how does shingles occur
varicella remains dormant in dorsal root ganglion and then is reactivated and presents as shingles
transmission of shingles
cant give shingles to someone but can give someone chicken pox if they have never had it before
symptoms of shingles and the progression
starts as a painful maculopapular rash that follows a dermatome and often stops at the midline
days - weeks rash will start to crust over
pain subsides as rash heals
how long for shingles to resolve
2-4wks
when should you treat wtih antivirals
within 72hr
can be later is new lesions present
no benefit once encrusted
benefits of antiviral treatment
decrease transmission
help with pain
speed healing
prevent PHN?
antiviral regimens
valacyclovir 100mg tid
famciclovir 500tid
for 7 days
very well tolerated, equal efficacy
how should the pain be treated
analgesics scheduled
treat early
why treat pain
prevent chronic pain
decrease acute pain
improve mood and sleep
mild pain treatmetn
acetaminophen
codiene
tramadol
moderate pain treatment
oxycodone 5-15mg q4-6hr
what is post herpetic neuralgia
pain that lasts >3-4months after resolution of rash resulting for nerve damage due to inflammation form varicella
affects ADL, QOL
risk factors for PHN
old age
allodynia
severe rash or pain
prodromal pain
symptoms of PHN
rash resolved burning, stinging, throbbing allodynia (pain from something not normally painful) numbness parathesia
how long does PHN last
unknown can spontaneously resolve
mean = 3.3years
effectiveness of treatment
<50% of ppl experience more than a 50% pain reduction
why is CBT so important in PHN
it is a potentially long lasting condition that affects QOL/ADL for which there is incomplete pain relief with medication
reducing risk of PHN
vaccination
prompt, effective antiviral and acute analgesia
problems with amitriptyline
anticholinergic burden
weight gain
sedation
do not use in glaucoma, urinary retention, cardiac issues
dosing of ami and efficacy
nnt =2.6
10-25mg HS increased to 75-150mg
gabapentin AE
edema
sedation
dizziness
falls
dosing of gabapentin
100-300mg hs increase at weekly intervals up to 1800mg/day
pregabalin > gabapentin
pregab reaches target faster
once daily dosing
more reliable target dose
pregabalin AE
edema, sedation, dizziness
dry mouth
dosing and efficacy of pregabalin
nnt = 4.2
50-150mg in 2 divided doses
increase weekly by 50-150mg/day
up to 300-600mg/day
dosing and efficacy of lidocaine patch
apply tid prn
NNT=2
side effects of lidocaine
redness
issues with tramadol
NNT= 5
unknown long term efficacy
dependence, constipation, drowsiness
non pharms
pain diary cool compress exercise to improve mood CBT light loose clothing sleep hygiene
monitoring
falls
pain diary
follow up in one day for side effect
improved function
benefits of specialty compounding
can target multiple MOA
less systemic toxicity
good for localized pain
counseling for compounds
use gloves
still can get systemic AE
if too painful to apply spray is available
what is immunosenescence
general reduction in immune response as patients age
reduces vaccine efficacy
risk of shingles recurrence
6-10%
efficacy of shingrix
treat 333 people will prevent 10 shingles outbreaks and 1 PHN
dosing of shingrix
two doses 2-6month apart
advantages of shingrix
easier storage
better efficacy
non live
IM
disadvantages of shingrix
increased AE - redness, flu like feeling for 1-2days
2 doses