Antifungals

Fungal infections major surgical problem
- mostly Candida

At Risk:
- organ tx
- multiple abdo operations
- parental nutrition
- prolonged icu stay (>7d)
- candida colonization.

Species
9 Candida sp. are potentially pathogenic
- esp albicans (generally fluconazole susceptible), also glabrata (tx pts); tropicalis, others.
 
Pathophysiology
Fungal infxs generally arise at four sites
- urinary catheters, IV lines (and peritoneal dialysis catheters), normally sterile uninfected location colonization and GI tract
Colonization is a key risk factor for invasive infection
- and absence of colonization makes infection unlikely

Clinical Features
Candidaemia is a high mortality disease
- blood cultures only 50% sensitive and take several days to turn positive
- remove all catheters and search for source; early appropriate treatment improves survival
- continue treatment until >10d since last positive culture
Abdominal infections
- typically after prolonged course/s of abx
- fluconazole is agent of choice unless resistance known or suspected
- beware peritoneal dialysis catheters; often low grade fevers, malaise, turbid abdo fluid; remove catheter and fluconazole
Urinary tract
- distinction b/n colonization and infection here is unclear
- us. prolonged catheterization, DM or incomplete emptying
- use oral fluconazole, particularly after catheter removal
Oral tract
- oral ketaconazole or fluconazole
Immunosuppressed
- aspergillosis is a devastating i.d.
- can be invasive pulmonary disease

Prophylaxis?
no demonstrated role;
however, identifying and treating colonization to help minimize progression

Antifungals

1. Triazoles
- fluconazole most common
- inhibit cp450 in fungi so drug interactions common; e.g. warfarin
- emerging resistance
- itraconazole commonly for esophageal and Aspergillosis

2. Others
- Echinocandins
- Polyenes; e.g. amphotericin B;
 - Azoles; e.g. clotrimazole