Topical and IL chemotherapeutics

shevyatiwari's version from 2015-04-22 02:40


Question Answer
A structural analogue of fluorineF. Analog of uracil with a fluorine atom at C-5
Application to diseased skin results in 20% greater systemic absorption than to normal skinF. Is 15-75 times greater than normal skin
Systemic absorption is <5% T. 1-6% roughly
5-FU undergoes metabolism intracellularlyT
5FU has inactive metabolitesF. Active - fluorodeoxyuridine monophosphate, triphosphate and fluorouridine triophosphate
The important enzyme is DHFUF. DPD (didhydropyrimidine dehyrogenase), converts 5-FU to Dihydrofluorouracil
5-FU is catabolised in the liverT, 80%, to CO2 and excreted by the lungs, remainder in urine
5-FU is an alkylating agentF. Antimetabolite
5-FU is misincorporated into RNAT
5-FU blocks thymidylate synthetaseT, interferes with DNA synthesis
5-FU is more selective for AK than normal skinT
DPD deficiency and allergy is a C/I to 5-FUT
5-FU is category DF, category X
5-FU should not be given to women who are, or are planning to become pregnnatT
The most common adverse effects are erythema, irritation, burning, pain, pruritis, hypopigmentation and hyperpigmentationT
Adverse effects generally start after 5-10 days of treatmetnT
Allergic contact dermatitis is possible with 5-FUT
Systemic adverse effects are seen in approx 15%F. Rare
Treatment periods are longer for SCC in situ compared to BCCF. SCC in situ 8 weeks, BCC > 11 weeks
Hands should be washed post applicationT
Topical corticosteroids can be used concomitantly with topical 5-FU and for 1-2 weeks after to relieve inflammation however this can compromise efficacyF, doesn't impact efficacy

Methclorethamine/Nitrogen Mustard

Question Answer
Nitrogen mustards are a group of antimetabolites with broad applications in cancer treatmentF, alkylating agents
Low reactivity with DNAF, highly reactive
Donate alkyl groups to DNA and thus disrupt normal cell functionT
Used for MFT
There is significant systemic absorption from topical NMF, no systemic absorption, no systemic toxicities reported
Weak electrophileF, strong
Chemically unstable, resulting in the formation of covalent linkages by alkylation of nucleophilic moietiesT
The ointment is more efficacious than aqueousF, both are efficacious. Ointment was available later
Hypersensitivity, numerous SCC's and treatment with skin damaging therapy such as radiation are all C/IF. Hypersensitivity is. SCC's and radiation are not - should have caution in these patients
The most common A/E is irritant or allergic CDT
ICD occurs in 25% and is worse if used on skin foldsT
ACD is more common with the ointment cf aqueousF, more common with aqueous
CD can be managed by reducing frequency, strength, concurrent administration with TCS, formal desensitisationT
There is increased risk of secondary cutaneous malignancyT
Post inflammatory hyper or hypo pigmentation is a potential S/ET
Can be safely applied to genital skinF
Solution must be prepared daily due to instability in waterT
Ointment prepared by dissolving in alcohol and then an anhydrous ointment baseT
Ointment can last 1-3 monthsT
Should be applied thickly to the skin dailyF, thinly
Hands should be washed after applicationT
Test area application is application to the same area for 48 hoursF, 7-10 days


Question Answer
Nitrosurea compoundT
Mechanism of action is alkylationT
Used topically for MFT
Undergoes spontaneous enzymatic degradation to form strong electrophiles that alkylate DNAF, non enzymatic
Erythema stimulating a sunburn is an uncommon S/EF, common
Skin tenderness is a sign of a severe reaction and can persist months laterT
Telangiectasis are present in mild reactionsF, severe reactions often followed months later by telangectasias which lasted months-11 years
Leukopenia is a common S/EF, <4%
Allergy occurred in <10%T, limited to the skin
Risk of secondary cutaneous malignancyF
Ointment is less effective than aqueous and causes milder reactionsT
Hypersensitivity and use in children is C/IF, in children it should be used with caution
Erythema is least in the body folds, axillae, groinF, worst here
Moderate-severe erythema, pruritis warrant dose reductionF, stop
Telangectasias can be pre-malignantF
Systemic adverse effects include BM suppressionT. Mild anaemia noted, thrombocytopenia NOT noted
UEC frequently affectedF, should not be affected
FBP pre treatment and monthlyT
Stable in the fridge for 3 monthsT
Dissolved in tap water then ethanolF, other way around
Should be applied by handsF, by a nylon brush. Wear plastic/latex gloves
Ointment prepared by mixing alcoholic solution with white petrolatumT
40mg ointment can be used for 20% BSAF, shouldn't be used to treat >10% BSA due to hazard of BM suppression


Question Answer
IL for KST
Cell cycle specificT
Binds to tubulin and potentiates its activity to polymerise into microtubules leading to arrest of cell division in metaphaseF, blocks its ability
Can induce DC maturationT
Beneficial to use lignocaineF
Beneficial to use hyaluronidaseT


Question Answer
A vinca alkaloid that disrupts micro tubular functionT
Used for KST


Question Answer
Fermentation product of Streptococcus verticillusT
Causes oxidative damage to deoxyribose backbone of DNA chain -> single and double stranded breaksT
Erythema, burning, pain, swelling are commonT
Pain is the most frequent S/ET
Persistent Raynaud's, anaphylaxis, flagellate hyperpigemntation are commonF. More common with IV
Nail dystrophy or loss is a S/E for periungal wartsT
Injections every 3-6 weeksT, unless for vascular abnormalities 2-4 week of lower concentration

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