What is your preferred oral regime with duration for treatment of onychomycosis?   

Back in the old days of the "toenail wars" between terbinafine and itraconazole, I was a speaker for both and learned that the pharmacodynamics of the two drugs favored pulsing for the latter but NOT for the former. Terbinafine does NOT leave the blood for weeks, unlike itraconazole (days), so if th...

My new favorite regimen is: terbinafine 500 mg once daily for one week, then take 3 weeks off. Repeat for 4, once weekly cycles. Sprenger et al., PMID 31487828

If no medical contraindications, I like itraconazole 100mg bid for 5 days, skip 2 days, and repeat for 2 months.

Long ago, Nardo Zaias (nail expert) published a study about this. Terbinafine for onychomycosis achieves fungicidal levels after a month and these are maintained because it is highly keratophilic. Nothing to do with blood levels. Alternate month dosing at 250mg/d for 3 cycles (3 months of active the...