Ivermectin alone or in combination with benzyl benzoate in the treatment of human immunodeficiency virus-associated scabies

Solvent exchange-motivated and tunable in situ forming implants sustaining triamcinolone acetonide release for arthritis treatment

Arthritis is a syndrome characterized by inflammation in the joints. Triamcinolone acetonide (TA) was used as an anti-inflammatory agent in the treatment of this disease. However, there are limitations to its clinical application, including rapid clearance from the joint cavity, potential joint damage from multiple injections, and adverse joint events. To address these drawbacks, we developed a tunable in situ forming implant loaded with TA. This injectable polymer solution utilized poly (lactic-co-glycolic acid) (PLGA) as an extended-release material. When injected into the joints, the solution solidifies into implants through a solvent exchange in the aqueous environment. The implants demonstrated robust retention at the injection site and released TA over several weeks even months through diffusion and erosion. By adding different proportions of low water-miscible plasticizers, the release period of the drug could be precisely adjusted. The plasticizers-optimized implants exhibited a tough texture, enhancing the therapeutic efficiency and drug safety in vivo. In arthritic model studies, the tunable TA-loaded implants significantly reduced swelling, pain, and motor discoordination, and also showed suppression of arthritis progression to some extent. These findings suggested that TA-loaded ISFI holds promise for managing inflammatory disorders in individuals with arthritis.

Antiviral effects and mechanisms against EV71 of the novel 2-Benzoxyl-Phenylpyridine Derivatives

A series of 2-Benzoxyl-Phenylpyridine derivatives were evaluated for their potential antiviral activities against EV71. The preliminary assays indicated that some of these compounds exhibited excellent antiviral effects on EV71, they could effectively inhibit virus-induced cytopathic effects (CPEs), reduce progeny viral yields, and present similar or better antiviral activities compared to the positive control drug ribavirin. Among these derivatives, compounds WY7, WY13 and WY14 showed the most potency against EV71. Investigation of the underlying mechanism of action revealed that these compounds target EV71 replication in cells post infection, they could profoundly inhibit viral RNA replication and protein synthesis, and inhibit virus-induced cell apoptosis. Further experiments demonstrated that compound WY7 potently inhibited the activity of the EV71 3C protease (3Cpro), and to some extent, it affected the activity of 3D polymerase (3Dpol), thus blocking viral replication, but not the activity of the 2A proteinase (2Apro). Modeling of the molecular binding of the 3Cpro-WY7 complex revealed that compound WY7 was predicted to insert into the substrate-binding pocket of EV71 3Cpro, blocking substrate recognition and thereby inhibiting EV71 3Cpro activity. These results indicate that these compounds might be feasible therapeutic agents against EV71 infection and that these compounds may provide promising lead scaffolds for the further design and synthesis of potential antiviral agents.

Ivermectin: From theory to clinical application

Approximately 250 million people have been using ivermectin (IVM) annually to combat many parasitic diseases including filariasis, onchocerciasis, strongyloidiasis, scabies and pediculosis. Many clinical studies have proven its efficacy against these diseases and have reported the optimum dose and duration of treatment. Moreover, its antiparasitic range has increased to cover more parasitic infections, but it still requires further exploration, e.g. for trichinosis and myiasis. Furthermore, IVM showed high efficacy in killing vectors of disease-causing parasites such as mosquitoes, sandflies and tsetse flies. The World Health Organization (WHO) has managed many control programmes involving the use of IVM to achieve elimination of onchocerciasis and lymphatic filariasis and to reduce malaria transmission. However, IVM is not exempt from the possibility of resistance and, certainly, its intensive use has led to the emergence of resistance in some parasites. Recent research is investigating the possibility of novel drug delivery systems for IVM that increase its potential to treat a new range of diseases and to overcome the possibility of drug resistance. This review highlights the most common human uses of IVM, with special reference to the new and promising properties of IVM.

Metal-Support Cooperative Effects in Au/VPO for the Aerobic Oxidation of Benzyl Alcohol to Benzyl Benzoate

This paper studies the cooperative effect of Au nanoparticles deposited on vanadyl pyrophosphate oxide (VPO) in the liquid phase oxidation of benzyl alcohol. VPO was prepared using the classical method by thermally treating VOHPO₄·0.5H₂O precursor in reacting atmosphere at 420 °C for a period of 72 h. Au nanoparticles were deposited by incipient wetness method. The catalysts were characterized by means of XRD, TEM, XPS and Raman. The bulk VPO catalyst contains vanadyl pyrophosphate phase ((VO)₂P₂O₇), and a small amount of VOPO₄. The catalytic system exhibits a high activity in the base-free liquid phase oxidation of alcohols compared to Au on activated carbon, classic catalyst used for this type of reaction. Au/VPO showed a high peculiar selectivity to benzyl benzoate (76%), an important product used in the pharmaceutical and perfume industries. This behavior might be ascribed to the presence of strong acid sites of VPO, as determined by liquid phase titration. Stability tests performed on Au/VPO showed a deactivation of 10% after the first run, but a constant conversion along the following five cycles. This phenomenon can be attributed to the increase of mean Au particle size (from 19.1 to 23.4 nm) after recycling tests as well as the partial leaching of Au and V in the reaction media. Moreover, XRD evidenced a modification in the VPO structure with the partial formation of VOHPO₄·0.5H₂O phase.

A Review of Scabies: An Infestation More than Skin Deep

Human scabies, a common infestation, has a worldwide distribution with a variable impact and presentation depending on the clinical situation. In developed, high-income settings, health institution and residential home outbreaks challenge health and social care services. In resource-poor settings, it is the downstream sequelae of staphylococcal and streptococcal bacteraemia, induced by scratching, which have a significant impact on the long-term health of communities. Over the past decade scabies has been recognised as a “neglected tropical disease” (NTD) by the World Health Organisation, has an accepted practical system of global diagnostic criteria and is being adopted into integrated programmes of mass drug administration for NTDs in field settings. This review seeks to summarise the recent advances in the understanding of scabies and highlight the advocacy and research headlines with their implication for diagnosis and management of outbreaks and individuals. In addition, it will indicate the priorities and questions that remain.

Biomedical applications of microemulsion through dermal and transdermal route

Microemulsions are thermodynamically stable, transparent, colloidal drug carrier system extensively used by the scientists for effective drug delivery across the skin. It is a spontaneous isotropic mixture of lipophilic and hydrophilic substances stabilized by suitable surfactant and co-surfactant. The easy fabrication, long-term stability, enhanced solubilization, biocompatibility, skin-friendly appearance and affinity for both the hydrophilic and lipophilic drug substances make it superior for skin drug delivery over the other carrier systems. The topical administration of most of the active compounds is impaired by limited skin permeability due to the presence of skin barriers. In this sequence, the microemulsion represents a cost-effective and convenient drug carrier system which successfully delivers the drug to and across the skin. In the present review work, we compiled various attempts made in last 20 years, utilizing the microemulsion for dermal and transdermal delivery of various drugs. The review emphasizes the potency of microemulsion for topical and transdermal drug delivery and its effect on drug permeability.

Selective Benzyl Alcohol Oxidation over Pd Catalysts

In the last decades, the selective liquid phase oxidation of alcohols to the corresponding carbonyl compounds has been a subject of growing interest. Research has focused on green methods that use “clean” oxidants such as O2 in combination with supported metal nanoparticles as the catalyst. Among the alcohols, benzyl alcohol is one of the most studied substrates. Indeed, benzyl alcohol can be converted to benzaldehyde, largely for use in the pharmaceutical and agricultural industries. This conversion serves as model reaction in testing new potential catalysts, that can then be applied to other systems. Pd based catalysts have been extensively studied as active catalytic metals for alcohol oxidation for their high activity and selectivity to the corresponding aldehyde. Several catalytic materials obtained by careful control of the morphology of Pd nanoparticles, (including bimetallic systems) and by tuning the support properties have been developed. Moreover, reaction conditions, including solvent, temperature, pressure and alcohol concentration have been investigated to tune the selectivity to the desired products. Different reaction mechanisms and microkinetic models have been proposed. The aim of this review is to provide a critical description of the recent advances on Pd catalyzed benzyl alcohol oxidation.

Benzyl Benzoate-Loaded Microemulsion for Topical Applications: Enhanced Dermatokinetic Profile and Better Delivery Promises

Benzyl benzoate (BB) is one of the oldest drugs used for the treatment of scabies and is recommended as the "first-line intervention" for the cost-effective treatment of the disease. Though a promising candidate, its application is reported to be associated with irritation of the skin and eye, resulting in poor patient compliance. Hence, the present study aims to develop BB-loaded topical microemulsion for the safer and effective delivery of BB. Pseudo-ternary phase diagrams with BB as the oily phase itself, along with Tween 80 as surfactant, and mixture of phospholipid and ethanol as the co-surfactant along with aqueous solution as the external phase were constructed and various compositions were formulated. The optimized formulation was characterized for particle-size, zeta-potential, drug-content, globule-morphology pH, and refractive-index, whereas evaluated for skin permeation, retention, compliance, and dermatokinetics. The nanosized formulation offered threefold higher drug permeation vis-a-vis plain drug solution across LACA mice abdominal skin. The drug retention of the selected formulation was nearly twice of that from the marketed product, assuring depot formulation and sustained release. The skin histopathology revealed the non-irritant nature of the formulation, as no changes in the normal skin histology were observed. The dermatokinetic studies confirmed better permeation and enhanced skin bioavailability of BB to epidermis as well as dermis vis-à-vis the conventional product. The results indicate that the developed lipid-based microemulsion hydrogel can alleviate the concerns associated with BB and can provide a better and safer delivery option in substantial amounts to various skin layers.

A novel clinical grading scale to guide the management of crusted scabies

Background

Crusted scabies, or hyperinfestation with Sarcoptes scabiei, occurs in people with an inadequate immune response to the mite. In recent decades, data have emerged suggesting that treatment of crusted scabies with oral ivermectin combined with topical agents leads to lower mortality, but there are no generally accepted tools for describing disease severity. Here, we describe a clinical grading scale for crusted scabies and its utility in real world practice.

Methodology/Principal Findings

In 2002, Royal Darwin Hospital (RDH), a hospital in tropical Australia developed and began using a clinical grading scale to guide the treatment of crusted scabies. We conducted a retrospective observational study including all episodes of admission to RDH for crusted scabies during the period October 2002–December 2010 inclusive. Patients who were managed according to the grading scale were compared with those in whom the scale was not used at the time of admission but was calculated retrospectively. There were 49 admissions in 30 patients during the study period, of which 49 (100%) were in Indigenous Australians, 29 (59%) were male and the median age was 44.1 years. According to the grading scale, 8 (16%) episodes were mild, 24 (49%) were moderate, and 17 (35%) were severe. Readmission within the study period was significantly more likely with increasing disease severity, with an odds ratio (95% CI) of 12.8 (1.3–130) for severe disease compared with mild. The patients managed according to the grading scale (29 episodes) did not differ from those who were not (20 episodes), but they received fewer doses of ivermectin and had a shorter length of stay (11 vs. 16 days, p = 0.02). Despite this the outcomes were no different, with no deaths in either group and a similar readmission rate.

Conclusions/Significance

Our grading scale is a useful tool for the assessment and management of crusted scabies.

Crusted scabies is a severe skin condition caused by a microscopic parasitic mite. It occurs in people whose immune system does not react properly to the mite and it leads to crusting and cracking of the skin and can cause death. The usual treatment for crusted scabies is a tablet called ivermectin combined with anti-scabies skin creams. However, there is no current method of measuring the severity of crusted scabies and thus deciding how long to continue the treatment for. We have developed a grading scale based on examination of the skin, which classifies patients as mild, moderate or severe, and uses this grading to suggest the duration of treatment. We have trialed this grading scale over an 8-year period in 49 episodes of crusted scabies requiring hospital admission, and have found that it leads to a shorter length of hospital stay and treatment, but equivalent outcomes compared to those who were treated without the use of the grading scale.

Comparison of safety, efficacy, and cost effectiveness of benzyl benzoate, permethrin, and ivermectin in patients of scabies

OBJECTIVE

To compare three treatment modalities in scabies for safety, efficacy, and economy in a local population of Nagpur.

MATERIALS AND METHODS

This was a prospective, randomized, comparative clinical trial conducted in 103 participants, randomly allocated to three groups. First group received benzyl benzoate (BB) 25% lotion, second group received permethrin 5% cream, whereas third group received tablet ivermectin 200 mug/kg as a single dose. The participants were recalled after one week for follow-up evaluation. If there were no signs of cure, the same intervention was repeated. The participants were followed up for two weeks for cure rate, adverse drug reaction (ADR) monitoring, and postintervention observation. The follow-up was stopped after two weeks.

STATISTICS

Fischer's exact test using Graph pad Instat v 3.05.

RESULTS

Ivermectin showed 100% cure rate after two weeks of treatment. Permethrin decreased pruritus by 76% at the end of one week and had significantly better cure rate than ivermectin. At the end of two weeks treatment, this finding was reversed, that is, cure rate in ivermectin group was 100%. For cost-effectiveness analysis, treatment regimens were formulated hypothetically for comparison from Markov population tree for decision analysis. It was found that BB and ivermectin each consecutively for two weeks were most cost effective regimens giving complete cure in four weeks, while ivermectin was the fastest regimen giving the same results in two weeks.

CONCLUSION

Benzyl benzoate as first line intervention and ivermectin in the remaining gave best cost-effective results in the study patients of scabies.

Treatment of skin and soft tissue infections in the elderly: A review

BACKGROUND

Skin and soft tissue infections (SSTIs) have become the second most common type of infection among persons residing in long-term care facilities.

OBJECTIVE

The purpose of this article was to review the latest information on SSTIs among the elderly, including age-related changes, challenges, and treatment strategies in the era of emerging bacterial resistance.

METHODS

Relevant information was identified through a search of MEDLINE (1970-April 2010), International Pharmaceutical Abstracts (1970-April 2010), and Google Scholar using the terms skin and soft tissue infection, skin and skin structure infection, cellulitis, treatment guidelines, and elderly. Additional publications were found by searching the reference lists of the identified articles. Trials published since 1970 were selected for this review if they prospectively evaluated mostly adults (≥18 years of age), included >50 patients, and reported diagnostic criteria as well as clinical outcomes in patients treated for simple or complicated SSTIs.

RESULTS

Fifty-eight of 664 identified studies were selected and included in this review. A search of the literature did not identify any prospective clinical trials that were conducted exclusively in the elderly. Information on the treatment of SSTIs in the elderly was based solely on clinical studies that were conducted in adults in general. As recommended by the Infectious Diseases Society of America (IDSA) 2008 update, SSTIs should be suspected in elderly patients who have skin lesions and present with a decline in functional status, with or without fever. Patients who present with symptoms of systemic toxicity should be hospitalized for further evaluation. Current challenges in the management of SSTIs include the rapid emergence of community-acquired, methicillin-resistant Staphylococcus aureus (CA-MRSA), the emergence of macrolide-resistant streptococci within the past decade, and the lack of a reliable algorithm to differentiate potentially life-threatening SSTIs that require aggressive interventions and prompt hospitalization from those that can be managed in an outpatient setting. S aureus was the most common cause of SSTIs, being isolated in 42.8% (5015/11,723) of wounds, followed by streptococci. Common SSTIs in the elderly such as shingles, diabetic foot infections, infected pressure ulcers, and scabies, and their treatment were also discussed. Based on reviews of published trials, treatment of simple SSTIs generally consisted of administration of agents with activity against S aureus and Streptococcus species such as a penicillinase-resistant β-lactam, a first-generation cephalosporin, or clindamycin. Broadening of the antimicrobial spectrum to include gram-negative and anaerobic organisms should be implemented for complicated SSTIs such as diabetic foot infections and infected pressure ulcers. Local rates of MRSA, CA-MRSA, and macrolide-resistant streptococci should be considered when selecting empiric therapy.

CONCLUSIONS

A search of the literature did not identify any prospective clinical trials on the treatment of SSTIs in the elderly; therefore, it is recommended to follow treatment based on the current IDSA guidelines. More research and publications are needed to establish proper selection of antimicrobial agents, treatment strategies, and duration of therapy of SSTIs in the elderly population.

European guideline for the management of scabies, 2010

Transmission of the mite Sarcoptes scabiei generally occurs by protracted direct body contact; although in crusted scabies, transmission also occurs via infected clothing or bedding. Diagnosis is usually clinical and topical antiscabietics are the mainstay of treatment. Oral ivermectin is not licensed in most countries, but may have a role in certain patients. Treatment of sexual contacts is indicated.

Scabies and pyodermas--diagnosis and treatment

Scabies and pyodermas are two of the commonest skin infections in tropical settings. They affect large numbers of people, particularly children, and account for a large burden of disease for peripheral health care teams. Despite this there have been significant advances in our knowledge of these diseases, their impact and their management. However there is a need to evaluate these developments in this specific setting, tropical health and in the context of communities with limited resources. This section will describe these advances and the challenges that remain.

Scabies

Scabies is an ectoparasite caused by the mite Sarcoptes scabiei var hominis, an obligate human parasite. There are about 300 million cases of scabies in the world each year. Common predisposing factors are overcrowding, immigration, poor hygiene, poor nutritional status, homelessness, dementia, and sexual contact. Direct skin-to-skin contact between 15 and 20 minutes is needed to transfer the mites from one person to another. The diagnosis suspected with a clinical history of itch, worse at night, affecting other family members, clinical distribution, and appearance. Definite diagnosis relies on microscopic identification of the mites, eggs, or fecal pellets with 10% potassium hydroxide, ink enhancement, tetracycline fluorescence tests, or mineral oil; other methods include: epiluminescence light microscopy and S. scabiei DNA. The most commonly used treatment modalities are permethrin and ivermectin. Persistence of symptoms for 2-6 weeks after successful treatment is common. Most recurrences are because of reinfection from untreated contacts.

The Scourge of Sarcoptes: Oral Ivermectin for Scabies

OBJECTIVE

To review the use of the oral antiparasitic ivermectin in the treatment of scabies, with an emphasis on its use in the elderly and in long-term care settings.

DATA SOURCE

A MEDLINE/PUBMED search was conducted to identify pertinent studies, case reports, letters, and reviews in the English language. All articles published from 1980 to October 2003 were reviewed. Additional references were obtained from the bibliographies of these articles.

STUDY SELECTION

All studies evaluating ivermectin in the context of scabies mite infestation.

DATA SYNTHESIS

The semisynthetic macrocyclic lactone ivermectin has been available since the early 1980s as a broad-spectrum antiparasitic agent in animals and humans. This agent, which works by suppressing motor nerve conduction leading to parasite paralysis and death, was first used in ectoparasitic diseases (i.e., those caused by lice and mites) shortly after commercial introduction. A large body of literature, mainly uncontrolled case reports and series, has since evolved. However, these reports and results of the small number of placebo- and/or active-controlled studies have demonstrated the favorable response of both classic and crusted scabies to single- and multiple-dose oral ivermectin. Adverse reactions to the drug are uncommon, with the exception of a transient, new onset, or mild increase in existing pruritus soon after drug ingestion, which is thought to be a hypersensitivity reaction to dead mites and/or their products.

CONCLUSION

Oral ivermectin may prove to be a time- and labor-saving alternative to topical scabicide treatments, especially in the institutional setting where labor shortages make the management of scabies outbreaks a true challenge. However, the use of this agent does not change the need to decontaminate the environment (clothing, bedding, bed clothes, and, in selected cases, floors and walls) in order to truncate an outbreak and prevent reinfestation.

Scabies: molecular perspectives and therapeutic implications in the face of emerging drug resistance

Limited effective treatments, coupled with recent observations of emerging drug resistance to oral ivermectin and 5% permethrin, raise concerns regarding the future control of scabies, especially in severe cases and in endemic areas where repeated community treatment programs are in place. There is consequently an urgent need to define molecular mechanisms of drug resistance in scabies mites and to develop and assess alternative therapeutic options, such as tea tree oil, in the event of increasing treatment failure. Molecular studies on scabies mites have, until recently, been restricted; however, recent advances are providing new insights into scabies mite biology and genetic mechanisms underlying drug resistance. These may assist in overcoming many of the current difficulties in monitoring treatment efficacy and allow the development of more sensitive tools for monitoring emerging resistance.

Scabies and Pediculosis Pubis: An Update of Treatment Regimens and General Review

Ectoparasites continue to be a common cause of skin disease throughout the world. The present article dissects the epidemiological profile and treatment of both Sarcoptes scabiei variant hominis and pediculosis pubis.

[Systemic adverse reactions with ivermectin treatment of scabies]

BACKGROUND

Scabies is a common parasitic infestation and is very difficult to eradicate from institutions. Ivermectin is used extensively thanks to its efficacy and ease of use through oral administration; it was approved for the treatment of scabies in humans in 2001 in France. Most of the adverse effects noted with this drug have been seen during treatment of onchocerciasis and other filarial disease, but they are rare in the treatment of scabies. We report side effects with ivermectin in two elderly patients with scabies.

CASES REPORT

A 72-year-old man was referred for scabies and was treated with benzyl benzoate (Ascabiol) and ivermectin (200 microg/kg) in a single dose. Two days later, the patient presented abdominal pain and nausea. Laboratory tests revealed cytolysis tests for other causes of hepatitis were negative. Within two weeks, liver function had returned to normal. Hepatitis due to ivermectin was diagnosed. An 86-year-old woman hospitalised for scabies was treated with benzyl benzoate and a single dose of ivermectin (200 microg/kg). She developed sinus tachycardia and asthma 3 days later. Screening for embolic, cardiac and infectious origins was found. Toxicity of ivermectin was suspected.

DISCUSSION

Since the introduction of ivermectin for the treatment of scabies, reports of adverse events are rare although this drug can cause cardiac dysfunction and liver disease in other indications. In our cases, the causal relationship with ivermectin is probable and care must be taken, particularly in the elderly, the population in which this drug is probably most widely prescribed.

Scabies

Scabies is a neglected parasitic disease that is a major public health problem in many resource-poor regions. It causes substantial morbidity from secondary infections and post-infective complications such as acute post-streptococcal glomerulonephritis. Disease control requires treatment of the affected individual and all people they have been in contact with, but is often hampered by inappropriate or delayed diagnosis, poor treatment compliance, and improper use of topical compounds such as permethrin, lindane, or benzyl benzoate. In addition to concerns over toxicity with such compounds, parasite resistance seems to be increasing. Oral ivermectin is an alternative that has been used successfully in community control programmes. Plant derivatives such as turmeric, neem, and tea tree oil are also promising future treatments. The disease is strongly associated with poverty and overcrowding, and the associated stigma can ostracise affected individuals. Treatment of scabies in poor countries needs to integrate drug treatment programmes with efforts to improve the socioeconomic conditions and education programmes to reduce stigma. We expect the future to bring more sensitive and specific clinical and laboratory-based diagnostic methods, as well as new therapeutic strategies.

Ivermectin: pharmacology and application in dermatology

Ivermectin is a synthetic derivative of the antiparasitic class of compounds known as avermectins. It is a macrolide endectocide with activity against both endoparasites with cutaneous tropism (Strongyloides stercoralis, Ancylostoma braziliense, Cochliomyia hominivorax, Dermatobia hominis, Filaria bancrofti, Wucheria malayi, Onchocerca volvulus, Loa-loa) and ectoparasites such as Sarcoptes scabies, Pediculus humanus, Demodex folliculorum, and Cheyletiella sp. Ivermectin is of great interest in the treatment of patients with different forms of scabies, head lice, demodecidosis, cutaneous larva migrans, cutaneous larva currens, myiasis, and filariasis.

Treatment of scabies: newer perspectives

Scabies is a common dermatological problem managed by general physicians, family physicians, and dermatologists. Scabies manifests itself in various forms in different individuals. The treatment of scabies has undergone developments with the evolution of new treatment strategies and antiectoparasitic drugs. The advent of drugs such as permethrin and ivermectin has revolutionised treatment. Management of scabies not only includes prescribing the drugs but also educating patients properly about the method of application of the drug. Treatment failures may result for various reasons and must be managed appropriately.

[Ivermectin]

Ivermectin is a semi-synthetic derivative of a macrocyclic lactone. It causes paralysis in many nematodes and arthropodes because of its effect on ion-channels in cell membranes. Ivermectin was first used in veterinary medicine. In man, it was shown to be microfilaricid against Onchocerca volvulus. Most of the adverse reactions following treatment were mild, without the systemic and ocular side effects usually complicating diethylcarbamazine therapy. In endemic areas after repeated administration of ivermectin, a dramatic reduction in dermal microfilarial load was observed, resulting in a decrease in transmission. There was a significant decrease in the prevalence of anterior segment lesions in the eyes and acute onchocercal skin disease. Moreover, ivermectin also exhibited microfilaricidal activity against Wuchereria bancrofti and Brugia malayi. Annual mass treatment with a single dose of diethylcarbamazine alone, or associated with ivermectin, was initiated in endemic areas for lymphatic filariasis. The preliminary results showed a decrease in the reservoir of microfilariae and rate of transmission, a reduction in the frequency of clinical lymphatic abnormalities due to bancroftan filariasis. In Loa loa infections ivermectin decreases microfilaremia, but serious adverse events such as encephalopathy can be induced in patients with high rate of microfilaremia. Ivermectin appears to be the drug of choice in Strongyloides stercoralis infections, a single dose is highly effective with less frequent side effects than thiabendazole. Oral ivermectin is an alternative to topical scabicides, it appears as effective as local treatment for common scabies, but there are few comparative studies. The best indications for ivermectin in this ectoparasitic infection could be the outbreak in institutions and crusty scabies, but in association with topical treatment. The precise position of this agent in the treatment of scabies remains to be specified. Ivermectin is also affective in the treatment of ascariasis and cutaneous larva migrans. It could also be a promising treatment for head lice.

Ivermectin

Ivermectin is a potent antiparasitic drug and the first commercially available member of a new class of drugs (macrocyclic lactones) that has been approved for human use. Ivermectin has already proven to be highly effective in the elimination of river blindness as a public health burden. Side effects have been minor, and patient acceptance is good. Promising results in off-label applications for ectoparasitic infestations are increasingly important as resistance to topical therapy becomes more prevalent Ivermectin represents an advance in the therapeutic armamentarium and should be considered in appropriate cases.

Current treatments for scabies

Scabies is a frequent interhuman ectoparasitic infection. Several treatments are available worldwide. There are local treatments: synthetic pyrethrins, benzyl benzoate, lindane, crotamiton. Recently a few studies were published concerning ivermectin, systemic antiparasitic agent use in onchocercosis treatment. We reviewed the literature with an evidence-based medicine method. We attempt to answer two questions in particular: what is the treatment of choice for common scabies in a patient otherwise in good health? What is the role of systemic ivermectin? We also report specific situations. Among local treatments, studies are heterogeneous according to products, countries, group of treated patients, with or without contact subjects, and the method of treatment application. There are very few high proof-level controlled studies. In France, a combination of benzyl benzoate 10% and sulfiram 2% is used most, according to professional consensus. The most studied product is the cream permethrin 5%, available in the USA and UK. Its efficacy seems slightly superior to lindane and less toxic. It is more efficient than crotamiton. There is no study comparing benzyl benzoate and permethrin. Concerning systemic ivermectin, five controlled studies showed its efficiency in common scabies. But its relative efficiency over local treatment has not been established. A few open studies showed its efficacy in institutional epidemic, profuse scabies and in HIV-positive patients. Local treatment of choice in common scabies remains to be determined among the four principal molecules. There is no study comparing permethrin or esdepallethrin to benzyl benzoate. In what cases should we prescribe crotamiton or lindane? Indication of ivermectin seems proved in common scabies and probably for HIV-positive patients. It remains to be determined if it should be prescribed in the first instance, be double or triple, be associated or not with local treatment. In case of keratotic scabies, ivermectin seems interesting with two applications within 1 week, and should be associated with local treatment (duration remains to be defined). Ivermectin is probably useful in institutional epidemic, and therapeutic attitude remains to be defined. Ivermectin seems to have little or no risk. Treatment must be adapted case-by-case, according to feasibility. It is still important to treat contacts, and modality of this treatment remains to be specified.

Scabies and pediculosis pubis: an update of treatment regimens and general review

The ectoparasites scabies and pediculosis pubis are common causes of skin rash and pruritus worldwide. They are transmitted primarily by person-to-person spread and are generally associated with low morbidity. The preferred treatment for scabies has generally been topical agents such as lindane and permethrin. Recently, ivermectin has demonstrated good efficacy in the treatment of scabies, and it may be of particular use in institutional outbreaks and in communities in which scabies is endemic. Combination treatment with topical agents and oral ivermectin may be necessary for crusted scabies. Treatment of pediculosis pubis is best accomplished with topical permethrin, lindane, or pyrethrins with piperonyl butoxide. Although resistance to these topical agents has been reported in head lice, decreased efficacy in the treatment of pediculosis pubis has not been reported.

Ivermectin in scabies

The standard treatment for scabies has long been based on topical scabicides. Ivermectin, a broad-spectrum anti-parasitic agent, was first used in veterinary medicine. This drug, active against nematodes and arthropods, is used in humans for the treatment of filariasis. For the past few years worldwide reports on the use of ivermectin in human scabies have suggested that this drug could be an alternative oral therapy.

Pharmacotherapy of ectoparasitic infections

Epizoonoses such as scabies, lice and cimicosis are common, vexing disorders that occur worldwide. Historically, many treatment modalities have been employed in the management of these disorders, and most of the drugs described in this review are of historical interest and no longer recommended or in widespread use because of their wide spectrum of adverse effects. More recently, reports documenting resistance against various antiectoparasite drugs, complicated and severe courses of the diseases, and adverse effects of drug therapy have prompted the development of new treatment strategies and drugs for optimal disease management. Because the strategies currently recommended for the treatment of ectoparasites differ worldwide, this review proposes a rational approach to selecting the best therapeutic agent by comparing the pharmacokinetics, pharmacodynamics, drug efficacy and adverse effects. A literature search of the currently Internet accessible libraries PubMed, Medline and Ideal library, of citations of articles found there, and from communications with the Federal Institute for Drugs and Medical Devices, Germany, was conducted based on this approach. One major observation of this literature search is that permethrin is the treatment of choice for lice and scabies in the US and in Great Britain, whereas lindane is still recommended for scabies in most other European countries because of its longer-standing record of effectiveness. Although permethrin has not yet been proven to be more effective than lindane in treating infections with these ectoparasites, it currently appears to have the best efficacy versus safety profile of topical treatments for scabies and lice. Ivermectin is a newer oral drug for the treatment of ectoparasites, which has been used with great success in the treatment of onchocercosis and other endoparasites. Although ivermectin appears to be a promising drug, its role in the treatment of ectoparasitic infections will be clarified as more study data become available. Finally, it is important to emphasise the clinical aspects of ectoparasite therapy and that providing the patient with optimal instructions on the use of topical therapeutics is of great importance in avoiding adverse effects and assuring complete removal of the ectoparasite, thereby avoiding the development of drug-resistance.

Review of ivermectin in scabies

BACKGROUND

Currently available topical medications for scabies are messy and need prolonged application. This leads to poor patient adherence. Emerging drug resistance to topical scabicides has made eradication of scabies difficult.

OBJECTIVE

Availability of an effective oral scabicidal agent, ivermectin (Ivm), opens a new era in the management of scabies. This review summarizes the published literature on the use of ivermectin in the treatment of scabies.

CONCLUSION

A single oral dose of ivermectin of 200 mg/kg body weight is very effective in the treatment of human scabies. A second dose 7-10 days later substantially improves the cure rate. This suggests that ivermectin may not be effective against all the stages in the life cycle of the parasite. Endemic and epidemic scabies in institutions are better treated with Ivm. Crusted scabies ideally should be treated with a combination of Ivm and topical scabicides. Other standard measures and precautions should be taken. Additional controlled studies using a higher single oral dose or using parenteral or topical forms of Ivm are needed. The safety of Ivm in children less than 5 years old and in pregnant women has to be established. The U.S. FDA has not yet approved the drug for the treatment of human scabies.