Introduction

Name

• Itraconazole.

Class of drug

• Triazole antifungal.

Description

Chemical name

• 2-butan-2-yl-4-[4-[4-[4-[[(2R,4S)-2-(2,4-dichlorophenyl)-2-(1,2,4-triazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]piperazin-1-yl]phenyl]-1,2,4-triazol-3-one.

Molecular formula

• C₃₅H₃₈Cl₂N₈O₄.

Molecular weight

• 705.6 g/mol.

Physical properties

• Lipophilic.

Storage requirements

• Store capsules at room temperature protected from light and moisture.
• Store oral solution at room temperature (20-25°C/68-77°F).
• Oral suspension stored in refrigerator for up to one month.

Uses

Indications

• Aspergillosis, candidiasis, blastomycosis, coccidiomycosis, cryptococcosis, cryptococcus, histoplasmosis, dermatophytoses and Malassezia.
• Used in rabbits for dermatophytosis Ringworm or less commonly, aspergillosis.

Administration

Pharmacokinetics

Precautions

Interactions

with other drugs

Antacids, H2 antagonists and adsorbents

• May reduce the absorption of itraconazole.
• In man may inhibit metabolism of antihistamines by inhibiting cytochrome P450, oral hypoglycemics, anti-epileptics, cisapride and cyclosporine.
• The significance of these interactions in veterinary species has not been studied.

Cardiovascular agents

• In humans, the class IA antiarrhythmic quinidine and class III antiarrhythmic dofetilide are known to prolong the QT interval. Co-administration of quinidine or dofetilide with itraconazole may increase plasma concentrations of quinidine or dofetilide which could result in a serious cardiovascular event.
• Concomitant administration of itraconazole and quinidine or dofetilide is contraindicated.
• The class IA antiarrhythmic disopyramide has the potential to increase the QT interval at high plasma concentrations. Caution is advised when itraconazole and disopyramide are administered concomitantly.
• Concomitant administration of digoxin and itraconazole has led to increased plasma concentrations of digoxin.
• The significance of these interactions in veterinary species has not been studied. 

Inducers of CYP3A4

• Carbamazepine, phenobarbital and phenytoin are all inducers of CYP3A4.
• Interactions with carbamazepine and phenobarbital have not been studied, however concomitant administration of itraconazole and these drugs would be expected to result in decreased plasma concentrations of itraconazole.
• The significance of these interactions in veterinary species has not been studied.

with diagnostic tests

• None known.

Adverse Reactions

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Fehr M (2015) Zoonotic potential of dermatophytosis in small mammals. J Exot Pet Med 24 (3), 308-316 SciDirect.
• Keller K A (2011) Therapeutic review: itraconazole. J Exotic Pet Med 20 (2), 156-160 SciDirect.
• Patterson T F, Fothergill A W & Rinalsi M G (1993) Efficacy of itraconazole solution in a rabbit model of invasive aspergillosis. Antimicrob Agents Chemother 37 (11), 2307-2310 PubMed.

Other sources of information

• National Center for Biotechnology Information (2022) PubChem Compound Summary for CID 55283, Itraconazole. Website: https://pubchem.ncbi.nlm.nih.gov.
• Carpenter J W (2021) Appendix: Formulary. In: Ferrets, Rabbits and Rodents Clinical Medicine and Surgery. 4^th edn. Eds: Quesenberry K E, Orcutt C J, Mans C & Carpenter J W. Elsevier, USA. pp 620-630.
• Hedley J (2020) Ed BSAVA Small Animal Formulary. Exotic Pets. 10th edn. BSAVA, UK.