Adverse reactions to ivermectin treatment for onchocerciasis. Results of a placebo-controlled, double-blind trial in Malawi

Protective effect of vitamin C against ivermectin induced nephrotoxicity in different age groups of male wistar rats: bio-histopathological study

Ivermectin (Ive) has exceedingly efficient against several microorganisms including viruses; therefore, it could help as a potential treatment of COVID-19. Because of increasing consumption of ivermectin and vitamin C (Vit.C) in hope to treat COVID-19, and because of ivermectin nephrotoxic effects have not been fully clarified especially in juvenile age, it was conducted to examine the histopathological and biochemical effects of ivermectin on adult and juvenile kidneys, and to assess the possible protective role of Vit.C against this potential toxicity. Rats were divided to 4 subgroups (Control subgroup, Vit.C subgroup, Ive subgroup, and Vit.C+Ive subgroup), 1 week after 4 doses of ivermectin (0.4 mg/kg Ive±1.25 mg/kg Vit.C), blood samples obtained for assessment of kidney function test, part of kidneys prepared for determination of matrix metalloproteinase-9 and antioxidant enzymes essay. Other parts prepared for histopathological and ultrastructural examination. Results showed that administration of ivermectin led to attenuation in kidney function and in activities of the antioxidant enzymes and increase in matrix metalloproteinase-9 activity. In addition, there were histological damages (shrunken glomeruli, widened urinary space, cytoplasmic vacuolation and pyknotic nuclei with epithelial exfoliation, extravasated blood, and mononuclear cell infiltration) and immunohistochemistry revealed increase in percentage of Bax proapoptotic protein expression. Also, ultrastructure examination showed alteration in cell architecture. All these changes were more obvious in juvenile group while co-administration of Vit.C led to significant protection more in adult group. In conclusion, Ivermectin should be used cautiously especially in juvenile age, and co-administration of Vit.C is highly recommended.

Onchocerciasis drug development: from preclinical models to humans

Twenty diseases are recognized as neglected tropical diseases (NTDs) by World Health Assembly resolutions, including human filarial diseases. The end of NTDs is embedded within the Sustainable Development Goals for 2030, under target 3.3. Onchocerciasis afflicts approximately 20.9 million people worldwide with > 90% of those infected residing in Africa. Control programs have made tremendous efforts in the management of onchocerciasis by mass drug administration and aerial larviciding; however, disease elimination is not yet achieved. In the new WHO roadmap, it is recognized that new drugs or drug regimens that kill or permanently sterilize adult filarial worms would significantly improve elimination timelines and accelerate the achievement of the program goal of disease elimination. Drug development is, however, handicapped by high attrition rates, and many promising molecules fail in preclinical development or in subsequent toxicological, safety and efficacy testing; thus, research and development (R&D) costs are, in aggregate, very high. Drug discovery and development for NTDs is largely driven by unmet medical needs put forward by the global health community; the area is underfunded and since no high return on investment is possible, there is no dedicated drug development pipeline for human filariasis. Repurposing existing drugs is one approach to filling the drug development pipeline for human filariasis. The high cost and slow pace of discovery and development of new drugs has led to the repurposing of “old” drugs, as this is more cost-effective and allows development timelines to be shortened. However, even if a drug is marketed for a human or veterinary indication, the safety margin and dosing regimen will need to be re-evaluated to determine the risk in humans. Drug repurposing is a promising approach to enlarging the pool of active molecules in the drug development pipeline. Another consideration when providing new treatment options is the use of combinations, which is not addressed in this review. We here summarize recent advances in the late preclinical or early clinical stage in the search for a potent macrofilaricide, including drugs against the nematode and against its endosymbiont, Wolbachia pipientis.

Serious adverse reactions associated with ivermectin: A systematic pharmacovigilance study in sub-Saharan Africa and in the rest of the World

BACKGROUND

Ivermectin is known to cause severe encephalopathies in subjects infected with loiasis, an endemic parasite in Sub-Saharan Africa (SSA). In addition, case reports have described ivermectin-related serious adverse drug reactions (sADRs) such as toxidermias, hepatic and renal disorders. The aim of this study was to identify suspected sADRs reported after ivermectin administration in VigiBase, the World Health Organization's global individual case safety reports database and analyze their frequency relative to the frequency of these events after other antinematodal drugs reported in SSA and other areas of the world (ROW).

METHODS

All antinematodal-related sADRs were extracted from VigiBase. Disproportionality analyses were conducted to investigate nervous, cutaneous, psychiatric, respiratory, renal, hepatic and cardiac suspected sADRs reported after ivermectin and benzimidazole drug administration across the world, in SSA and RoW.

PRINCIPAL FINDINGS

2041 post-ivermectin or post-benzimidazole suspected sADRs were identified including 667 after ivermectin exposure (208 in SSA and 459 in the RoW). We found an increased reporting for toxidermias, encephalopathies, confusional disorders after ivermectin compared to benzimidazole drug administration. Encephalopathies were not only reported from SSA but also from the RoW (adjusted reporting odds ratios [aROR] 6.30, 95% confidence interval: 2.68-14.8), highlighting the fact these types of sADR occur outside loiasis endemic regions.

CONCLUSION

We described for the first time suspected sADRs associated with ivermectin exposure according to geographical origin. While our results do not put in question ivermectin's excellent safety profile, they show that as for all drugs, appropriate pharmacovigilance for adverse reactions is indicated.

Safety of oral ivermectin during pregnancy: a systematic review and meta-analysis

Background

About 3·7 billion doses of ivermectin have been distributed in mass drug administration (MDA) campaigns globally over the past 30 years. At 10−100 times higher than current human doses, ivermectin is a known teratogen in mammals. During these campaigns with recommended doses, pregnant women might be inadvertently exposed. We therefore aimed to evaluate the existing evidence for serious and non-serious adverse events after ivermectin exposure in pregnant women.

Methods

For this systematic review and meta-analysis, we searched relevant databases and trial registry platforms on July 15, 2018, for randomised controlled trials (RCTs) and observational studies that reported adverse events in pregnant women. We did not use language or date restrictions. Outcomes of interest were spontaneous abortions, stillbirths, congenital anomalies, and neonatal death (serious adverse events), as well as maternal morbidity, preterm births, and low birthweight (adverse events). The risk of bias was assessed using the Newcastle-Ottawa Scale for observational studies and the Cochrane Risk of Bias Tool for RCTs. We did the meta-analysis of observational studies and RCTs separately. The quality of evidence was assessed using the GRADE approach. The study protocol is registered with PROSPERO, protocol CRD42016046914.

Findings

We identified 147 records, of which only five observational studies and one RCT were included for quantitative analysis; these studies were published between 1990 and 2008, and were done in six African countries. 893 women with 899 pregancy outcomes were included, of whom 496 pregnant women (500 pregnancy outcomes) received ivermectin inadvertently during MDA campaigns in the observational studies and 397 pregnant women (399 pregnancy outcomes) purposely received ivermectin as part of the open-label RCT. No study reported neonatal deaths, maternal morbidity, preterm births, or low birthweight. It is unclear whether exposure to ivermectin during pregnancy increases the risk of spontaneous abortions and stillbirths (odds ratio [OR] 1·15 [95% CI 0·75−1·78] with very low certainty of evidence for the four observational studies and 0·62 [0·18−2·14] with very low certainty of evidence for the RCT) or congenital anomalies (OR 1·69 [95% CI 0·83−3·41] with very low certainty of evidence for the five observational studies and 1·10 [0·07−17·65] with very low certainty of evidence for the RCT).

Interpretation

There is insufficient evidence to conclude on the safety profile of ivermectin during pregnancy. Treatment campaigns should focus additional efforts on preventing inadvertent treatment of pregnant women.

Funding

Unitaid.

Mass treatment of onchocerciasis with ivermectin: should people with epilepsy and/or growth-retardation syndromes be excluded?

In many areas of Africa where human onchocerciasis is endemic there are now programmes for mass treatment with ivermectin (Mectizan), to eliminate the disease as a public-health problem. To determine whether those with epilepsy and/or growth-retardation syndromes (GRS) should be excluded from such mass drug administrations, literature searches of the standard biomedical databases were performed for all relevant articles published in English or French before January 2003. Cross-referencing and the retrieving of articles recommended by experts completed the search. The literature review revealed that there is insufficient evidence for an association between onchocerciasis and epilepsy or GRS. Since ivermectin does not normally cross the blood-brain barrier, the drug is unlikely to have direct pro- or anti-convulsive activity. Furthermore, an estimated 1-2 million epileptics in Africa have been treated with ivermectin, in onchocerciasis-control programmes, without any reports of serious adverse events (SAE) to the passive surveillance system for such events. As there are few data on the prevalence of GRS in Africa, it is difficult to estimate the number of GRS cases who have been treated with ivermectin or the incidence of ivermectin-related SAE among such cases. Epileptics should not be excluded from mass treatments with ivermectin unless they are actively seizing or postictal. Although those with GRS associated with chronic wasting, with or without epilepsy, should be excluded, they should be eligible for clinic-based treatment if the diagnosis of onchocerciasis is confirmed and the benefits of treatment are deemed to outweigh any potential risks.

Macrocyclic Lactone Endectocides

The macrocyclic lactone endectocides such as ivermectin, abamectin, selamectin and moxidectin have revolutionized the treatment of parasitic diseases in animals, being active against internal and external parasites. Ivermectin was introduced into veterinary medicine in the 1980s and since that time a number of related compounds have been introduced. In the treatment of internal parasites they complement the use of levamisole and the benzimidazoles, but in recent years they have found utility in treating external insect parasites. These agents show very low levels of toxicity under most circumstances. However, they are neurotoxic particularly in subpopulations of animals with mutations in the MDR1 gene. Toxicity may be also seen during off-label use, possibly because the doses used have been extrapolated from use in other animals. Regardless of these considerations, the macrocyclic lactone endectocides are extremely effective and safe drugs in the treatment of parasitic diseases of animals.

Assessment of loiasis and outcomes of ivermectin masstreatment in Ijebu-North, Nigeria

A total of 286 individuals from 3 selected communities (Areedi-Aje, Ipakodo/Ojokodo, and Ijebu-Igbo) of Ijebu-North, southwestern Nigeria were examined for Loa loa microfilaremia using finger prick blood smear, between December 2008 and March 2009. Rapid assessment procedure for loiasis (RAPLOA) was used to obtain information, from 187 Ijebu-Igbo residents, on adverse reactions experienced from retrospective treatments with ivermectin and history of eye worm. Only 33.9% of the respondents reported having had a history of eye worm while 33.2% had microfilaremia. The demographic factor of gender was not significant determinants of the prevalence (P>0.05) while age was significant (P<0.05). The highest prevalence of eye worm history and microfilaremia were recorded in 61-70 and 15-20 years of age categories, respectively. Ijebu-Igbo had 27.3% eye worm history, 32.1% microfilaremia, and the highest intensity of 140 microfilariae (mf)/ml. Ipakodo area had the highest eye worm history of 54.4% and the highest intensity of 420 mf/ml. Areedi-Aje had the highest occurrence of 45.2% microfilaremia and the highest intensity of 460 mf/ml. Predictably, Areedi-Aje and Ipakodo areas were high risk communities. The low intensity of L. loa infection with an insignificant (2.1%; P>0.05) adverse reactions from 187 subjects involved in the retrospective ivermectin administration confirmed that ivermectin delivery may be considered safe. The community-directed treatment with ivermectin (CDTI) programme was most probably responsible for the low prevalence and intensity.

Prevalences of loiasis in Ondo state, Nigeria, as evaluated by the rapid assessment procedure for loiasis (RAPLOA)

The rapid assessment procedure for loiasis (RAPLOA) was used to assess the prevalences of loiasis among 4800 subjects in 60 villages in Ondo state, south-western Nigeria. Coverages for community-directed treatment with ivermectin (CDTI) were assessed in the same communities, which were located in the Owo, Akure North, Ifedore, Akure South, Ondo East and Ondo West local government areas (LGA). In addition, fingerprick blood samples were collected from 80 individuals in each of six villages (i.e. one village in each LGA investigated) and checked for Loa loa microfilaraemia. Microfilaraemias were only detected in three of the villages where blood samples were collected and then only at low prevalences (1.25%-5.0%) and intensities (267-1600 microfilariae/ml). No serious adverse events were or ever had been related to the CDTI but mild or moderate adverse reactions were quite common, especially in Akure North (55.0%) and Owo (40.2%). A female subject was more likely to report an history of eye worm than a male subject (20.3%-35.7% v. 20.8%-26.5%, according to LGA). Although the subjects aged 41-50 years formed the age-group most likely to report an history of eye worm (32.7%), the highest CDTI coverage was recorded in the subjects aged 61-70 years (54.7%). The results indicated that CDTI had helped to reduce the prevalence and intensity of Loa microfilaraemia and that ivermectin can continue to be used for mass administrations in Ondo state with little risk of serious adverse events.

Refusal to take ivermectin: the associated 'risk' factors in Hoima district, Uganda

Community-directed treatment with ivermectin (CDTI), for the control of onchocerciasis, was launched in Uganda in 1997. In East Africa, as in other endemic areas, the refusal to take the drug reduces treatment coverage and therefore poses a serious threat to attempts to eliminate onchocerciasis as a disease of public-health importance. In early 2003, an attempt was therefore made to determine the factors associated with refusal to take ivermectin during mass treatment in 2002, by interviewing the individuals, from three Ugandan villages with CDTI, who had been eligible to receive ivermectin. The subject's socio-demographic characteristics, history of adverse reactions and participation in CDTI-related activities were explored, as potential 'risk' factors for refusing ivermectin in the treatment round in 2002. When odds ratios (OR) for refusal and their associated 95% confidence intervals (CI) were calculated, the villagers aged 18-35 years were found more likely to have received ivermectin in 2002 than their older counterparts (OR = 0.55; CI = 0.33-0.93). Individuals with an inter-current medical condition were also more likely to have received ivermectin in 2002 than the other villagers (OR = 0.56; CI = 0.32-0.99). Worryingly, the ingestion of ivermectin at any time before the 2002 treatment round was strongly associated with refusal to take ivermectin in that round (OR = 7.72; CI = 2.00-29.81), although there was no evidence that the adverse effects of treatment were significantly reducing coverage.

A randomized, double-blind, controlled trial of the effects of ivermectin at normal and high doses, given annually or three-monthly, against Onchocerca volvulus: ophthalmological results

A three-year randomized, controlled, double-blind trial was conducted in Cameroon to determine whether ivermectin, given at three-monthly intervals and/or at high doses (800 microg/kg), had a greater effect on adult Onchocerca volvulus than standard doses (150 microg/kg annually). As several patients complained of transitory subjective visual problems after treatment, some of them being of an unexpected type, we organized two series of detailed ophthalmological examinations to evaluate whether they were associated with ocular lesions. Analysis showed that these complaints were significantly more frequent in the two groups treated with high doses of ivermectin than in the reference group. In the ophthalmological examinations, the only differences recorded between the groups were a lower prevalence and mean number of microfilariae in the anterior chamber in the groups treated three-monthly, and, at the first examination round, a higher prevalence of early lesions of the iris in the group treated at high doses annually. These findings do not allow us to explain the cause of the transitory ocular complaints, nor why they were more frequent in the groups treated at high doses. However, one may conclude that using doses of ivermectin higher than the standard one should be considered with caution.

Adverse reactions following annual ivermectin treatment of onchocerciasis in Nigeria

OBJECTIVES

This study aims to document and underscore the need to monitor adverse reactions following repeated ivermectin treatment under the current dispensation of the implementation of the Community-directed Treatment with Ivermectin (CDTI) Program. As communities are empowered to distribute ivermectin, monitoring of adverse reactions by health care professionals is important in achieving the onchocerciasis control objectives through mass ivermectin therapy.

METHODS

Eight hundred and ninety subjects from 204 randomly selected households (based on cluster of households) were interviewed using structured questionnaires and in-depth interviews. Responses concerning the adverse effects of ivermectin at the first and sixth rounds were obtained using self-report and treatment records.

RESULTS

Of the 890 individuals, 40.67% presented with adverse reactions at the first round of treatment (TX(1)). This was reduced to 15.06% at the sixth (TX(6)) round of treatment. Pains in joints were more frequently reported at TX(1) and TX(6), 22.7% and 8.5%, respectively.

CONCLUSION

The relatively mild adverse reaction rates observed at TX(1) did not affect future participation in community treatment with ivermectin, due to adequate community mobilization with health education messages. The current CDTI program has a good chance of achieving the onchocerciasis control program's objectives in Shao, Kwara State, Nigeria.

Adverse and beneficial secondary effects of mass treatment with azithromycin to eliminate blindness due to trachoma in Nepal

Mass administration of azithromycin to eliminate blindness due to trachoma has raised concerns regarding the emergence of antimicrobial resistance. During 2000, we compared the antimicrobial resistance of nasopharyngeal pneumococcal isolates recovered from and the prevalence of impetigo, respiratory symptoms, and diarrhea among 458 children in Nepal before and after mass administration of azithromycin. No azithromycin-resistant pneumococci were isolated except from 4.3% of children who had received azithromycin during 2 previous mass treatments (P<.001). There were decreases in the prevalence of impetigo (from 14% to 6% of subjects; adjusted odds ratio [OR], 0.41; 95% confidence interval [CI], 0.21-0.80) and diarrhea (from 32% to 11%; adjusted OR, 0.26; 95% CI, 0.14-0.43) 10 days after azithromycin treatment. The absence of macrolide-resistant isolates after 1 mass treatment with azithromycin is encouraging, although the recovery of azithromycin-resistant isolates after 2 mass treatments suggests the need for resistance monitoring when multiple rounds of antimicrobial treatment are given.

Rheumatic manifestations of parasitic diseases

OBJECTIVES

To consolidate the spectrum and frequency of parasite-related rheumatic syndromes, which have largely been regarded as exceedingly rare by the general medicine, infectious disease, and rheumatology literature.

METHODS

A MEDLINE search was performed for articles on rheumatic syndromes related to parasitic infections published from 1966 through December 2000. Identified articles included clinical and epidemiologic studies describing cases of rheumatic syndromes associated with verified parasitic infection.

RESULTS

Rheumatologic syndromes, including inflammatory arthritis, inflammatory myositis, and vasculitis, have been described among multiple different parasite infections of all parasitic divisions, including Protozoa, Nematoda, and Platyhelminthes. Individual parasitic divisions are often associated with particular rheumatic syndromes, such as reactive arthritis and spondyloarthropathy, inflammatory or infectious myositis, and reactive or parainfectious vasculitis.

CONCLUSIONS AND RELEVANCE

Parasitic infection may underlie the clinical presentation of some rheumatic conditions. Given the continued and growing number of patients at risk for parasitosis by virtue of their country of origin, travel habits, and an immunocompromised state, potential parasitosis must be considered in patients undergoing evaluation for rheumatic complaints.

Successful treatment of scabies with oral ivermectin in Nigeria

Currently, several topical scabicides are available but there is yet no oral or parenteral drug which has been established for the treatment of scabies in Nigeria. Ivermectin which is a modified avermectin, known to be an ectoparasiticidal agent in animals, has been used in adults for systemic parasitosis. In Nigeria, 25% benzyl benzoate is being extensively used for the treatment of scabies in adults. It is effective and readily available. The present study was carried out to evaluate the efficacy and safety of ivermectin in the treatment of patients with scabies at the skin clinic of the University of Nigeria Teaching Hospital, Enugu. Fifty-eight patients with scabies were recruited for the study; 13 (22.4%) were children aged between 5-14 years. Oral ivermectin was given in a single dose of 200 [microg/kg body weight to 29 patients. The remaining 29 patients had to apply 25% benzyl benzoate emulsion. All patients received a full physical and dermatological examination prior to onset of treatment and weekly for 4 weeks. Skin scrapings were taken to confirm the diagnosis of scabies. There was a 93% resolution of pruritus with ivermectin and 48% with benzyl benzoate. No side effects were observed with ivermectin. Our results show that oral ivermectin is a promising, effective and safe alternative in both children and adults of Nigeria when compared to 25% benzyl benzoate topical application.

Drug treatment of tropical parasitic infections: recent achievements and developments

Drug development offers potential solutions to a number of tropical health diseases, although the expense of pharmaceutical research and lack of return on investment has limited the production of new agents. The greatest successes have been through the development of single dose therapy and mass treatment control programmes for a number of diseases. We review some of the current treatment regimens for malaria, intestinal helminth infection, onchocerciasis, filariasis and schistosomiasis, and their use in clinical practice. Geographical spread and emergence of drug resistant parasites have hindered the control of malaria, the most important global parasitic infection. Artemisinin compounds have proved effective antimalarial agents producing rapid reduction of parasite load and can be used in combination treatment regimens to combat multidrug resistance. Intestinal helminth infections are widespread, giving rise to nutritional deficiencies and impaired childhood cognitive development. Pregnant women in developing countries are at increased risk of morbidity. Treatment with a single dose benzimidazole such as albendazole or mebendazole has beneficial effects on morbidity and rates of transmission. Diethylcarbamazine has been used in the treatment of onchocerciasis and human filariasis. A complicated escalating dose regimen over several weeks is associated with systemic and allergic reactions and may require corticosteroid cover. Simplified regimens for mass population treatment with ivermectin have proved useful and been used in combination with single dose albendazole and diethylcarbamazine. The African Programme for Onchocerciasis Control in West and Central Africa has been one of the most successful mass control programmes virtually eliminating new infections by a combination of chemotherapy, education and vector control. Schistosomiasis is of increasing importance as a result of the creation of new snail habitats by agricultural and economic development. Praziquantel has become the most widely available and effective chemotherapy for schistosomiasis. There have been a number of reports of persistent schistosome egg shedding after treatment posing concerns about the emergence of drug resistance. Eflornithine has been successfully used in patients with human trypanosomiasis failing melarsoprol therapy however expense and availability have limited its potential. Mass control treatment programmes have targeted schoolchildren, adolescents and pregnant women. The integration of schistosomiasis, onchocerciasis, filariasis and helminth control programmes has been considered as a cost-effective method of delivering treatment. It is likely that future control will be based on this optimisation and integration of existing regimens, rather than the development of new agents.

Crusted scabies in two immunocompromised children: successful treatment with oral ivermectin

Two immunodeficient children, aged 4 and 12 years, with crusted scabies were successfully treated with a single oral dose of ivermectin (200 micrograms/kg). One child had been diagnosed in infancy with an undefined congenital T cell immunodeficiency and the other with chronic mucocutaneous candidiasis. Both had failed to respond to conventional topical therapy. In view of the excellent therapeutic response and absence of side-effects, ivermectin should be considered in the treatment of recalcitrant crusted scabies in children.

Skin problems in the traveler

Skin lesions are common in travelers and include a mix of mundane dermatologic problems and rare diseases acquired only in remote or tropical regions. The morphology, distribution, and progression of the lesions are useful in assessing possible causes. Early in the evaluation it is important to determine whether the patient might have a process that is rapidly progressive, treatable, or transmissible. In addition to routine laboratory studies, biopsy and serologic tests are often necessary to confirm a specific diagnosis.