antifungals

Question 1

name common antifungals

Answer 1

nystatin
clotrimazole
fluconazole

Question 2

antifungals MOA

Answer 2

ergosterol is like choelsterol for fungi

• polyene antifungals e.g. nystatin bind to ergosterol in cell membrane = causing intracellula ions to leak out of cell
  can kill or slow growth
• ergosterol synthesis inhibitors = imidazole and triazole aka clotrimazole. = stop cell membrane, growth and replication

Question 3

SE antifungals

Answer 3

nystatin and clotrimazole = topical use at site. SE = local irritation

fluconazole = oral = GI upset, headache, hepatitis and hyeprsensitivity = skin rash

rare = severe hepatoxicity, prolonged QT, cutaneous reactions and anaphylaxis

Question 4

CI antifungals

Answer 4

• nystatin and clotrimazole = no major CI as topical

fluconazole - careful dose in liver disease and renal impairment.
also TERATOGENIC

Question 5

antifungals Interactions

Answer 5

• Topical = n/a
• fluconazole inhibits cyp450 enzymes so co prescription with other cyp 450 reliant enzymes needs to be considered.
• reduces clopidogrel effect which needs liver metabolism
• increased arrythmias in patients with other drugs prolonging QT-i

Question 6

nystatin topical dose for oral thrush

Answer 6

100,000 units QDS 7 days or till 48hrs after resolved.

Question 7

what do we use clotrimazole for

Answer 7

• ringworm and tinea. fungal infections of skin and genital tract. also for candida.

Question 8

dose of clotrimazole for skin/mucosal infections

Answer 8

1% cream BD/TDS until 1-2 weeks after infection has resolved . also availabke as pessary for thrush in vagina

Question 9

oral fluconazole dose for vaginal candidiasis

Answer 9

150mg single dose.

Question 10

oral fluconazole dose for mucosal infections excluding vagunal

Answer 10

50mg OD 1-2 weeks

longer for fungal ksin infections. also available IV

Question 11

how should patients take nystatin for oral thrush

Answer 11

• after food and held in mouth to allow contact of lesion. (remove dentures)