Subcutaneous Calcitonin in Acute Herpes Zoster

Herpes zoster is associated with inflammation of the dorsal root ganglion and peripheral nerves, and this inflammation is considered to be an important causative factor for postherpetic neuralgia.

Interventions aimed at reducing this inflammation should therefore be effective in decreasing the likelihood of developing postherpetic neuralgia. Epidural administration of corticosteroids and local anesthetics has been shown to be effective, but is associated with the risk of arachnoiditis. Subcutaneous injection in an outpatient setting may be effective in preventing postherpetic neuralgia and is also considerably safer. Calcitonin has previously been shown to be effective in the management of acute pain following amputation. Also it was used in a previous study to prevent complex regional pain syndrome in severe hemiplegic patients after stroke. Also, a previous case report revealed that IV calcitonin provided immediate and sustained improvement in post herpetic neuralgia for over two months, without adverse effects from the calcitonin therapy.

However, no previous trials evaluated the effect of subcutaneous calcitonin as a preventive measure against the development of postherpetic neuralgia. We will conduct this study as we hypothesize that calcitonin therapy in patients with acute herpes zoster may be associated with better acute pain control and therefore may decrease the incidence of postherpetic neuralgia.

Inclusion criteria

• patients aged ≥ 50 years, with acute herpes zoster infection (rash duration < 7 days) and moderate to severe pain.

Exclusion criteria

• Coagulation abnormalities
• Pre-existing other pain syndrome or psychological disorders.
• Severe hepatic, cardiovascular, or renal disorders.
• Allergy to calcitonin.