Peripheral Neuropathy Case

Question 1

Amytriptyline
Drug class
Mechanism of action
Site of action in pain pathway
Side effects
Drug interaction with warfarin?

Answer 1

• norepinephrine reuptake inhibitors
• unknown/norepinephrine reuptake
• reuptake
• weight gain, constipation, dizziness, headache, blurred vision
• increased risk of bleeding

Question 2

Pregabalin
Drug class
Mechanism of action
Site of action in pain pathway
Side effects
Drug interaction with warfarin?

Answer 2

• gaba aminobutyric acid
• reduce Ca2+ dependent GABA (and other) release
• presynaptic nociceptor
• weight gain, constipation, dizziness, headache, blurred vision
• none

Question 3

Capsaicin
Drug class
Mechanism of action
Site of action in pain pathway
Side effects
Drug interaction with warfarin?

Answer 3

• analgesic
• TRPV1 agonist, depletes substance P
• throughout
• erythema, pain, nausea
• increased bleeding risk