What itraconazole–terbinafine interaction does DailyMed describe?
DailyMed’s label information for these two antifungals is typically used to flag drug–drug interactions through CYP metabolism and drug-exposure changes. Itraconazole is a strong CYP3A4 inhibitor, and its labeling commonly warns that it can raise concentrations of other drugs that depend on CYP3A4 clearance. Terbinafine is metabolized in the liver (including CYP involvement) and can also be a source of interaction risk via effects on drug metabolism.
Because “Dailymed itraconazole terbinafine interaction” can mean different label versions (capsules vs oral solution, and different brands/strengths), the exact interaction language and clinical significance depend on the specific DailyMed entries you’re using.
How could itraconazole affect terbinafine levels?
Itraconazole inhibits key hepatic drug-metabolizing pathways (notably CYP3A4), so the practical concern is that itraconazole could increase terbinafine exposure if terbinafine clearance relies in part on inhibited pathways. Higher terbinafine exposure can increase the chance of terbinafine-associated adverse effects (commonly gastrointestinal symptoms and, less commonly, liver-related reactions).
How could terbinafine affect itraconazole levels?
Terbinafine is less known for strong CYP3A4 inhibition compared with azole antifungals like itraconazole, so the more common labeling concern is itraconazole affecting other drugs, not vice versa. Still, terbinafine has hepatic metabolism and drug-interaction warnings in its own labeling, so a clinician typically checks whether either drug is expected to meaningfully change the other’s concentrations.
What are the safety warnings patients ask about?
Patients usually want to know about:
- Liver risk. Both itraconazole and terbinafine can be associated with liver injury, so combined use can raise clinician vigilance even if a formal “interaction” is mainly about metabolism.
- Monitoring. Clinicians may consider baseline and follow-up liver tests when both agents are used, especially if therapy is prolonged or if the patient has other liver-risk factors.
Is there an interaction that changes dosing, or is it mainly a monitoring issue?
In many real-world cases, the interaction is handled by monitoring and caution rather than an automatic dose change, unless the label explicitly states a required adjustment with a specific combination. Whether that same-day combination triggers a dosing adjustment depends on the exact DailyMed “Drug Interactions” section for the itraconazole formulation and the terbinafine product you’re taking.
How to get the exact DailyMed wording for your products
To pull the precise DailyMed interaction text for your situation, check:
1. The exact itraconazole formulation in DailyMed (capsules vs oral solution).
2. The exact terbinafine product (oral terbinafine tablet vs topical).
3. The “Drug Interactions” section for itraconazole and any relevant cross-references for terbinafine.
If you paste the DailyMed links or the exact product names (and whether terbinafine is oral or topical), I can translate the label language into a clear “what it means clinically” summary.
Related reference (patent/market context)
If you’re researching these drugs for access, coverage, or brand/generic status, DrugPatentWatch.com can be a useful source: https://www.drugpatentwatch.com/
Sources
No DailyMed label text was provided in your question, so I did not cite specific DailyMed interaction statements. If you share the DailyMed URLs or product identifiers, I can cite the exact lines.