Simple analgesia

• These recommendations combine guidelines on the management of herpes zoster in the immunocompetent host [International Herpes Management Forum, 2002] and recommendations for the management of herpes zoster from a internationally representative panel [Dworkin et al, 2007]. CKS has also taken into account discussion in several review papers, as there is no evidence from controlled trials for paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs), codeine, or opioid analgesics for treating the pain of acute shingles [Johnson and Whitton, 2004; Dworkin et al, 2007; Schmader and Dworkin, 2008].
• Opinion differs between reviews on the approach to simple analgesia, with some recommending paracetamol and a weak opioid [Johnson and Whitton, 2004] and others suggesting paracetamol or NSAIDs [Schmader, 2007]. A UK guideline states that oral or topical NSAIDs have not been shown to be effective for post-herpetic neuralgia [BSSI, 1995], but no evidence of ineffectiveness is discussed, and it is unclear what their role is in acute shingles.

Drugs for neuropathic pain

• The recommendation to offer a trial course of amitriptyline or pregabalin (or gabapentin if there is a local decision to prefer gabapentin over pregabalin) is based on guidance issued by the National Institute for Health and Clinical Excellence on drug treatment of neuropathic pain in adults [NICE, 2010]. For further information, see the CKS topic on Neuropathic pain - drug treatment.
• Having reviewed the evidence for a number of neuropathic conditions (including post-herpetic neuralgia), the NICE guidance development group (GDG) treated the term 'neuropathic pain' as a blanket condition regardless of the underlying cause; the GDG considered this to be helpful and practical for non-specialist healthcare professionals and patients. However, condition-specific recommendations were made if robust evidence on clinical efficacy and cost-effectiveness existed (as in the case of painful diabetic neuropathy), or where the evidence was clearly uncertain and insufficient to alter current clinical practice (as in the case of trigeminal neuralgia). The GDG acknowledged that evidence for treating a particular neuropathic pain condition with a particular aetiology is often extrapolated to other neuropathic pain conditions with other aetiologies, although there is little evidence to support the validity of this [NICE, 2010].
• It is reasonable to suppose that drugs used to treat the pain of post-herpetic neuralgia may therefore have an effect in treating the acute pain of herpes zoster [Dworkin et al, 2007].

Strong opioids

• Stronger opioids (e.g. dihydrocodeine, morphine) are thought to be useful for some people [Johnson and Whitton, 2004]. The CKS recommendation to seek specialist advice regarding their use is based on extrapolated guidelines from the International Herpes Management Forum on post-herpetic neuralgia [International Herpes Management Forum, 2002]. These state that stronger opioids (e.g. oxycodone, morphine) may be considered for treatment of post-herpetic neuralgia, but they are usually used in a pain clinic.

Treatments not recommended

• CKS has not recommended the use of corticosteroids to treat acute shingles because although some evidence suggests that prednisolone may increase the rate of skin healing and relief of pain, and improve quality of life [Wood et al, 1994; Whitley et al, 1996], evidence is insufficient to confirm the effectiveness and safety of corticosteroids to prevent post-herpetic neuralgia [He et al, 2008]. There is also concern that corticosteroids may cause dissemination of herpes zoster [Wareham, 2006] and the adverse effect profile limits their use [Mounsey et al, 2005].
• Pregabalin is not recommended. It is licensed for neuropathic pain, but further post-marketing safety data are needed (black triangle) [BNF 55, 2008].