Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Ivermectin”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources
PubMed1991

Effect of early season ivermectin and pyrantel treatments on strongylid infections in young Shetland ponies in The Netherlands.

Two groups of three ponies were used to study the effect of three ivermectin or pyrantel treatments given at intervals of 5 weeks at the beginning of the grazing season. Although each pyrantel treatment resulted in a greater than 95% reduction in faecal egg counts during the first 3 weeks, high pasture larval counts were seen from the beginning of August onwards and substantial cyathostomine burdens were found at necropsy in December. The ivermectin treatments resulted in an even more pronounced reduction in faecal egg output, and the pasture larval counts and cyathostomine burdens at necropsy were considerably lower than in the pyrantel group. The proportion of inhibited early L3 of the cyathostomines was lower in the ivermectin than in the pyrantel group. Faecal egg output of the large strongyles was completely suppressed in the ivermectin group. Nevertheless, Strongylus vulgaris larvae were found in the arteries of all three ponies, possibly as a result of overwintering of infective larvae on pasture. In the pyrantel group, the egg output of Strongylus edentatus and, to a much lesser extent, Strongylus vulgaris, was not completely suppressed.

Animals↗
PubMed1991

Efficacy of some anthelmintics on an ivermectin-resistant strain of Haemonchus contortus in sheep.

Following evidence of reduced efficacy of ivermectin in a field population of Haemonchus contortus in Brazil, this strain of the parasite was submitted to a controlled anthelmintic test. Eighty worm-free lambs were randomly split into two groups of 40. Each lamb in the first group was infected with 5000 third stage larvae (L3) of the ivermectin-resistant strain; the remaining 40 lambs were each infected with 5000 L3 of a H. contortus strain of known susceptibility to the major groups of anthelmintic compounds used in sheep. On Day 28 post-infection, each group was subdivided according to egg counts and at random into four sub-groups of ten lambs, each of which was treated with albendazole (ABZ) at 3.8 mg kg-1, levamisole (LEV) at 7.5 mg kg-1 or ivermectin (IVM) at 0.2 mg kg-1, or was left as untreated control. At slaughter, 7 days later, all the anthelmintics reduced worm burdens in animals infected with the susceptible strain (ABZ 98.9%, LEV and IVM 100%). By contrast, in the lambs infected with the ivermectin-resistant strain, LEV was 99.8% effective, but ABZ reduced worm counts by only 14.7% and IVM by only 10.4%. Interestingly at necropsy on Day 7 post-treatment, the egg counts in the resistant strain treated with ABZ had been reduced by 92.5%, although worm counts were reduced by only 14.7%.(ABSTRACT TRUNCATED AT 250 WORDS)

Albendazole↗
PubMed1991

Efficacy of ivermectin against Parafilaria bovicola and lesion resolution in cattle.

Thirty-two cattle were included in a study to confirm the efficacy of ivermectin administered at 200 micrograms kg-1 against Parafilaria bovicola and to determine the time required for resolution of the lesions caused by the parasite. Four treated and four control animals were slaughtered over 2 days starting 15, 30, 50 or 70 days after treatment. The number, distribution and surface area of carcass lesions, and the weight of tissue trimmed to render the carcasses aesthetically acceptable, were recorded and parasites were recovered from subcutaneous tissues. Significantly (P less than 0.01) fewer worms were recovered from ivermectin-treated cattle slaughtered 50 or 70 days after treatment than from controls. Reductions in the mean number and surface area of lesions, and in the weight of tissue trimmed, were statistically significant (P less than 0.05) for the ivermectin-treated group slaughtered 70 days after treatment and approached significance (P less than 0.1) for the ivermectin group slaughtered 50 days after treatment.

Abattoirs↗
PubMed1992

The efficacy of ivermectin against the eyeworm, Thelazia skrjabini, in experimentally infected cattle.

The anthelmintic efficacy of ivermectin (administered subcutaneously at 200 micrograms kg-1 body weight) was assessed for control of Thelazia skrjabini in experimentally infected calves. Twenty-four uninfected male Holstein calves, 1-2 weeks old, were artificially infected with Thelazia skrjabini by placing 15 third-stage larvae under the third eyelid of calves. The challenge larvae were recovered from naturally infected face flies, Musca autumnalis. The exposed calves were randomly assigned to either an ivermectin treatment group or a control group within pairs ranked by weight. Equal numbers of calves were housed in each of four indoor fly-free rooms. The calves were treated with ivermectin or saline 35 days post-infection, then slaughtered 14 days later to determine eyeworm numbers. All eyes and associated tissues (including the lacrimal glands and ducts) were removed and examined for total number, species and viability of eyeworms. Thelazia skrjabini was found in the control group of calves only. The efficacy of ivermectin against Thelazia skrjabini was thus shown to be 100%.

Animals↗
PubMed1992

Effect of fenbendazole and ivermectin on development of strongylate nematode eggs and larvae in calf feces.

Thirty-nine weaned steer calves (mean weight 284 kg) were maintained under dry-lot conditions and assigned (based on fecal nematode egg count) to one of three treatment groups of 13 animals each as follows: control (no treatment), fenbendazole (5 mg kg-1), and ivermectin (0.2 mg kg-1). Fecal samples were collected 12 h before treatment, at treatment, and 12, 24, 48 and 72 h after treatment for determination of nematode eggs per gram, and (after culture) infective larvae per gram and population distribution. The effect of treatment on egg development was observed in feces collected 12 and 24 h after treatment. There was essentially no difference in efficacy, based on egg counts, of fenbendazole and ivermectin. Egg count was reduced 100% by both anthelmintics at 72 h after treatment. Viability, based on percent of eggs reaching the infective larval stage, of developing stages at 12, 24, and 48 h after fenbendazole treatment was 0.1%, 1.1%, and 0%; after ivermectin treatment the corresponding values were 23.7%, 30.1%, and 28.6%, respectively. Fenbendazole treatment resulted in little or no development of eggs and/or larvae in feces deposited 12 and 24 h after treatment, whereas development proceeded normally (compared with the control group) in ivermectin treated feces. Population distribution of infective larvae was predominantly Haemonchus and Cooperia with some Ostertagia and Oesophagostomum.

Animals↗
PubMed1994

The efficacy of ivermectin (pour-on) against the eyeworms, Thelazia gulosa and Thelazia skrjabini in naturally infected cattle.

Sixteen crossbred beef cattle, 6-8 months of age, were used to determine the efficacy of ivermectin in a pour-on formulation against natural infections of Thelazia spp. Cattle were weighed on Day 0, ranked in descending order by bodyweight and sequentially paired. Within each pair, one animal was randomly assigned to an untreated control group, while the other animal was treated with a pour-on formulation of ivermectin applied topically at 1.0 ml per 10 kg bodyweight to achieve a dosage of 500 mg ivermectin kg-1 body weight. On Day 14 all animals in both treatment groups were slaughtered. The eyes and surrounding tissues were removed and examined for eyeworms. A total of 86 adult worms (74 Thelazia skrjabini and 12 Thelazia gulosa) were recovered from the untreated control animals. T. skrjabini was found in seven, and T. gulosa in three, of the eight untreated control animals. Two T. skrjabini, one from each of two animals, were found on the surface of the eyes of cattle that had received ivermectin treatment. The reduction in the geometric mean number for T. gulosa collected from treated animals was 100% (P > 0.1) relative to controls, and 97.02% (P = 0.0025) for T. skrjabini relative to controls.

Administration, Topical↗
PubMed1993

Effects of ivermectin residues in sheep dung on the development and survival of the bushfly, Musca vetustissima Walker and a scarabaeine dung beetle, Euoniticellus fulvus Goeze.

During produced by sheep for up to 1 week post-treatment (drenching) with ivermectin caused significant mortality to newly emerged larvae of the bushfly Musca vetustissima. Dung from sheep drenched with a mixture of levamisole and oxfendazole also resulted in larval mortality, but here the effect was limited to the first 48 h after treatment. Flies reared through to the adult stage on dung collected up to 32 days post-drenching were tested for evidence of fluctuating asymmetry, which is an indicator of developmental stress. None was found for either drench treatment, although there was evidence that ivermectin residues directly affected wing size. The introduced dung beetle, Euoniticellus fulvus was also found to be sensitive to ivermectin residues in sheep dung. Dung produced during the first day after drenching caused mortality among newly emerged beetles and delayed the reproductive development of survivors. However, beetles in which ovarian development was impaired regained their reproductive capacity following transfer to nontoxic dung. Day 1 dung caused no mortality among sexually mature beetles, although there was a significant reduction in their fecundity. Dung collected from 2 to 10 days post-drenching had no detectable effects on either the survival or reproductive development of adult beetles, regardless of age. Residues in dung collected 1-2 days post-drenching caused 100% mortality in beetle larvae, but by Day 5 there was no evidence of acute toxicity. These findings indicate that insects feeding on the dung of ivermectin-treated sheep display adverse effects similar in range to those reported for cattle dung. However, their duration is much more transient, owing probably to differences in drug formulation and route of administration.

Animals↗
PubMed1995

A method for in vitro determination of the acaricidal effect of ivermectin using Sarcoptes scabiei var. suis as test organism.

An in vitro assay for the acaricidal effect of ivermectin is described. The test is based on the migration ability and survival of Sarcoptes scabiei var. suis mites on the surface of agar gels containing the acaricide. The effect of a given concentration of ivermectin is expressed as an activity index (AI) for the mites, calculated from observed migration and mite survival after 24 h of incubation. In order to allow a concentration-effect curve to be based on true values of the acaricide, a method for the determination of ivermectin in agar gels was developed. Employing this method, ivermectin was demonstrated to be stable in the gels at room temperature for a month, thus allowing storage of gels for later use. The test was found to be accurate, sensitive, easy to carry out and applicable for routine determinations. The lower threshold for acaricidal effect was found to be 50-100 ng ml-1 with the AI showing a reverse linear dependence on the log concentrations above this value.

Animals↗
PubMed1996

The effects of first-season strategic and tactical ivermectin treatments on trichostrongylosis in the first- and second-season grazing.

A 2 year study was conducted to evaluate the effects of first-season strategic or tactical treatments with ivermectin on trichostrongylosis in heifer calves in the first and second-season grazing. Three groups of each eight Holstein-Friesian calves were turned out in early May onto a permanent pasture naturally contaminated with trichostrongyle larvae. Two of these groups were given ivermectin either as strategic treatments (Weeks 3, 8 and 13 after turnout) or as tactical treatments (Weeks 14, 18 and 22 after turnout); the third group served as untreated controls. The strategic ivermectin treatments prevented build-up of high herbage infectivity from mid-summer onwards as shown by low trichostrongyle egg outputs, serum pepsinogen levels and serum antibody responses. In spite of exposure to continuous high larval challenge in late season, the pathogenic effects of worm loads in calves receiving the tactical ivermectin treatment were significantly suppressed. The performance of the strategically treated calves tended to be higher than that of the tactically treated calves in the first-season grazing; yet, there was no statistical difference. During the following summer, all three groups were grazed in a single herd together with a new group of eight first-season calves. No anthelmintic treatments were given to any animals during the season. From late August until the end of the season all animals were given weekly experimental challenge infections. Following the challenge infections, the first-season calves developed clinical parasitic gastroenteritis, whereas the second-season heifers showed no symptoms. At post-mortem it was found that worm burdens mainly consisted of early fourth-stage larvae (L4) of Ostertagia ostertagi (> 97%). Fewer adult worms were recovered from the untreated animals than from the treated ones. However, serum anti-parasite IgG1 responses and post-mortem worm counts suggested that the untreated heifers harboured markedly fewer adult O. ostertagi than the previously treated ones, indicating a higher level of immunity against adult worms. However, this difference did not have any clinical impact in this experiment.

Animals↗
PubMed1996

Efficacies of different doses of ivermectin against male, female and L4 Oesophagostomum dentatum in pigs.

Efficacies of ivermectin against larval stages and adult males and females of Oesophagostomum dentatum were investigated in two slaughter assays. In Experiment A, 20 pigs were each infected with 6000 third-stage larvae on Day 0 and Day 24. Pigs were ivermectin treated on Day 28 at dose rates of 0, 75, 150, and 300 micrograms kg-1 bodyweight (bw) and slaughtered 6 days after treatment. In Experiment B, 20 pigs each received 6000 third-stage larvae and were treated 35 days after infection at dose rates of 0, 150, 300 and 600 micrograms kg-1 bw. Pigs were slaughtered 14 days after treatment. In Experiment A, the adult worm burden was reduced by 69.1% at a dose rate of 300 micrograms kg-1 bw and the larval burden was reduced by 68.7 and 90.9% at 150 and 300 micrograms kg-1 bw, respectively. In Experiment B, the adult worm burden was reduced by 88.8, 96.2 and 99.6% at dose rates of 150, 300 and 600 micrograms kg-1 bw, respectively. In the control group of Experiment A, the mean proportion of females among adults worms was 57.6%, but this decreased to 19.7% after ivermectin treatment at 300 micrograms kg-1 bw. In Experiment B, at 300 micrograms kg-1 bw, this proportion was reduced from 46.0% to 0.8%. The fecundity of female worms was reduced at dose rates of 150 and 300 micrograms kg-1 bw in Experiment A, but not in Experiment B. It is concluded that in O. dentatum, ivermectin not only reduces the egg output of female worms, but also is more effective against female than male worms.

Animals↗
PubMed1986

DIDS, an anion transport blocker, modulates ivermectin-induced enhancement of benzodiazepine receptor binding in rat brain.

Ivermectin enhancement of [3H]diazepam binding was abolished by pretreatment of membranes with 0.05% Triton X-100, whereas GABA-induced enhancement was not changed after this treatment. Ivermectin enhancement was neither affected by picrotoxinin nor dependent on the chloride ion. 4,4'-Diisothiocyano-2,2'-disulfonic acid stilbene (DIDS) dose-dependently reduced [3H]diazepam binding enhanced by 10(-6) M ivermectin, without affecting the basal specific binding. The effects of DIDS were derived from reduction of increased binding affinity of benzodiazepine receptors by ivermectin, but were not dependent on chloride ion in the assay medium. DIDS inhibited GABA- and pentobarbital- but not chloride ion-induced enhancement of [3H]diazepam binding.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1985

Human ivermectin exposure.

Ivermectin is a veterinary antiparasitic medication for domestic animals. Two cases of human exposure to veterinary preparations of ivermectin are reported. Patient number one accidentally self-injected ivermectin and developed nausea, pallor, and transient pain and numbness in the affected extremity. Patient number two, a 4-year-old child, ingested an unknown amount of the paste preparation and remained asymptomatic. As ivermectin is being used with increasing frequency in veterinary medicine, more human exposures may be anticipated.

Adult↗
PubMed1993

Interaction of the neurotoxic pesticides ivermectin and lindane with the enteric GABAA receptor-ionophore complex in the guinea-pig.

In isolated segments of guinea-pig small intestine, gamma-aminobutyric acid (GABA) (3-300 microM), the GABAA receptor agonist 3-aminopropane sulphonic acid (3-APS) (3-300 microM) and ivermectin (1-300 microM) caused concentration-dependent nerve-mediated cholinergic contractions sensitive to tetrodotoxin (1 microM) and hyoscine (1 microM). The EC50 values were 30.2 +/- 4.3, 24.6 +/- 3.1 and 4.8 +/- 0.6 microM, respectively. Picrotoxinin (10 microM), an allosteric blocker of the Cl- channel associated with GABAA receptors, non-competitively antagonized the contractile response caused by each agonist. Like picrotoxinin, lindane (10, 30 microM) caused a dose-related shift to the right of the concentration-response curve to GABA, 3-APS and ivermectin with depression of the maximum response. SR 95531 (3 microM), a competitive antagonist of GABAA receptors, caused a parallel dextral shift of the concentration-response curve to ivermectin with an apparent single point pA2 value of 6.5. Our results suggest that ivermectin and lindane, two neurotoxic pesticides interfering with central GABAErgic transmission, exert agonist and non-competitive antagonist properties at the enteric GABAA receptor-ionophore complex. This peripheral complex can thus be considered as an additional target for the action of both these compounds.

Animals↗
PubMed2006

Toxicity and gross pathology of ivermectin bath treatment in sea bream Sparus aurata, L.

The isopod parasite Ceratothoa oestroides becomes hard to eradicate in intensive fish rearing systems and in addition to causing weight loss in adult fish it causes mortalities in larval and juveniles stages of sea bass and sea bream. Faced with the fast emergence of this infection in Adriatic finfish facilities, an effective compound had to be tested for bath treatment. Ivermectin was chosen for this purpose on the basis of extensive practice in northern European countries which used ivermectin administered in food with good results in treatment of Lepeophtheirus sp. and Caligus sp. infections. For determination of toxicity of ivermectin, a short-term toxicity bioassay on 40-day-old sea bream, Sparus aurata, L., was conducted, following FAO and UNEP procedures for methodology in aquatic toxicity trials. Median survival time, slope functions, and 95% confidence limits for ivermectin showed moderate toxicity in sea bream, with first 100% mortalities during 96h at the concentration of 1.8 mg/L.

Animals↗
PubMed2004

Bioactivity of a peptide derived from acetylcholinesterase: involvement of an ivermectin-sensitive site on the alpha 7 nicotinic receptor.

A peptide fragment of 14 amino acids, derived from the C-terminus of acetylcholinesterase (AChE), might underlie the now well-established noncholinergic effects of the enzyme. This peptide is bioactive in a variety of systems including acute (brain slices) and chronic (organotypic culture) preparations of hippocampus, a pivotal area in Alzheimer's disease (AD); invariably, the action of the peptide is mediated specifically via an as yet unknown receptor. In this study, the allosteric alpha 7 agent, ivermectin (IVM), had a modest inhibitory effect, whilst that of the peptide was significantly more marked. However, ivermectin rendered ineffective the toxicity of high doses of the peptide, that is, when the two were co-applied, only the smaller effects of ivermectin were seen. Ivermectin, therefore, is presumably acting at a site that is identical to, or at least strongly interactive with, the normal binding site for AChE-peptide. This observation could have important implications for eventual therapeutic targeting of the action of AChE-peptide, in neurodegeneration.

Acetylcholinesterase↗
PubMed2004

Adverse systemic reactions to treatment of onchocerciasis with ivermectin at normal and high doses given annually or three-monthly.

In Cameroon, a 3-year randomized, double-blind controlled trial was conducted to determine if ivermectin, given at 3-monthly intervals and/or at high doses (800 microg/kg), had a greater effect on adult Onchocerca volvulus than standard annual doses of 150 microg/kg. Adverse reactions were recorded and analysed in a logistic regression model with random effects to assess the influence of the dose and rhythm of treatment on their occurrence. After the first dose, 3-monthly treatment was associated with a clearly reduced risk of reactions, especially oedematous swellings, pruritus and back-pain. Oedematous swellings and subjective ocular troubles were found to be associated with high doses of ivermectin. These results reinforce former parasitological conclusions that it would be desirable to evaluate the feasibility and effects on transmission of large-scale 3-monthly treatments with standard doses of ivermectin for onchocerciasis control. Owing to the unexpected ocular reactions, the use of high doses to counteract any future resistance of O. volvulus to ivermectin should be considered with caution.

Adolescent↗
PubMed2005

Assessments of pharmacokinetic drug interactions and tolerability of albendazole, praziquantel and ivermectin combinations.

The pharmacokinetic interactions and tolerability of albendazole, praziquantel and ivermectin combinations were assessed in 23 healthy Thai volunteers (12 males and 11 females). The study was an open, randomised, three-way crossover design in which each subject attended the study on three separate occasions (Phases I, II and III), of 4 d or 8 d each, with at least 1 or 2 weeks (but not longer than 2 months) between each phase. All subjects received the three study drug regimens as follows: regimen I, oral praziquantel (40 mg/kg body weight); regimen II, oral ivermectin (200 microg/kg body weight) given concurrently with an oral dose of albendazole (400 mg); and regimen III, oral ivermectin given concurrently with albendazole and praziquantel. All treatment regimens showed acceptable tolerability profiles. The incidence of overall drug-related adverse events was significantly higher following regimens I (12/23) and III (7/23) compared with that following regimen II (0/23). Six statistically significant changes in the pharmacokinetic parameters of albendazole sulphoxide (Cmax, AUC0-infinity, Vz/F, CL/F), praziquantel (Vz/F) and ivermectin (AUC0-infinity) were observed when the three drugs were given concurrently. However, based on US Food and Drug Administration criteria, these changes were not considered of clinical relevance.

Adult↗
PubMed2004

Effect of the antiparasitic drugs fenbendazole and ivermectin on the soil nematode Pristionchus maupasi.

Pristionchus maupasi, a soil nematode, was used to elucidate the potential ecotoxic effect of the two anthelmintics fenbendazole and ivermectin in cattle dung. The population growth of P. maupasi was greater in faeces from cattle harbouring active Panacur- or Ivomec-boli, which are releasing fenbendazole and ivermectin to the rumen, respectively, compared to the growth in control faeces. In dose-response experiments it could be shown that the pure chemical compound of fenbendazole was increasingly nematocidal to P. maupasi in concentrations from 10 to 20 microg/g faeces (ww, i.e. wet weight) and the pure compound of ivermectin was effective above 3 microg/g faeces (ww). The results indicate that neither fenbendazole nor ivermectin have any acute toxic effect on P. maupasi in naturally excreted concentrations of the pure drugs, together with their metabolites in faeces from bolus-treated cattle. Both drugs are excreted in concentrations that are non-toxic to P. maupasi.

Animals↗