Background & Aims

Postherpetic neuralgia is neuropathic pain that persists 30 to 90 days after the skin outbreak disappears. It is a burning, stabbing and electrifying pain, associated with negative and positive signs: dysesthesias, paresthesias, hyperalgesia, hyperesthesia and allodynia. The incidence increases with the age of the patient, it is 10% in people over 40 years old, from 20% to 50% in people over 60 years old. Patients with advanced age, severe acute pain, and severe skin rash are risk factors for further development of postherpetic neuralgia. Treatment of postherpetic neuralgia is complex; tricyclic antidepressants, opioids and anticonvulsants are used; Medication alone does not always provide ideal efficacy, especially in patients with long-term NPH. Histological examinations of patients with NPH reveal myelin and axon deficiency. an unrestrained inflammatory response at the neuronal level is the main culprit for the eventual development of NPH.

Methods

All patients diagnosed with postherpetic neuralgia in areas of the body that were innervated by cranial or spinal nerves were included and patients refractory to one or two medication for neuropathic pain. In all of them the 0-10 scale of pain severity was administered; evaluating the presence of tingling, allodynia, burning, stabbing pain, spontaneous pain and provoked pain. We apply multimodal therapy: 1) IM administration of betamethasone 4 mg + ketorolac 30 mg + tramadol 100 mg, every 4 days for 3 times, 2) oral administration of pregabalin 75 mg twice daily + clomipramine 37.5 mg twice daily + valproic acid 250 mg twice daily + tramadol 50 mg three times a day. The assessment every 15 days of the intensity and characteristics of the pain and the presence or absence of side effects allowed the dose of the medications to be modified. A follow-up period of 3 to 6 months was carried out depending on the clinical evolution.

Results

At the first month of observation, the intensity of the pain dropped from 8 or 9 to 3 or 4 on the pain intensity scale, 22% reported the presence of two components of pain: stabbing pain + allodynia, burning + stabbing pain, stinging + burning; 25% of patients reported the persistence of a painful component, mainly burning or stinging; 96% of the patients managed to sleep without sleep interruption, side effects were minimal, with drowsiness or constipation, tramadol was discontinued; At the third month of observation, 7% reported the presence of two components of pain, 9% reported the presence of one component of pain, these percentages were maintained until the sixth month of observation, maintaining the association of clomipramine, pregabalin or acid. valproic with lower doses.

Conclusions

Multimodal pharmacological therapy, using drugs for neuropathic pain (anticonvulsants: valproic acid, pregabalin, antidepressants: clomipramine, opioids: tramadol and corticosteroids: betametazone, all of them unconventional) shows greater effectiveness in the pharmacological treatment of postherpetic neuralgia, reducing significantly the intensity of pain, reducing the complexity of pain, improving quality of life and improving sleep.

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Presenting Author

Juan Carlos Duran Quiroz

Poster Authors

Juan Carlos Duran

MD

Neurocentro

Lead Author

Topics

  • Specific Pain Conditions/Pain in Specific Populations: Neuropathic Pain - Peripheral