Terbinafine Versus Itraconazole: LION's Toenail Results

A thick or discolored toenail needs a diagnosis before an oral antifungal prescription. Nail psoriasis and injury can resemble fungus. AAD¹ describes examining nails and taking a clipping or scraping for testing; the result can help choose treatment.¹

What was compared?

LION (1999) randomized 507 people; 496 entered its designated analysis population. They had confirmed dermatophyte toenail infection, averaging 70% target-nail involvement. Novartis funded it; both authors reported Novartis ties.²

Terbinafine 250 mg daily for 12 or 16 weeks was compared with itraconazole 400 mg daily for one week every four weeks, for three or four cycles.²

What cleared?

At week 72, primary cure required negative microscopy and fungal culture. Complete cure also required 100% nail clearing.²

Regimen	Negative fungal tests	Complete cure
Terbinafine, 12 weeks	81/107 (75.7%)	49/107 (46%)
Terbinafine, 16 weeks	80/99 (80.8%)	54/98 (55%)
Itraconazole, three cycles	41/107 (38.3%)	25/107 (23%)
Itraconazole, four cycles	53/108 (49.1%)	28/108 (26%)2

All four primary comparisons favored terbinafine (P < .0001). Missing outcomes were excluded from these available-case cure rates.²

What affects prescribing?

These research regimens are not instructions to start pills. The current US terbinafine tablet label specifies 250 mg daily for 12 weeks for toenails, following laboratory confirmation. Chronic or active liver disease is a contraindication; liver tests are required before treatment and periodic monitoring is recommended.³

Tell the prescriber about antidepressants, beta-blockers and other medicines, because terbinafine can alter their concentrations. Report taste or smell changes promptly: they can persist after treatment stops. Yellow eyes or skin, dark urine or pale stools warrant stopping the medicine and immediate clinical review under the label’s instructions.³

The current US Sporanox capsule label specifies continuous 200 mg daily for 12 weeks for toenails, unlike the trial’s pulse schedule. Its boxed warning covers heart failure and potentially dangerous drug interactions. It must not be used for nail fungus with ventricular dysfunction or a history of heart failure, or during pregnancy or when planning pregnancy.⁴

Ask the pharmacist to check every medicine, including supplements and nonprescription products. Sporanox can interact with medicines such as simvastatin and lovastatin; those combinations are contraindicated. Its label also warns about serious liver injury. New breathlessness or leg swelling needs immediate contact with the prescriber and stopping Sporanox as instructed by its patient information.⁴

Discuss how much the nail affects walking, shoes or daily life, and what benefit would justify an oral course. Clearing the fungus does not instantly replace damaged nail; AAD¹ says a toenail may take a year or longer to grow out. Keep the prescribed follow-up appointments and ask how the infection will be reassessed.¹

“What to Say at the Appointment” in Skin, Head to Toe recommends bringing the full product and medicine history and mentioning pregnancy plans. Put those details beside your nail-test result when reviewing the options.¹