-180 mg/dL):

• Increase insulin glargine by 2-3 units 1

If Average FBG 7.0-8.0 mmol/L (126-144 mg/dL):

• Increase insulin glargine by 1-2 units 1

If Average FBG 4.4-7.0 mmol/L (80-126 mg/dL):

• Maintain current dose - target achieved 1

If Average FBG < 4.4 mmol/L (80 mg/dL) or hypoglycemic episodes:

• Decrease insulin glargine by 2-4 units or 10-20% of current dose 1, 3

Continue weekly follow-ups with daily FBG monitoring until stable glycemic control is achieved, then transition to follow-up every 3 months with HbA1c monitoring. 1, 2

Neuropathic Pain Management Adjustment

Given the patient's pain score of 5/10 on pregabalin 75mg OD:

Increase pregabalin to 150 mg daily (75 mg BID) if pain relief is inadequate after 1 week, with potential further titration to 300 mg daily (150 mg BID) based on response. 1, 4 The initial 75 mg dose is subtherapeutic for most patients with diabetic neuropathy. 4

• Pregabalin 600 mg/day showed significant pain reduction in clinical trials, but start with lower doses and titrate to minimize dizziness 4
• Alternative first-line agents include duloxetine or gabapentin if pregabalin is not tolerated 1, 6
• Reassess pain scores at each visit using a standardized scale 1

Critical Monitoring Parameters

Schedule follow-up visits weekly for the first month, then monthly until HbA1c target <7% is achieved. 1

At each visit, assess:

• Fasting blood glucose trends - adjust insulin accordingly 2
• Hypoglycemia frequency - particularly overnight episodes with basal insulin 1, 3
• Vitamin B12 levels - check at 3-6 months given metformin use and existing peripheral neuropathy 1
• HbA1c at 3 months - current 9.7% indicates need for aggressive management 1
• Adherence barriers - address the patient's previous fear of renal side effects with education 1

Common Pitfalls to Avoid

• Do not delay insulin titration - with HbA1c 9.7%, aggressive upward titration is necessary to prevent microvascular complications 1
• Do not stop metformin when adding insulin - combination therapy is superior to either alone 1
• Do not use fixed insulin doses - titrate based on actual glucose readings, not arbitrary schedules 1
• Do not undertitrate pregabalin - 75 mg daily is below the effective dose range for most patients 4
• Do not ignore vitamin B12 deficiency risk - particularly important in a patient with existing neuropathy on metformin 1

When to Consider Additional Agents

If HbA1c remains >7% after 3 months despite optimized metformin (2000 mg daily) and adequately titrated basal insulin (typically 0.3-0.5 units/kg), consider adding a GLP-1 receptor agonist or SGLT2 inhibitor before adding prandial insulin. 1, 2 These agents provide additional glycemic benefit with favorable effects on weight and cardiovascular outcomes. 1