Topical Anticancer Agents Flashcards
What are the indications for DCP?
Wart
Alopecia areata
Melanoma in transit
What are the contraindications to DCP?
Pregnancy
Children <10 years
Atopic dermatitis
What is the process for administering DCP?
Priming: 3 drops 2% DCP in Finn chamber to upper inner arm, leave on 48 hours and review ?sensitisation
Wart
Treatment: 0.1% DCP + 15% salicylic acid in white soft paraffin
Apply 3 times a week (with gloves & toothpick)
Wash off in AM, pare/pumice
Alopecia areata
0.001% DCP in aqueous cream
—> 0.01%
——> 0.1%
Until eczematous reaction
Wash off AM
Follow up 2 weeks
Treatment duration 1-3 months
What are the adverse effects of DCP?
Common: contact dermatitis, lymphadenopathy, blistering, skin infection
Uncommon: urticaria, EM, vitiligo/leukoderma, PIH
How do you manage generalised dermatitis/urticaria due to DCP?
Cease DCP
Empathise
Explain pathogenesis
Explore dosing/application technique
Cetirizine +- phenergan
Prednisone 0.5-1mg/kg/day tapered over 2-3 weeks
What are the indications for cantharadin?
Wart
Molluscum contagiosum
What are the contraindications to cantharadin?
Hypersensitivity
Lesion on mucous membranes
Mosaic warts
Circulatory disease eg diabetes, PVD
What are the adverse effects of cantharadin?
Pain, ICD, PIH
Annular ring wart
Cellulitis/lymphangitis
Rare: kidney or liver injury, GI haemorrhage, coagulopathy, seizure, arrhythmia, shock
What formulations does cantharadin come in?
Cantharadin (plain) 0.7%
Cantharadin plus 1%
+ podophyllin 5%
+ salicylic acid 30%
How is cantharadin applied for the treatment of warts?
Pare/shave wart
Apply cantharadin with toothpick
Apply non porous adhesive tape and leave on for 4-6hours
Remove tape and wash site
Advise patient/parent that blister forms 24-48 hours and dries up/falls off after 1 week
80% cute rate
Retreatment 1-3 weeks
How does the use of cantharadin differ between warts and molluscum contagiosum?
No occlusion
Can be combined with aldara
What is the MOA of imiquimod?
Potent TLR 7 & 8 agonist
What are the contraindications to the topical anticancer agents?
Hypersensitivity
Pregnancy/lactation
Dihydro-pyrimidine dehydrogenase deficiency (efudix)
Marked hyperkeratosis
Ulcerated/broken skin
Large lesion/treatment area
Perioroficial site
Infiltrative/recurrent/high risk lesion
Photosensitivity
Immunosuppression
Decreased haematological reserve (imiquimod)
Autoimmune disease (imiquimod)
Unreliable patient
What is the MOA of efudix?
Topical chemotherapeutic agent that selectively effects dividing cells
Acts as an antimetabolite —> blocks DNA synthesis —> prevents cell proliferation —> cell death
What is the MOA of topical diclofenac?
Unknown
?inhibits COX2 pathway leading to reduced PGE2 synthesis
What are the contraindications to topical diclofenac
Hypersensitivity
Pregnancy/lactation
Concomitant use of benzyl alcohol
Skin wound, infection, dermatitis
GI ulceration/bleeding
Cardiac/hepatic/renal impairment
What are the adverse effects of topical diclofenac?
Application site reactions eg rash, ACD, xerosis, pain, burning, pruritus
How is topical diclofenac dosed and what instructions should the patient be given about it’s use?
Apply BD for 90 days
Do not apply to broken/infected skin
Do not occlude
Avoid eyes, mouth
Photoprotect
What are the dosing regimes for efudix in
1. Actinic keratoses
2. Bowen’s disease
3. Superficial BCC
- Once to twice daily 3-4 weeks
- Twice daily for at least 6 weeks
- Twice daily for at least 6 weeks
How do you manage efudix & imiquimod local skin reactions?
- Stop efudix
- Cold compress
- Saline soaks
- Paracetamol
- Bland emollient +- wet dressings
- Microbial swab —> treat if indicated
- Advantan ointment daily for 7 days (if severe) - DO NOT use in imiquimod
What instructions should patients be given about how to apply efudix?
Consider pretreating hyperkeratotic lesions
Wash & dry skin
Apply thin film of Efudix onto lesion with non-metal applicator or glove
Avoid eyes, nares, mouth, ears
Wash hands afterwards
Apply >60mins before bed
Sun protect
Do not occlude
Advise patient it is normal for skin to become red, swollen & tender but if reaction excessive, miss dose or two
Review at 2 weeks
What are the adverse effects of efudix?
Application site reactions: pain, itch, burning, crusting, weeping, ACD, photosensitivity
Dyspigmentation, scarring, ulceration, secondary infection
Systemic: fevers, URTI sx, mouth ulcers, GI effects, lethargy, malaise
What are the adverse effects of imiquimod?
Local skin reaction: redness, oedema, irritation, flaking/scaling, crusting, ulceration, itch, burning, vesicles/bullae, Dyspigmentation
Systemic:
flu-like sx
GI effects
skin infection
flare of autoimmune disease, EM/SJS
What is the PBS criteria for treatment is superficial BCC with imiquimod?
Previously untreated
sBCC confirmed by biopsy
Not suitable for cryotherapy or C+C
Pt must have normal immune function
Pt must require topical therapy
*Date of report and pathology company must be provided
What are the dosing regimens for imiquimod in
1. Actinic keratoses
2. sBCC
3. Condyloma acuminatum/wart
4. Lentigo maligna
- 3 times per week in 4 week cycles
- Weekdays for 6 weeks
- 3 times per week for up to 16 weeks
- Weekdays for up to 12 weeks
What instructions should be given to patients about how to use imiquimod?
Wash area and dry thoroughly
Apply to lesion with 1cm margin
Rub in until no longer visible
Wash hands after application
Leave on for 8 hours and wash off mane
