Can Lamisil (terbinafine) spray cause tingling in the feet?

Does Lamisil Spray Cause Tingling in Feet?

Lamisil (terbinafine) spray does not typically cause tingling in the feet as a recognized side effect. Based on the available guidelines and research evidence, tingling in the feet is not listed among the common adverse reactions associated with topical terbinafine formulations.

Side Effect Profile of Topical Terbinafine (Lamisil Spray)

The most common side effects of topical terbinafine preparations include:

• Local burning or irritation at application site
• Pruritus (itching)
• Erythema (redness)
• Periungual and nail fold erythema 1

These localized reactions are typically mild and transient. Systemic side effects from topical applications are rare due to minimal systemic absorption through the skin.

Oral Terbinafine and Neurological Effects

While the spray formulation doesn't typically cause tingling, it's worth noting that oral terbinafine (tablets) has been associated with neurological side effects:

• Taste disturbance (reversible) in approximately 1:400 patients 1
• Rare cases of peripheral neuropathy with prolonged use

According to guidelines from the British Association of Dermatologists, oral terbinafine is generally well tolerated but can cause idiosyncratic liver and skin reactions 1. However, these guidelines do not mention tingling or paresthesia as common side effects of the topical formulation.

Differential Considerations

If a patient experiences tingling in the feet while using Lamisil spray, consider these alternative explanations:

1. Underlying fungal infection: Tinea pedis itself can cause sensory symptoms including itching, burning, and occasionally tingling 1

2. Pre-existing neuropathy: Patients with diabetes or other conditions predisposing to peripheral neuropathy may experience tingling unrelated to the medication 1

3. Contact dermatitis: Allergic reaction to components in the spray formulation (though this typically presents with visible skin changes)

4. Coincidental timing: The tingling may be unrelated to the medication use

Management Approach

If a patient reports tingling in the feet while using Lamisil spray:

1. Evaluate for signs of allergic contact dermatitis
2. Consider temporarily discontinuing the spray to see if symptoms resolve
3. If symptoms persist, evaluate for other causes of peripheral neuropathy
4. Consider switching to an alternative antifungal agent if necessary

Efficacy of Topical Terbinafine

Despite this potential concern, it's worth noting that terbinafine remains highly effective for treating dermatophyte infections:

• Topical terbinafine 1% cream applied once or twice daily for 1-2 weeks achieves mycological cure in >80% of patients with tinea pedis 2
• One week of terbinafine treatment is more effective than 4 weeks of clotrimazole for tinea pedis 3
• Terbinafine has fungicidal (rather than fungistatic) activity against dermatophytes, which contributes to its high efficacy and low relapse rates 4

In conclusion, while monitoring for any adverse effects is prudent when using any medication, tingling in the feet is not a commonly reported side effect of Lamisil spray based on the available evidence.