What are the side effects of topical terbinafine, ketoconazole, DMSO (Dimethyl Sulfoxide), and ibuprofen for nail fungus treatment?

Side Effects of Topical Treatments for Nail Fungus

Topical treatments for nail fungus can cause various side effects, with terbinafine having the most favorable safety profile compared to ketoconazole, DMSO, and ibuprofen.

Topical Terbinafine

Terbinafine acts by inhibiting squalene epoxidase, which is essential for ergosterol biosynthesis in the fungal cell wall 1. As a topical agent:

• Common side effects:

  • Mild skin irritation
  • Redness at application site
  • Itching
  • Burning sensation

• Rare side effects:

  • Contact dermatitis
  • Allergic reactions

Terbinafine is generally well tolerated when applied topically, with significantly fewer systemic side effects compared to oral administration 2, 3.

Topical Ketoconazole

Ketoconazole cream has been associated with several side effects:

• Common side effects (5.0% of patients) 4:

  • Severe irritation
  • Pruritus (itching)
  • Stinging sensation

• Rare side effects 4:

  • Painful allergic reactions
  • Contact dermatitis (associated with sodium sulfite or propylene glycol excipients)

DMSO (Dimethyl Sulfoxide)

DMSO has several notable side effects when used topically 5:

• Common side effects:

  • Transient stinging sensation, especially on denuded areas
  • Temporary increase in temperature at application site
  • Distinctive garlic or oyster-like odor on breath (very noticeable)
  • Unpleasant taste sensation

• Serious concerns:

  • Enhances percutaneous absorption of other topically applied medications
  • May potentiate effects of drugs administered systemically
  • Can have deleterious effects on fabrics, plastics, and other materials
  • Potential for lens changes and cataracts with prolonged high-dose exposure

• Drug interactions:

  • Should not be used concurrently with other topical medications at the same site
  • May interact with medications affecting cardiovascular and central nervous systems

Topical Ibuprofen

While specific evidence for topical ibuprofen in nail fungus treatment is limited in the provided references, potential side effects include:

• Local irritation
• Redness
• Burning sensation
• Allergic contact dermatitis

Comparative Safety Considerations

1. Terbinafine appears to have the most favorable safety profile for topical application in nail fungus treatment 2, 3.

2. Ketoconazole has a moderate side effect profile with irritation being the main concern 4.

3. DMSO carries the most significant concerns due to:

   • Distinctive odor issues
   • Potential for enhancing absorption of other medications
   • Possible systemic effects
   • Risk of lens changes with prolonged use 5

4. Topical ibuprofen has limited evidence for efficacy in nail fungus and potential for local irritation.

Important Considerations for Use

• Avoid applying DMSO with other medications as it enhances absorption 5
• Allow treated areas to dry completely before contact with fabrics or materials when using DMSO 5
• Discontinue any product if severe irritation or allergic reaction occurs
• Patients with known sulfite sensitivity should avoid ketoconazole preparations containing sodium sulfite 4
• Monitor for any signs of systemic absorption, especially with DMSO-containing preparations 5

For most patients with uncomplicated nail fungus, topical terbinafine offers the best balance of efficacy and safety profile among these options 2, 3.