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Corticosteroids
Prednisolone added to acyclovir during HZ resulted in a modest reduction in pain intensity
and improved the rate of skin lesion healing for up to 14 days, with no effect on the overall
recovery rate at 3 weeks (Wood et al, 1994 Level II). Prednisolone, either as monotherapy or in
combination with acyclovir, increased the likelihood of being ‘pain‐free’ at 1 month by a factor
of 2.3 (95% CI: 1.4 to 3.5), however there was no difference in the rate of skin healing,
compared with placebo (Whitley et al, 1996 Level II).
Anticonvulsants
Administration of a single dose of gabapentin (900 mg) during HZ reduced acute pain intensity
by 66% (33% for placebo) and also reduced the area and severity of allodynia, for up to
6 hours (Berry & Petersen, 2005 Level II), however no analgesic benefit was found when
gabapentin was administered for 28 days (Dworkin et al, 2009 Level II).
Topical lignocaine
Topical lignocaine patches (5%) applied for 12 hours twice daily (on intact skin) during HZ,
significantly reduced pain intensity and improved patient's global impression of pain relief,
compared with a control vehicle patch: the incidence and severity of adverse events was low
with both treatments (Lin et al, 2008 Level II).
Aspirin
Topical aspirin, in either moisturiser or diethyl ether, was an effective analgesic in HZ,
compared with similar preparations containing indomethacin, diclofenac or placebo
(De Benedittis et al, 1992 Level II) or oral aspirin (Balakrishnan et al, 2001 Level II).
Neuraxial or sympathetic blockade
A review of neuraxial (including sympathetic) blockade for the treatment of HZ‐associated
pain found that 71% (12/15) of studies (Kumar, Krone et al, 2004), only one of which was an
RCT (Pasqualucci et al, 2000 Level II), reported a reduction in either the incidence or severity of
HZ‐associated pain to 1 month. In a subsequent RCT, there was a significant difference in the
incidence (and to a lesser extent the intensity) of HZ pain in patients who received a single
epidural methylprednisolone and bupivacaine injection, compared with those who received
CHAPTER 9 antiviral therapy and analgesia as ‘standard care’; the NNT for complete resolution of HZ pain
at 1 month with the epidural injection was 10 (van Wijck et al, 2006 Level II). However, given the
modest clinical effects on acute pain and no effect on the incidence of PHN, the routine use of
epidural local anaesthetic and steroid injection during HZ was not supported. Evidence of
benefit for sympathetic blockade in the treatment of HZ‐associated pain was conflicting
(Kumar, Krone et al, 2004).
Prevention of postherpetic neuralgia
Immunisation of persons aged 60 years or older with live attenuated VZV vaccine, reduces
the incidence of PHN (Oxman et al, 2005) and is now recommended as the standard of care,
including for those who have experienced a previous episode of HZ (Harpaz et al, 2008).
During HZ, the early administration amitriptyline (for 90 days) (Bowsher, 1997 Level II)
significantly reduced the incidence of PHN. However, contrary to the previous literature (Wood
et al, 1996 Level I; Jackson et al, 1997 Level I; Beutner et al, 1995 Level II; Tyring et al, 2000 Level II), the
use of the antiviral agent acyclovir or famcyclovir did not significantly reduce the incidence of
PHN (Li et al, 2009 Level I).
254 Acute Pain Management: Scientific Evidence
