A 66-year-old man with a 10-year history of type 2 diabetes mellitus comes to the office due to burning and stabbing pain in his feet for the past few months. The pain is severe enough to interfere with his daily activities and is worse at night. His medical history is notable for hypertension, hyperlipidemia, and coronary artery disease with a non-ST elevation myocardial infarction 4 years ago. The patient is on a mixed regimen of insulin glargine and insulin aspart, in addition to other medications, including metoprolol, valsartan, atorvastatin, and aspirin. On physical examination, there is loss of ankle reflexes bilaterally, with loss of vibratory sensation and altered proprioception below the knees. Hemoglobin A1c is 8.6% and serum creatinine is 1.55 mg/dL. In addition to optimizing glycemic control, which of the following is the most appropriate medication for management of this patient's current symptoms?

Question

A 66-year-old man with a 10-year history of type 2 diabetes mellitus comes to the office due to burning and stabbing pain in his feet for the past few months.  The pain is severe enough to interfere with his daily activities and is worse at night.  His medical history is notable for hypertension, hyperlipidemia, and coronary artery disease with a non-ST elevation myocardial infarction 4 years ago.  The patient is on a mixed regimen of insulin glargine and insulin aspart, in addition to other medications, including metoprolol, valsartan, atorvastatin, and aspirin.  On physical examination, there is loss of ankle reflexes bilaterally, with loss of vibratory sensation and altered proprioception below the knees.  Hemoglobin A1c is 8.6% and serum creatinine is 1.55 mg/dL.  In addition to optimizing glycemic control, which of the following is the most appropriate medication for management of this patient's current symptoms?

Quizplus · Accepted Answer

11ec25c8_d3ac_1635_bc81_2b5850e86f21_MD0003_00 This patient with uncontrolled diabetes mellitus (elevated hemoglobin A1c) has neuropathic pain and symmetric distal neurologic deficits (eg, loss of reflexes, altered vibration and proprioception) consistent with sensorimotor polyneuropathy due to diabetes mellitus. The clinical features of diabetic neuropathy depend on the type of nerve fibers involved; small fiber neuropathy predominantly causes pain, allodynia, and paresthesias, whereas large fiber involvement causes more numbness, loss of proprioception, diminished vibration sense, and loss of ankle reflexes. Both types are commonly seen together. As diabetic neuropathy progresses, the pain may diminish but the sensory deficits persist. Initial treatment options for painful diabetic neuropathy include tricyclic antidepressants (eg, amitriptyline), dual serotonin norepinephrine reuptake inhibitors (eg, duloxetine), and anticonvulsants (eg, pregabalin, gabapentin). Pregabalin is a structural analogue of gamma-aminobutyric acid and decreases pain by inhibiting the release of excitatory neurotransmitters by binding to voltage-gated calcium modulators on nerve terminals. Common side effects are drowsiness, weight gain, and fluid retention. (Choice A) Although amitriptyline is effective for reducing neuropathic pain, it should be used with caution in patients age >65 due to its anticholinergic effects, and it is not recommended in patients with pre-existing cardiac disease due to the risk of precipitating conduction abnormalities. (Choice B) NSAIDs (eg, ketorolac) are more effective for somatic (eg, joint pain) than neuropathic pain. Also, they are relatively contraindicated in patients on antiplatelet therapy for coronary artery disease and those with renal insufficiency. (Choice C) Opioids (eg, oxycodone) are possibly effective for painful diabetic neuropathy, but evidence for their effectiveness is limited, and they are not recommended as initial treatment due to the risk of abuse and dependence. (Choice D) Systemic glucocorticoids (eg, prednisone) can be used for chronic inflammatory demyelinating neuropathy, a rare disorder that can cause distal paresthesias and numbness; these patients typically have motor weakness in the upper and lower extremities. Educational objective: Initial treatment options for painful diabetic neuropathy include tricyclic antidepressants, dual serotonin norepinephrine reuptake inhibitors, and anticonvulsants. Pregabalin decreases pain by inhibiting the release of excitatory neurotransmitters. References: Evidence-based guideline: treatment of painful diabetic neuropathy: report of the American Academy of Neurology, the American Association of Neuromuscular and Electrodiagnostic Medicine, and the American Academy of Physical Medicine and Rehabilitation. (http://www.ncbi.nlm.nih.gov/pubmed/21482920)

A 66-Year-Old Man with a 10-Year History of Type 2