From the Guidelines
The most appropriate pharmacotherapy for this patient is gabapentin. This patient is presenting with symptoms of diabetic peripheral neuropathy, characterized by pain and "pins and needles" sensations in the feet, worse at night and with pressure. The physical exam findings of decreased sensation and diminished reflexes in the lower extremities support this diagnosis.
Key Points to Consider
- Gabapentin is a first-line medication for diabetic neuropathic pain as it effectively reduces pain by modulating calcium channels and decreasing excitatory neurotransmitter release in the nervous system 1.
- It's particularly beneficial because it doesn't have significant drug interactions with the patient's current medications (propranolol and insulin) and doesn't affect blood glucose control.
- Typical starting dosage is 300 mg once daily at bedtime, gradually titrated up to 300-600 mg three times daily as needed for pain control, with dose adjustments required for renal impairment.
- Side effects may include dizziness and somnolence, which can be minimized by starting at a low dose and taking it with food.
Comparison with Other Options
- Duloxetine, a selective norepinephrine and serotonin reuptake inhibitor, has shown efficacy in treating pain associated with diabetic peripheral neuropathy, but it may cause a small increase in A1C and has more severe adverse events in older people 1.
- Tapentadol, a centrally acting opioid analgesic, has been approved for the treatment of neuropathic pain associated with diabetes, but its use is not generally recommended as a first- or second-line therapy due to the high risk of addiction and safety concerns 1.
- Acetaminophen and ibuprofen are not typically used as first-line treatments for diabetic neuropathic pain, and hydrocodone is an opioid that carries a high risk of addiction and is not recommended for chronic pain management.
- Amitriptyline, a tricyclic antidepressant, may be used off-label for diabetic neuropathic pain, but it has more side effects and interactions compared to gabapentin.
Final Decision
Given the patient's symptoms and medical history, gabapentin is the most appropriate pharmacotherapy due to its efficacy, safety profile, and lack of significant drug interactions.
From the FDA Drug Label
- Clinical Studies 14. 1 Neuropathic Pain Associated with Diabetic Peripheral Neuropathy The efficacy of the maximum recommended dose of pregabalin for the management of neuropathic pain associated with diabetic peripheral neuropathy was established in three double-blind, placebo-controlled, multicenter studies with three times a day dosing, two of which studied the maximum recommended dose Patients were enrolled with either Type 1 or Type 2 diabetes mellitus and a diagnosis of painful distal symmetrical sensorimotor polyneuropathy for 1 to 5 years.
The most appropriate pharmacotherapy for this patient is not directly stated in the provided drug label. However, based on the information given, Gabapentin is often used to treat neuropathic pain associated with diabetic peripheral neuropathy, similar to Pregabalin.
- Key points:
- The patient has a history of type 1 diabetes mellitus.
- The patient is experiencing neuropathic pain.
- Pregabalin is used to treat neuropathic pain associated with diabetic peripheral neuropathy. Since Gabapentin is not mentioned in the label, but is a similar medication to Pregabalin, and Pregabalin is used for the same condition the patient is experiencing, the best choice would be Gabapentin (option C) 2.
From the Research
Patient Presentation and History
The patient presents with a 6-year history of increasing pain and a "pins and needles" sensation in their toes and feet, which is worst at night and when wearing tight shoes or socks. They have a history of type 1 diabetes mellitus and long QT syndrome, and are currently taking propranolol and using an insulin pump.
Physical Examination Findings
Physical examination reveals decreased sensation to light touch to the level of the mid-shin bilaterally, and deep tendon reflexes are 2+ in the upper extremities, 1+ at the patella, and absent at the Achilles.
Appropriate Pharmacotherapy
Based on the patient's symptoms and history, the most appropriate pharmacotherapy for their condition is:
- Gabapentin, as it is commonly used to treat neuropathic pain (pain due to nerve damage) 3
- Other options such as amitriptyline, pregabalin, and duloxetine may also be considered, as they are also recommended for the treatment of painful diabetic neuropathy 4, 5, 6, 7
Key Points to Consider
- Gabapentin has been shown to provide good levels of pain relief to some people with postherpetic neuralgia and peripheral diabetic neuropathy 3
- Amitriptyline and pregabalin have also been shown to be effective in treating painful diabetic neuropathy, with similar analgesic efficacy to gabapentin 4, 6, 7
- The choice of pharmacotherapy should be informed by patient characteristics and individual responses to treatment 5