We commonly prepare unique formulations that prescribers develop to meet specific needs of their patient population, or “tried and true” formulas acquired during professional training. Penetrant enhancers can be added to improve the extent of absorption of topically applied medications. Numerous compatible medications can be combined into a single dosage form for ease of administration. Also, a synergistic effect can be achieved when certain medications are used concomitantly.
Yeast and bacterial infections of the nails are usually the result of microscopic damage to the nail plates. The nails will have either a white, thin discoloration at the tip of the nail that starts to extend toward the cuticle, or may have a greenish-black color to the nail. A mixture of 4% thymol in alcohol used twice daily until the affected area has grown out is excellent for this condition.1 Thymol is an antibacterial and antifungal, and alcohol also reduces moisture in skin folds and cuticles.
For treatment of onychomycosis, penetration of the topical antifungal agent through the nail plate from the surface of the nail and diffusion of the systemic antifungal drug through the nail bed may increase the total amount of antifungal activity at the site of infection. Results from an initial study in patients with onychomycosis suggest that this approach can enhance the overall efficacy of therapy. Using a combination of antifungal drugs in this manner may potentially reduce the duration of therapy and allow a reduction in dose of the oral agent, which may reduce systemic adverse effects. Physicians may also consider combining topical antifungal therapy with topical urea. Urea degrades protein, including keratin — a major component of the nail plate. Potentially, urea can soften the nail plate, making it more porous and penetrable to topical antifungal drugs.2 Urea ointment (40 to 55%) can be applied to the nail twice daily for two weeks. Then, topical formulations such as clotrimazole 2% and ibuprofen 2% in DMSO USP (“apply to affected nails BID for 6 weeks”)3 or butenafine 2% and tea tree oil 5% cream can be applied to the affected nail.
A randomized, double-blind, placebo-controlled study examined the clinical efficacy and tolerability of 2% butenafine hydrochloride and 5% Melaleuca alternifolia (tea tree) oil incorporated into a cream base to manage toenail onychomycosis. Sixty outpatients (39 M, 21 F) aged 18-80 years (mean 29.6) with 6 to 36 months duration of disease were randomized to two groups (40 active therapy and 20 placebo). After 16 weeks, 80% of patients using medicated cream were cured, as opposed to none in the placebo group. Four patients in the active treatment group experienced subjective mild inflammation without discontinuing treatment. During follow-up, no relapse occurred in cured patients and no improvement was seen in medication-resistant and placebo participants.4
- Audrey Kunin, M.D. http://www.dermadoctor.com/article_Nail-Fungus_57.html (accessed June 19, 2009)
- http://www.medscape.com/viewarticle/452687_8 (accessed September 16, 2008)
- Timothy J. Scott, DPM, FACFAS, Clarion, PA
- Trop Med Int Health. 1999 Apr;4(4):284-7. Treatment of toenail onychomycosis with 2% butenafine and 5% Melaleuca alternifolia (tea tree) oil in cream.
Transdermal therapy to decrease side effects
Medications that relieve pain, reduce inflammation, and relax muscles can have side effects that are detrimental to athletic performance, such as drowsiness. However, when these medications are administered transdermally, the therapeutic benefit can be enhanced while significantly reducing the risk of adverse effects.
For example, research has shown that topically applied ketoprofen provides a high local concentration of drug below the site of application but decreases systemic exposure and significantly reduces the risk of gastrointestinal upset or bleeding. When properly compounded into an appropriate base, tissue concentrations of ketoprofen were found to be 100-fold greater below the application site (knee) compared to systemic concentrations. Muscle relaxants can be similarly prepared to minimize the risk of drowsiness.