Page 170 Guide to Pain Management in Low-Resource Settings

158 Rainer Sabatowski and Hans J. Gerbershagen

Th ermal allodynia (pain caused by moder- • No knowledge of the use and indication of non-
ate heat or cold; a warm or cold fork or knife might be analgesic drugs (e.g., anticonvulsants) in the pres-
used) and dynamic allodynia (e.g., pain induced through ence of neuropathic pain.
contact with clothing; for the examination a cotton- From the patient’s perspective, common barri-
wool tip might be used) are distinguished. A tuning fork ers include:
can be used to look for abnormalities in the perception • No satisfactory information about the pain and
of vibration. Elaborate tests such as neurography or the drugs being used (e.g., an antidepressant was
quantitative sensory testing (QST) might be used, but prescribed, or no information was given about
often they are not available or in the case of QST, the the rationale for using opioids).
impact on diagnosis and/or treatment is not yet clear. • Fear or prior experience of side eff ects (e.g., ad-
Radiographic examination such as magnetic resonance diction, dry mouth, erectile dysfunction, and
tomography might be added in cases when further inva- drowsiness).
sive treatments are considered. • No treatment of side eff ects was provided.
• Drugs are often not available in rural sites, or the
How can pain due to plexopathy drugs being prescribed by a medical center are
in lung cancer be treated? too expensive.

Th e initial treatment approach for painful plexopathy What strategies should be followed
should follow the guidelines of the World Health Orga- when treating a painful plexopathy?
nization (WHO). However, adjuvants (e.g., anticonvul-
sants, antidepressants, and corticosteroids) are of par- Primarily cancer-reducing strategies such as chemo-
ticular importance. Th ese adjuvants are recommended therapy or radiotherapy should be considered, to reduce
at every step of the WHO ladder and sometimes might or minimize the direct impact of the tumor on the plex-
even be a fi rst-line medication before starting with non- us. However, if this approach is not possible, palliative
opioid analgesics or opioids. pharmacological strategies should be started. Palliative
treatment approaches include several pharmacological
What are barriers to eff ective and nonpharmacological options.
pain management? Anticonvulsants

From the physician’s perspective, common barriers Th ese drugs were primarily used in treating trigeminal
include: neuralgia, but current studies give evidence of effi cacy
• Lack of familiarity with diagnosing neuropathic in various neuropathic pain conditions. Carbamaze-
pain. pine acts via blockade of voltage-dependent sodium
• Reliance on nonopioid analgesics such as diclofe- channels. Th e starting dose is 100 mg twice a day up to
nac or acetaminophen (paracetamol) alone (these a maximum of 1200–1600 mg/day. Side eff ects such as
analgesics are not recommended in the algo- sedation are common, especially when the initial dose
rithms for treating neuropathic pain). is too high or titration is too rapid. Nowadays, the use
• Avoidance of opioids due to misconceptions and in cancer pain is limited due to potential risks such as
myths about opioids (e.g., fear of addiction and bone marrow suppression, leucopenia, hyponatremia,
beliefs that neuropathic pain is not responsive, and interaction with liver metabolism and therefore
that opioids should only be used for dying pa- multiple drug interactions. Gabapentin, if available,
tients, and that respiratory depression is a com- should be used as fi rst-line medication. Gabapentin is a
mon side eff ect of opioids). Th ere is evidence that chemical analogue of γ-aminobutyric acid (GABA) that
opioids do relieve neuropathic pain, and they are does not act as a GABA-receptor agonist, but binds to
included into the treatment algorithms for neuro- the α δ-subunit of the voltage-dependent calcium chan-
2
pathic pain. nel in the spinal cord. Th e binding to these receptors
• Unavailability of opioids. inhibits the release of excitatory neurotransmitters. Ga-
• Fear of legal consequences when prescribing “il- bapentin is administered three to four times a day. Th e
licit drugs.” starting dose is 3 × 100 mg, and the maximum dose