Page 137 - BSAVA Guide to Pain Management in Small Animal Practice

BSAVA Guide to Pain Management in Small Animal Practice

VetBooks.ir Author’s perspective continued

4. Identify and treat relevant co morbidities if indicated e.g. renal, hepatic, cardiac or
musculoskeletal disease . reatment may need to be ad usted accordingly.
. iscuss treatment plan and expectations with the client.
2
ild to moderate neuropathic pain may respond to non-steroidal anti-in ammatory drugs
s alone or in a com ination with ga apentin. hronic or severe neuropathic pain often
re uires multimodal analgesia.
■ Initiate therapy of the disease causing neuropathic pain if applicable.
■ Pharmacological treatment for neuropathic pain: oral medication
•
– Non steroidal anti in ammatory drugs. Cyclo oxygenase inhibition caused by NSAI s
treats associated in ammatory components and has been shown to help alleviate
neuropathic pain
– Corticosteroid therapy. ay be preferred depending on the underlying disease
process. Corticosteroids have an anti in ammatory e ect as well as an e ect on
sympathetically mediated pain by decreased substance P expression.
• Calcium-channel blockers:
– abapentin. here is a wide dose range for gabapentin; it should be given to e ect.
Reported to take up to weeks for full e ect, although the author commonly notices a
response within a few days. apering of the dose is important to avoid possible
rebound pain. ogs start at 1 mg kg 8 1 h, then increase incrementally up to 6
mg kg orally, divided 8 1 h. Cats 1 mg kg orally 8 1 h
– Pregabalin. Appears to be more e ective in some dogs.
• Opioids. pioid receptors in the descending pathway may be reduced or inactivated in
neuropathic pain; therefore, their e cacy is fre uently inade uate when used alone. ay
be used for treatment of acute pain or breakthrough pain. Sedative e ect commonly limits
neurological assessment and thus, if possible, opioids should be avoided prior to
assessment. Urinary retention is reported as a side e ect of long term opioid use.
– entanyl transdermal patch or solution . Used only in exceptional circumstances due
to long duration of action.
• N -aspartate receptor (NMDA) antagonists:
– Amantadine. Can help to break a chronic pain cycle. ay be bene cial in severe
traumatic brain in ury.
•
– Amitriptyline. Blocks the reuptake of catecholamines, thereby enhancing adrenergic
transmission. Serves as an N A receptor antagonist.
■ Pharmacological treatment for neuropathic pain: injectable medication
• Methadone. Possibly better for treating neuropathic pain than tramadol. In addition to its
opioid analgesic properties it is also an N A receptor antagonist and serotonin reuptake
inhibitor SRI .
• Ketamine continuous rate infusion (CRI). etamine does not directly dilate cerebral
vessels. It did not have an adverse e ect on cerebral haemodynamics in patients with
head trauma athews, 8 . etamine may reduce an increasing intracranial pressure
ICP in patients with an already increased ICP if combined with a ben odia epine. Its
analgesic e ect is via N A receptor antagonism.

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