Cindy asked
My doctor prescribed a 12-week course of Lamisil pills for one toenail that has a fungus. It didn’t work so now she want to try Itraconazole. I’m concerned about the side effects of that medicine. Are there any safer, reasonable options to try first or am I being too paranoid about Itraconazole? Also, is it dangerous to take Itraconazole if you have a heart murmur?
Answer
Sporanox (itraconazole) and Lamisil (terbinafine) are both considered first-line oral agents for the treatment of fungal nail infections (onychomycosis) according to various medical guidelines. However, Lamisil is more commonly used first because it has higher cure rates and far fewer drug interactions than Sporanox. Nevertheless, Sporanox has a slightly wider spectrum of anti-fungal activity, and may be effective if Lamisil fails.
Below we discuss both drugs in more detail.
Sporanox (Itraconazole) For Nail Infections
Sporanox is an antifungal agent and is considered "broad-spectrum", meaning it can be effective for:
- Dermatophytes (a specific group of pathogenic fungi)
- Nondermatophytic fungus
- Candida species (i.e. yeasts)
The FDA recommended dose for toenail infections is:
- 200 mg once daily for 12 weeks.
For fingernail infections, a dosing regimen consisting of "two pulses" is recommended:
- Each pulse is dosed at 200 mg twice daily for seven days, with the same pulse given after a three-week drug free interval.
According to studies, cure rates with Sporanox range from 35% to 80% but relapse rates are high, occurring in nearly 50% of individuals who have been evaluated for up to five years after cessation of therapy.
Liver function monitoring is commonly recommended for all patients prior to initiation of therapy, especially in those with pre-existing liver impairment.
Sporanox has some serious precautions that need to be considered before use. It has been associated with causing a reduction in left ventricular ejection fraction and is contraindicated in patients with known congestive heart failure. In addition, Sporanox is an inhibitor of cytochrome (CYP) P450 3A4 and associated with many drug interactions as a majority of prescription medication is metabolized by this enzyme.
Lamisil (Terbinafine) For Nail Infections
Lamisil is anti-fungal agent that is very effective against dermatophytes but less so against much nondermatophytes molds and Candida species. If your infection is caused by a nondermatophyte, other options (like Sporanox) may be preferred. Cure rates with Lamisil are generally higher than other therapies, with reported rates around 60-80%. In addition, relapse rates are relatively low when compared to Sporanox, around 23%.
The recommended dosing regimen of Lamisil is:
- 250 mg once daily for six weeks for fingernail infections
- 250 mg once daily for 12 weeks for toenail infections.
Like other therapies, it is recommended to have your liver enzymes checked before initiating therapy with Lamisil (and during treatment as well). Lamisil does not affect CYP3A4 metabolizing enzymes as much as itraconazole and therefore is less associated with drug interactions. However, it is an inhibitor of CYP2D6.
When comparing Lamisil to other oral therapies for nail fungal infections, most studies, such as this one published in BMJ, conclude that Lamisil is superior when it comes to cure and relapse rates.
Summary: Similarities And Differences Between Lamisil And Sporanox
- Lamisil and Sporanox are both used for fungal nail infections. Sporanox has a broader spectrum of activity however and may work against pathogens not covered by Lamisil.
- Lamisil has better reported cure rate and relapse rates than Sporanox.
- Both Sporanox and Lamisil require liver function testing.
- Lamisil is dosed once daily while Sporanox can be dosed once or twice daily.
- Sporanox has more potential drug interactions than Lamisil due to CYP3A4 inhibition.
- Sporanox has more contraindications, including in those with heart failure or ventricular dysfunction.
Additional Information
Oral therapy for fungal nail infections has its drawbacks but is generally more effective than topical therapies. Nevertheless, topical therapies are generally better tolerated and offer a decent alternative. Topical therapies include:
- Penlac (Ciclopirox)
- Jublia (Efinaconazole)
The drawbacks of topical therapy include duration of therapy and cure rate. Both Penlac and Jublia are generally recommended to be used daily for 48 weeks. Even with this long duration of therapy, cure rates for Penlac are only around 7-10% and cure rates for Jublia are slightly higher, around 17%.
If you are concerned about oral therapy for your nail infection, talk to your doctor about the possibility of trying a topical product first.
