Can ivermectin be administered concurrently with permethrin (Elimite) cream in a patient with persistent scabies symptoms despite two prior treatments with permethrin cream?

From the Guidelines

Yes, ivermectin can be given at the same time as permethrin cream for persistent scabies. For adults, oral ivermectin is typically prescribed at a dose of 200 micrograms per kilogram of body weight, with a second dose given 7-14 days later, as recommended by the 2015 sexually transmitted diseases treatment guidelines 1. When combined with permethrin 5% cream (applied from neck down, left on for 8-14 hours, then washed off), this dual therapy can be more effective for stubborn infestations. This combination approach is particularly useful when standard permethrin treatment has failed, as the medications work through different mechanisms - permethrin kills mites through topical contact while ivermectin works systemically to paralyze and kill the parasites. Some key points to consider when using this combination therapy include:

• Treating close contacts simultaneously to prevent reinfestation
• Washing bedding and clothing in hot water to reduce the risk of fomite transmission
• Recognizing that itching may continue for 2-4 weeks even after successful treatment due to lingering immune response to dead mites, as noted in the management of scabies guidelines 1 It's also important to consider the potential causes of persistent itching after permethrin treatment, including treatment failure, reinfestation, or post-scabetic eczema. Retreatment 2 weeks after the initial treatment regimen can be considered for those persons who are still symptomatic or when live mites are observed, and use of an alternative regimen is recommended for those persons who do not respond initially to the recommended treatment 1.

From the Research

Treatment of Scabies with Ivermectin and Permethrin

• The patient has been treated twice with permethrin cream for scabies, but the itching continues, and the question is whether ivermectin can be given at the same time as permethrin cream is applied 2, 3, 4.
• According to the studies, ivermectin and permethrin are both effective treatments for scabies, but their efficacy and safety vary depending on the dosage, application, and population being treated 3, 4, 5.
• Topical permethrin is considered the most effective treatment for classic scabies, while oral ivermectin is an effective treatment compared to placebo, but not as effective as topical permethrin 6.
• There is no clear evidence that ivermectin and permethrin cannot be used together, but the studies suggest that using them sequentially or in combination may be more effective than using them simultaneously 3, 4.

Efficacy of Ivermectin and Permethrin

• A study comparing topical permethrin 5% versus ivermectin found that twice application of permethrin with a 1-week interval was effective in 92.5% of patients, while a single dose of ivermectin provided a cure rate of 85.9% at a 2-week interval 4.
• Another study found that two applications of topical ivermectin provided a cure rate of 64.7% at the 2-week follow-up, which increased to 82.3% at the 4-week follow-up after repeating the treatment 5.
• A meta-analysis found that oral ivermectin may lead to slightly lower rates of complete clearance after one week compared to permethrin 5% cream, but there may be little or no difference in complete clearance rates after two weeks 3.

Safety of Ivermectin and Permethrin

• The studies suggest that ivermectin and permethrin are generally safe and well-tolerated, with few and mild adverse events reported 3, 4, 5.
• However, the reporting of adverse events in the included studies was suboptimal, and it is uncertain whether there is any difference in the number of participants with at least one adverse event between ivermectin and permethrin 3.