Table 4 Effect on pain and quality-of-life of agents used to treat herpes zoster (HZ) and/or post-herpetic neuralgia (PHN)

Antiviral agents

Relieve acute HZ pain and accelerate lesion healing if administered within 72 h of acute-symptom onset [8].

Few adverse effects [75, 76].

May slightly reduce PHN symptoms and their duration [5, 8, 60, 67, 71, 77–79].

Administration within 72 h is usually not achievable [8].

In clinical trials, 20%-30% of treated patients still develop PHN [37, 71].

Corticosteroids

Reduce intensity of pain and overall duration of the acute phase [37, 80, 81].

Significantly accelerate time to uninterrupted sleep, return to daily activity, and cessation of analgesic therapy.

Do not prevent PHN and produce significant adverse events in older adults; their routine use is therefore not recommended in elderly patients with HZ [37].

Simple analgesics

May reduce pain in HZ and PHN [11, 75].

Few trials assessing efficacy in HZ or PHN.

Tricyclic antidepressants

Provide effective pain relief in PHN patients (numbers needed to treat = 2.8) and may possibly provide benefits through sedative actions given that PHN can induce sleep disturbances and anxiety [67].

Side-effects may cause further QoL problems.

Patients do not regain the level of life-satisfaction that they had before PHN developed [43, 67].

Antiepileptics

Gabapentin and pregabalin offer reasonable relief for PHN [82–84].

Levels of pain relief are not associated with similar improvements in QoL scores [82–84].

Opioids

Maximum tolerable doses may reduce PHN pain [67].

Side-effects are common and troublesome, particularly for elderly patients; overall benefits are therefore limited [67].

Topical agents

Lidocaine patch provides some pain relief and has few side-effects [85].

Capsaicin dermal patch significantly reduces pain [86].

Discomfort experienced with capsaicin formulations; overall benefits are therefore limited [11].

Pain relief with capsaicin dermal patch is not associated with improved QoL in PHN [86].

Epidural therapies and nerve blocks

Continuous epidural local anaesthetic has been shown to effectively treat acute-phase HZ pain [87].

Prolonged (not single-dose or short-term) epidural local anaesthetic blockade with corticosteroid may provide some protection against PHN [88].

Single-dose epidural local anaesthetic/steroid does not prevent PHN [89].

Epidural corticosteroid has potential risk, and anecdotal evidence has not supported the benefit.

Prolonged epidural local anaesthetic blockade is not practical for widespread use and carries some risk [88].