Itraconazole

Indications include: (1)

• vulvovaginal candidiasis
• pityriasis versicolor
• onychomycosis

Cautions include:

• pregnancy and breast feeding
• avoid if history of liver disease
• beware interactions - See current issue of BNF
• contraindicated for the treatment of onychomycosis in patients with evidence of ventricular dysfunction (2)

Side-effects include:

• nausea
• abdominal pain
• dyspepsia
• headache
• heart failure - between September 1992 and April 2001, the Food and Drug Administration in the US received reports of 58 potential cases of congestive heart failure with itraconazole. The underlying mechanism of the itraconazole's negative ionotropic effect is unknown (2)

Notes (3):

• heart failure and itraconazole
  • the mechanism of congestive heart failure due to itraconazole is undetermined
    • it has been shown in animal models that itraconazole decreased cardiac contractility, which indicated a direct negative inotropic effect upon the heart
    • it is uncertain whether the heart damage is reversible
    • they also showed that itraconazole decreased heart rate and coronary flow and prolongation of PR and QRS intervals.

The summary of product characteristics should be consulted before prescribing this drug.

References:

1. British National Formulary (BNF); Itraconazole. NICE Evidence Services (UK access only)
2. Lancet 2001;357 (9270): 1766-67.
3. Qu Y, Fang M, Gao B, Amouzadeh HR, Li N, Narayanan P, et al. Itraconazole decreases left ventricular contractility in isolated rabbit heart: Mechanism of action. Toxicol Appl Pharmacol. 2013;268:113-22