The Implications and Management of Drug Interactions with Itraconazole, Fluconazole and Terbinafine

The efficacy and safety of many pharmacological agents can be adversely affected by drug interactions. However, an appreciation of the mechanisms and incidence of these interactions, together with a knowledge of the patient’s medical history, means that the majority are predictable and can be managed successfully. Drug interactions involving oral antifungal agents such as itraconazole, fluconazole and terbinafine have been studied extensively and are well understood. When problems are known to arise, they can often be overcome or minimised by varying the dosage regimens, or by drug monitoring. Where certain drugs are definitely contraindicated with antifungal agents, suitable alternatives can usually be found. Clinical trials and surveillance monitoring have demonstrated that when viewed in a wider context, drug interactions do not represent a particular safety problem for the newer oral antifungal agents. An improved understanding of the drug interaction processes and appropriate control measures mean that the high benefit-to-risk ratio of these medications can be maintained.