MSK 07: Topical OTC Analgesics and Products Flashcards
1
Q
Salicylic-based Counterirritants
A
- local irritant
- increase local blood flow
- weak inhibition of COX1 and COX2 does not contribute to analgesia in muscles and joints, but may affect bleeding time due to systemic absorption
- BenGay Arthritis Cream, Salonpas Patch, Aspercreme Extra Strength
2
Q
Menthol Counterirritants
A
ADME:
- well absorbed through skin
- short t1/2
MOA:
- cooling sensation via TRPM8 (CMR1) receptor on cold fibres
- blocks neuronal Ca2+ channels for analgesia
Other:
- increase blood flow
- Ice Hot Patch, Rub A535 Ice Gel, Deep Relief Gel
3
Q
Camphor Counterirritants
A
MOA:
- TRPV1, TRPV3 and/or TRPA1 receptors for receptor desensitization (like capsaicin)
Other:
- initially cold, then warm
- increase blood flow
- Tiger Balm
4
Q
Eucalyptus Counterirritants
A
MOA:
- camphor and 1,8-cineole (TRPM8 agonist and TRPA1 antagonist)
Other:
- heating sensation
- Rub A535 Extra Strength
5
Q
Arnica Montana Counterirritants
A
MOA:
- inhibition of nuclear factor kappa-beta (NF–k𝛽) for down-regulation of COX2 and production of cytokines
Other:
- sesquiterpene lactones
- Rub A535 Arnical Gel-Cream, Arnicare Cream and Gel (homeopathic)
6
Q
Capsaicin (Capsicum-based)
A
- SIG: apply TID-QID
- MOA: desensitization of nociceptors, acts on TRPV1 receptors
- burning sensation, tingling, erythema at site of application
- delayed effect
- recommended as add-on therapy for hand/knee OA pain
- Lakota Roll-on, Zostrix Cream
7
Q
Diclofenac Diethylamine (Voltaren Emulgel)
A
SIG:
- Voltaren Emulgel Original: TID-QID
- Voltaren Emulgel Extra Strength: BID
MOA:
- penetrates skin and tissues, inhibits prostaglandin biosynthesis
- blocks peripheral NMDA receptors
8
Q
Pregnancy and Lactation
A
contraindicated in 3rd trimester – possible premature closure of ductus arteriosus and prolonged parturition
9
Q
Which topical analgesics have an odour?
A
- menthol
- camphor
- eucalyptus
