What is the management approach for a 72-year-old female with Diabetes Mellitus (DM) and Coronary Heart Disease (CHD) experiencing increasing neuropathic pain and Impaired Renal Function (previously documented Glomerular Filtration Rate (GFR) of 50)?

From the Guidelines

For a 72-year-old patient with diabetes mellitus, coronary heart disease, increasing neuropathic pain, and moderate renal impairment (GFR 50), I recommend starting with gabapentin at a reduced dose of 100mg at bedtime, gradually titrating up to 300mg three times daily as tolerated. Due to the reduced kidney function, dosing should be adjusted and carefully monitored 1. Alternatively, pregabalin could be used starting at 75mg twice daily, adjusted based on response and tolerability 1. For patients who cannot tolerate or don't respond to these medications, duloxetine 30mg daily (increased to 60mg if needed) is another option, though it requires careful monitoring with renal impairment 1. Non-pharmacological approaches should be implemented concurrently, including:

• Tight glycemic control to prevent further nerve damage
• Regular foot examinations
• Physical therapy Topical treatments like capsaicin cream or lidocaine patches may provide localized relief with minimal systemic effects 1. The patient's renal function should be monitored regularly, as diabetic neuropathy and nephropathy often progress together 1. These recommendations aim to balance pain relief with the need to avoid medication toxicity in the setting of reduced renal clearance and multiple comorbidities. Key considerations in managing this patient include:
• Monitoring for potential adverse effects of medications, particularly in the context of renal impairment and coronary heart disease
• Regular assessment of pain and adjustment of treatment as needed
• Emphasis on non-pharmacological interventions to improve overall quality of life and reduce the risk of further complications.

From the FDA Drug Label

2.1 Important Administration Instructions Pregabalin is given orally with or without food. When discontinuing pregabalin, taper gradually over a minimum of 1 week [see WARNINGS AND PRECAUTIONS (5. 6)]. Because pregabalin is eliminated primarily by renal excretion, adjust the dose in adult patients with reduced renal function [see DOSAGE AND ADMINISTRATION (2.7)].

2.2 Neuropathic Pain Associated with Diabetic Peripheral Neuropathy in Adults The maximum recommended dose of pregabalin is 100 mg three times a day (300 mg/day) in patients with creatinine clearance of at least 60 mL/min.

The management approach for a 72-year-old female with Diabetes Mellitus (DM) and Coronary Heart Disease (CHD) experiencing increasing neuropathic pain and Impaired Renal Function (previously documented Glomerular Filtration Rate (GFR) of 50) would involve dose adjustment of pregabalin due to reduced renal function.

• The patient's GFR is 50, which is less than 60 mL/min, so the maximum recommended dose of pregabalin may need to be reduced.
• The dose adjustment for patients with reduced renal function is described in section 2.7 of the dosage and administration instructions, but the exact adjustment for a GFR of 50 is not provided in the given text.
• It is recommended to consult the full prescribing information for guidance on dose adjustment in patients with impaired renal function 2.

From the Research

Management Approach for Diabetic Peripheral Neuropathic Pain

• The patient's diabetic peripheral neuropathic pain can be managed with first-line pharmacologic therapy, including gabapentinoids (pregabalin and gabapentin) and duloxetine 3.
• Duloxetine is a serotonin and norepinephrine reuptake inhibitor (SNRI) proven safe, effective, and cost-saving in reducing diabetic peripheral neuropathic pain symptoms at a dose of 60 mg/day 4.
• However, duloxetine use should be avoided in patients with severe renal impairment, and the patient's previously documented Glomerular Filtration Rate (GFR) of 50 should be considered when determining the appropriate dosing regimen 4, 5.

Considerations for Renal Impairment

• When managing drug therapy in patients with renal impairment, an equally effective drug that can be used more safely should be considered before starting a renally excreted drug 5.
• The reliability of the estimated glomerular filtration rate (eGFR) should be assessed, and a gradual drug dose adaptation according to the renal function may be necessary 5.
• Monitoring effectiveness and adverse drug reactions is important, especially for drugs with a narrow therapeutic window, and dose adjustment should be based on an ongoing assessment of clinical status and risk versus the benefit of the used regimen 5.

Comparison of Duloxetine and Pregabalin

• Pregabalin has a better safety profile and tolerability compared to duloxetine, but duloxetine is more effective in treating diabetic peripheral neuropathic pain 6.
• The choice between duloxetine and pregabalin should be based on the individual patient's needs and medical history, considering the potential side effects and effectiveness of each medication 6.