Management of Painful Diabetic Peripheral Neuropathy

Diabetic peripheral neuropathy (DPN) is one of the commonest complications of type 2 diabetes and may be present at time of diagnosis.

Diabetes can affect all nerves and so diabetic neuropathies are heterogenous with diverse clinical manifestations. They may also be focal or diffuse, the most common diffuse neuropathy is the chronic sensorimotor neuropathy (“glove and stocking”) diabetic peripheral neuropathy and the most common focal neuropathy is carpal tunnel syndrome (median nerve compression).

Prevalence

DPN may be present at time of diagnosis in over 10% of patients and may affect up to 50% of patients with long standing diabetes. In 50% of diabetic peripheral neuropathy may be asymptomatic but in 16% to 26% of patients with diabetes the neuropathy is painful.

Clinical Monitoring

Patients should be examined for DPN from time of diagnosis and their feet should be examined at each clinic visit for signs of peripheral neuropathy using a 10g monofilament and vibration perception (128 Hz tuning fork) – refer to national model of footcare

Diagnosis

The diagnosis of DPN is a diagnosis of exclusion but complex investigations are rarely needed to exclude other conditions. Consider however other causes including alcohol excess, B12 deficiency (patients on metformin), underlying vasculitis, inherited neuropathies, neurotoxic medications and chronic inflammatory demyelinating polyneuropathy.

Treatment

  • The first step is to aim for stable and optimal glucose control
  • Refer to National Model of Footcare for care of the “at risk” foot

Medication type/classifications / Advantages of this medication / Potential side effects and/or notes of caution when choosing this medication
First line therapy - Pregabalin
Start at low dose of 25mg and increase by 25mg 2-weekly to 75mg dose.
Increase dose further according to
patient response to 75mg bd with upward titration to the effective dose.
The maximum tolerated dose is 300mg bd. / Symptom relief
Improve well being
Reduce anxiety
Reduce pain / Drowsy
Dry mouth
Fatigue
Dizziness
Visual disturbance
Impaired memory
AVOID ABRUPT WITHDRAWAL (taper dose over at least 1 to 2 weeks)
First line therapy – Amitryptiline
Anti-cholinergic
Start at low dose of 10mg daily, given at night, and increase gradually according to pain response to max dose of 75mg daily. / Relieve pain
Improve sleep pattern
Improve well being / Dry mouth
Urinary retention
Drowsy
Hyponatraemia
Fatigue
Mydriasis
First line therapy – Duloxetine
SNRI
Start at 60mg dose (in elderly patients start at 30mg).
Increase dose according to pain response to maximum of 120mg daily / Relieve pain
Improve sleep pattern
Improve well being
Reduce anxiety / Nausea, vomiting
Constipation
Diarrhoea
Weight changes
Dry mouth
Sweating
AVOID ABRUPT WITHDRAWAL (taper dose down over at least 1 to 2 weeks)
Second line therapy – combination of the above treatments – see algorithm
Third Line Therapy – ask for specialist advice, refer to consultant endocrinologist/diabetes service

Recommended Care Pathway for the management of painful peripheral Neuropathy


Suggested areas for auditing this process in line with the principle of continuous improvement in the services delivered to patients with Type 2 Diabetes:

  • Frequency of checking a patient for Diabetic Peripheral Neuropathy (DPN)
  • Number of patients on oral treatment for Diabetic Peripheral Neuropathy (DPN) who have responded to treatment .
  • Number of patients with Diabetic Peripheral Neuropathy (DPN) referred to Diabetes Service for further treatment
  • Prevalence of diabetic peripheral neuropathy
  • Choice of and response to treatment