A research was conducted in 2001 and 2002 to evaluate the efficacy of remaining spray by using Permethrin 50EC to kill both kinds of vectors: Xenopsylla cheopis and Anopheles minimus, responsible for plague and malaria transmission, respectively. The results showed that Permethrin 50EC at the concentration of 0.5g/m2 was highly effective to kill Xenopsylla cheopis and Anopheles minimus and remained effective for 4 months
Anopheles ; Permethrin ; Culicidae

BACKGROUND

Scabies, caused by Sarcoptes scabiei var. hominis, is a prevalent and burdensome skin disease in the Philippines, ranking second in disability. Recognized as a neglected tropical disease (NTD) by the WHO, scabies management is targeted for inclusion in universal healthcare programs worldwide by 2030. Current treatment involves topical neurotoxic drugs like permethrin, but issues such as expense and inconvenience hinder compliance. Oral ivermectin, recommended by the WHO only recently, is more cost-effective and easier to administer but is considered a second-line option in clinical practice guidelines. This research aimed to determine the comparative efficacy, safety, cost-effectiveness, and acceptability of oral ivermectin, alone or in combination with topical permethrin, versus topical permethrin alone, in the treatment of classic scabies among Filipino patients.

This 4-part study was conducted from July 2021 to September 2023 and aimed to compare the efficacy, safety, cost-effectiveness, and acceptability of oral ivermectin alone or in combination with topical permethrin versus topical permethrin alone for treating classic scabies among Filipino patients. Quantitative methods included a systematic review and network meta-analysis of 38 randomized controlled trials (RCTs) and a pharmacoeconomic evaluation using decision tree modeling. Qualitative methods involved a multiple case study of patient experiences and perceptions and in-depth interviews with physicians.

There seems to be comparable efficacy between oral ivermectin and permethrin, with limited evidence favoring the combination ivermectin/permethrin regimen. Adverse events were minor, and cost-effectiveness analyses favored ivermectin-based regimens over permethrin. Patient and physician perspectives supported the effectiveness of all treatments, with oral ivermectin recognized as safe but underutilized.

Evidence synthesis suggests that oral ivermectin, especially in combination with permethrin, could be a viable and cost-effective alternative for scabies treatment in the Philippines. The optimal dosing regimen, safety in specific populations, and factors influencing treatment choice need further exploration. Recommendations include advocating for oral ivermectin inclusion in regulatory guidelines and national formulary, considering it as a first- or second- line treatment, and conducting further research, including mixed-methods designs, to confirm efficacy, safety, and cost-effectiveness in different settings. Shared decision-making, considering ethical, logistical, socioeconomic, and psychological aspects, is crucial in implementing effective scabies control programs.

Background and Objective: Oral ivermectin is recommended as an alternative to topical permethrin in Japanese, European, and CDC-STI guidelines for treating classic scabies. The combination of oral ivermectin and topical permethrin is also used in some settings. Partial economic evaluations conducted in India and Egypt have conflicting results, and no cost-effectiveness analysis in the Philippines has compared ivermectin-based regimens to permethrin for scabies treatment. We aimed to determine the cost-effectiveness of oral ivermectin, alone or in combination with permethrin, compared to permethrin, in the treatment of Filipino adult patients with classic scabies. Methods: We used a decision tree model to estimate the cost-effectiveness of two regimens, oral ivermectin alone or in combination with permethrin, compared with permethrin to treat adults and children aged five years and older with classic scabies in the outpatient setting from the household perspective in the Philippines. We estimated total costs and disability-adjusted life years (DALYs) over a one-month follow-up. Input parameters were obtained from secondary data, such as effect estimates for probabilities of clinical outcomes from a network meta-analysis, DALYs from the Global Burden of Disease 2019, and prevailing market cost in the Philippines (DPRI 2022 with recommended markup by DOH, and leading drugstores) as of August 2022. We computed for incremental cost-effectiveness ratio (ICER) and net monetary benefit (NMB) to determine which of the interventions are cost-effective. Univariate and probabilistic sensitivity analyses, and scenario analyses were conducted to assess the impact of parameter and structural uncertainty. Results: Ivermectin-based regimens are suggested to be likely cost-saving compared to permethrin in the Philippine outpatient setting. Base case analysis showed that oral ivermectin had higher cost-savings (change in cost, -1,039.31; change in DALYS, 0.00027), while combination oral ivermectin/permethrin had higher DALYs averted (change in cost, PhP -1,019.78; change in DALYs, 0.00045), compared to permethrin. Combination oral ivermectin/permethrin (56%) was the most cost-effective, followed by oral ivermectin (44%) compared to permethrin (0%) through probabilistic sensitivity analysis. Estimates for ivermectin were sensitive to risk of cure for ivermectin vs permethrin using 1-way deterministic sensitivity analysis. Oral ivermectin was favored over combination oral ivermectin/permethrin at all thresholds based on the cost-effectiveness acceptability curve. Conclusion Both ivermectin-based regimens seem to be cost-saving compared to permethrin in the treatment of classic scabies in the Philippine outpatient setting. Clinicians may consider oral ivermectin, alone or in combination with permethrin as an alternative first-line or second-line treatment depending on patient preference, adverse event risk profile, availability, and economic capacity. This needs to be confirmed using primary data from Filipino patients to enhance the robustness of the findings and support evidence-based local decision-making in different settings. Less uncertainty in modelled parameters can give greater confidence in the results, which can be adopted for budget impact analysis and allow more rational resource allocation. Value of information analysis can be done to determine whether the expense of future RCTs or surveys in Filipinos to collect primary data is worth it. The cost of reducing uncertainty, if deemed worth the cost of further studies, may facilitate population-level decision-making and budget planning. Findings may further inform practice guideline development, coverage decisions, and national control program planning by providing the most cost-effective scabies intervention.
Scabies ; Ivermectin ; Permethrin ; Cost-Benefit Analysis

BACKGROUND: Permethrin shampoo is currently the first-line treatment for pediculosis capitis. However, its widespread use has resulted in the development of resistance.
OBJECTIVE: To compare aromatic oil shampoo and 1% permethrin shampoo in terms of efficacy and safety
METHOD: One hundred fifty-hour patients with active infestation were treated in this randomized, assessor-blind, controlled trial using aromatic oil or permethrin shampoo, applied once weekly for three weeks. Evaluations were conducted at baseline and a week after shampoo application. Complete cure was defined as the absence of live louse on day 21.
RESULTS: There were no significant differences between the two groups in terms of complete cure, changes in patient's quality of life and pruritus at day 21. Neither group reported any diverse effects.
CONCLUSION: The efficacy and safety of the aromatic oil shampoo was comparable to that of 1%permethrin shampoo in treating pediculosis capitis.

The resistance to various insecticides from 4 major groups (organochlorine, organophosphate, carbamate and pyrethroid) was investigated in a field strain of Culex quinquefasciatus from Baan Suan community, Nonthaburi province, Thailand by using a standard World Health Organization susceptibility test. The Baan Suan strain was completely resistant to DDT and highly resistant to deltamethrin, permethrin, fenitrothion and propoxur but this strain was still found to be highly susceptible to malathion. This strain displayed high resistance to cypermethrin since the result revealed that the resistance ratio of the 50% lethal concentration value (RR50) between the field and the laboratory strains (NIH strain) was 16. The study indicated that mosquitoes were resistant to almost all insecticide tested except malathion and this should be an alternative for Cx. quinquefasciatus control in this area. Moreover, Aedes aegypti, which is a main dengue vector in Baan Suan community was also tested with deltamethrin, permethrin and fenitrothion. The results showed that dengue mosquitoes are clearly resistant to permethrin and tolerant to deltamethrin, but was 100% susceptible to fenitrothion. The cause of insecticide resistance in Cx. quinquefasciatus may be due to the continuous use of insecticide for dengue vector control programme in Baan Suan community.
Insecticides ; Cancer resistance to treatment ; Aedes aegypti ; Culex quinquefasciatus ; Permethrin

Laboratory-bred females of Culex quinquefasciatus, Aedes aegypti and Aedes albopictus from the insectarium, Unit of Medical Entomology, Institute for Medical Research were used in the experiment. The late third stage of the F0 larvae which survived the high selection pressure of malathion, permethrin and temephos were reared and colonies were established from adults that emerged. Cx. quinquefasciatus larvae were subjected to selection by malathion and permethrin for 40 generations, Ae. aegypti larvae to malathion, permethrin and temephos for 32 generations and Ae. albopictus larvae were selected against malathion and permethrin for 32 generations and 20 generations against temephos. The rate of resistance development was measured by LC50 value. Cx. quinquefasciatus larvae developed higher resistance to malathion and permethrin compared to Ae. aegypti and Ae. albopictus. On the whole, permethrin resistance developed at a faster rate than malathion and temephos.
Permethrin ; Malathion ; Cancer resistance to treatment ; Aedes aegypti ; Aedes albopictus

The emergence of insecticide resistance in mosquito vectors was an important issue to be considered as one of factors influencing the success of vector control. The early detection of resistance could help the health personnel to plan and select appropriate alternative control measures or insecticide for effective control. Therefore biochemical assay of enzymes in mosquito was conducted to detect the emergence of insecticide resistance and to define the machanisms involved in pyrethroid resistance. Adults of Aedes aegypti from two localtities in Ratchaburi province were subjected to permethrin and deltamethrin selection in laboratory. After three generations of selection, permethrin-selected and deltamethrin-selected strains were established. Their LT 50 increased to 7.46 and 1.18 folds in the F3 strains that were selected with permethrin and deltamethrin respectively. The enzymes of these mosquitoes were assayed biochemically to study the mechanisms of resistance. The results revealed significant increase of esterase activity and monooxygenase levels in both strains when compared with labolatory susceptible strain. Glutathione-S-transferase activity was found to increase in permethrin-selected strain but not in deltamethrin-selected strain. This suggested that not only esterase and monooxygenase but also glutathione-S-transferase were associated with permethrin resistance in Ae. aegypti. The exposing of permethrin-selected and deltamethrin-selected mosquitoes to diagnostic concentration of permethrin (0.75%) and deltamethrin (0.05%) indicated no cross resistance for permethrin to deltamethrin while slight cross resistance from deltamethrin to permethrin was evident. It seemed that glutathione S-tranferase was not associated with cross resistance since its activity in deltamethrin-selected strain remained unchanged as compared with that of laboratory susceptible strain.
Cancer resistance to treatment ; Permethrin ; decamethrin ; Culicidae ; Pyrethroid insecticide

The insecticide susceptibility of Aedes aegypti larvae and adults from four areas of Ratchaburi Province, Thailand was investigated using World Health Organization standard procedures. The larvae of Ae. aegypti in all areas were found to be susceptible to temephos. The strain with the highest level of temephos resistance was subjected to temephos selection. The resistance ratios increased to 2.74-fold from their parental non selected strain after 5 generations of selection. For the adult of Ae. aegypti, the study was conducted to determine the effects of 0.75 % permethrin and 0.05 % deltamethrin impregnated paper selection on the strain having the highest with the highest LT50 level. The results showed the increase in the LT50 to 7.46 and 1.18-fold after the third selected generation with 0.75 % permethrin and 0.05 % deltamethrin respectively. Mortality rates after exposing adults to discriminating concentrations showed that field populations in Ratchaburi Province were resistant to permethrin and deltamethrin. Alternative non-chemical measures need to be used in new of the emergence of resistance in the mosquito population.
Cancer resistance to treatment ; Selection (Genetics) ; Aedes aegypti ; Permethrin ; decamethrin

Objective: To determine the efficacy of cooking coconut oil and vinegar as compared to 1% Permethrin shampoo in the treatment of Pediculosis humanus capitis in children 3 – 12 years old. Methodology: The study was conducted in Barangay 704, Zone 77 in Malate among children 3 – 12 years old. Two hundred forty-five subjects were screened and the computed sample size was 150. Subjects were randomized to three treatment groups: coconut oil (CO) group; vinegar plus coconut oil (CV) group; and 1% permethrin shampoo (PS) group. Treatments were given on the 1st and 8th day. The final level of infestation was determined on the 14th day. Cure rates, failure rates, and expenses were also determined. Results: Permethrin achieved superiority over plain coconut oil (X2=18.77 p-value = 0.00). There was no sufficient evidence to prove the superiority of permethrin over coconut-vinegar solution (X2=1.04 p-value = 0.30). Twenty-two percent (11) of the participants from the PS group developed itching and irritation. No adverse effect was reported from the CO and CV groups. Permethrin was 14 times and five times more expensive than coconut oil and vinegar plus coconut oil, respectively. Conclusion Permethrin shampoo had a cure rate of 98%. Plain coconut oil and vinegar plus coconut oil had cure rates of 68% and 94%, respectively. Plain coconut oil had the highest failure rate at 36%, vinegar plus coconut oil at 6%, and permethrin shampoo with 2%. Adverse effects were exclusive to the PS group. Plain coconut oil was the most economical but coconut oil with vinegar with its significant cure rate can be an alternative therapy to permethrin shampoo in the treatment of head lice in children.
Pediculus ; Coconut Oil ; Acetic Acid ; Permethrin ; Lice Infestations

Crusted scabies, characterized by hyperkeratosis and significant mite proliferation, is particularly prevalent in immunocompromised patients, such as those with systemic lupus erythematosus (SLE). This report presents a case of J.A., a 35-year-old female with SLE on prednisone and hydroxychloroquine, who developed pruritic erythematous papules on her palms and fingers. Over several months, these progressed to crusted hyperkeratotic plaques with fissures on her face, scalp, neck, and extremities.

Clinical evaluation revealed positive ink burrow tests and mineral oil preparation showing scabies mites and eggs. Histopathology confirmed the presence of intracorneal mites and scybala. Treatment involved permethrin 5% lotion applied daily for 14 hours over 7 days, followed by keratolytic soap and petroleum jelly twice weekly. Due to ivermectin unavailability, albendazole 400 mg was administered daily for three doses. Significant improvement was noted within two weeks.

Crusted scabies carries a high mite burden up to 4000 mites/gram of skin compared to 20 in typical scabies. The immunocompromised state in SLE patients, often marked by lower CD4+ counts and increased CD8+ T cells, lead to epidermal hyperproliferation. Early recognition and prompt combination treatment with permethrin and albendazole are essential for effective management. This case underscores the need for vigilance in diagnosing crusted scabies in patients with altered immune responses.