Eligibility Criteria

Subject population

Adults ≥50 years with a clinical diagnosis of herpes zoster presenting <144 hours of rash onset.

Inclusion criteria

Adults ≥50 years, with a clinical diagnosis of HZ, rash onset <144 hours

Exclusion criteria

There are limited data available to quantify terms such as prolonged, recent, significant or severe; so it is within the prescriber’s clinical judgement

  1. Third or more episode of herpes zoster
  2. Known adverse reaction to amitriptyline or contraindications (monoamine oxidase inhibitors)
  3. Current/recent (within previous two weeks) use of a tricyclic antidepressant
  4. Prolonged Q-T interval or concomitant drugs that prolong the QT interval
  5. Suicidal ideation
  6. Heart block
  7. Recent (within 4 weeks) myocardial infarction
  8. Immunosuppressiona
  9. Significant bradycardia
  10. Uncompensated heart failure
  11. Hyperthyroidism
  12. Severe liver disease
  13. Phaeochromocytoma
  14. Urinary retention
  15. If female, current or planned (in the next 3 months) pregnancy or breast-feeding
  16. Currently (or recently, within the previous 4 months) enrolled in another CTIMP
  17.  Inability to provide informed consent and complete study assessments/questionnaires

a Immunosuppression defined as:

Due to disease or treatment, including:

        • patients undergoing chemotherapy leading to immunosuppression
        • patients undergoing radical radiotherapy
        • recipient of solid organ, bone marrow or stem cell transplants
        • HIV infection
        • haematological malignancy, including leukaemia, lymphoma, and myeloma
        • genetic disorders affecting the immune system (e.g. IRAK-4, NEMO, complement disorder, SCID).

Individuals receiving immunosuppressive or immunomodulating biological therapy, including:

        • anti-TNF, alemtuzumab, ofatumumab, rituximab
        • protein kinase inhibitors or PARP inhibitors
        • sparing agents such as cyclophosphamide and mycophenolate mofetil
        • systemic steroids for more than a month at a dose equivalent to prednisolone at 20mg or more per day for adults.