About the study

Shingles and post-herpetic neuralgia 

Shingles is caused by the same virus that causes chickenpox. It “sleeps” in the nerve cells for decades. When it “wakes up”, it can make people feel generally unwell, cause tingling or pain in one part of the body, followed a few days later by a rash. The rash can take up to four weeks to heal. Antiviral medicine helps reduce initial pain and rash severity. 

Some people can have “nerve pain” months after the shingles rash has gone. Called post-herpetic neuralgia, we don’t have any treatments to prevent this. Patients buy, and GPs prescribe painkillers such as paracetamol, but they often don’t help. 

Can amitriptyline prevent post-herpetic neuralgia? 

A small study published in 1997 suggested that taking a low dose (25 mg) of amitriptyline early on may help prevent post-herpetic neuralgia. We want to do a larger study to find out if using amitriptyline when the rash first appears really prevents pain later. 

The best way to find this out is by doing a clinical trial: 

  • We will recruit 846 people aged >50 years who have been diagnosed by their GP with shingles. 
  • We will ask everyone to take tablets nightly for 10 weeks: half will be given amitriptyline and the other half will get placebo (or “dummy”) tablets. 
  • We will use questionnaires to find out what happens to everyone over the following 12 months, especially whether they still have pain related to shingles at 90 days. 

All other care will be the same – this includes GPs prescribing antivirals and painkillers if needed. 

If starting amitriptyline early on does help, it is a cheap medicine that would prevent prolonged, difficult-to-treat pain for thousands of people. However, amitriptyline commonly causes side-effects such as dizziness, dry mouth and constipation. It can also cause problems when used together with some other tablets. This study is needed so we can be sure that any benefits outweigh any harms. 

Who is funding this research? 

The study is funded by NIHR Health Technology Assessment (NIHR129720). The views expressed in this publication are those of the authors and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health and Social Care (DHCS).