Activity of ivermectin against canine intestinal helminths

The anthelmintic activity of ivermectin was tested in 98 dogs against adult ascarids (Toxocara canis, Toxascaris leonina), hookworms (Ancylostoma caninum, A braziliense), and whipworms (Trichuris vulpis), and against experimentally induced infections (4th-stage larvae) of T canis and A caninum. Dosage levels tested were single subcutaneous injections of 50, 100, 200, or 400 micrograms/kg of body weight with appropriate vehicle-treated controls. A minimum of 4 (usually 5) dogs were tested with each parasite and dosage level. The lowest dosage level, 50 micrograms/kg, and all higher dosage levels expelled greater than 99% of the adult forms of both species of hookworms and intestinal larval forms of A caninum, as determined by worm counts at necropsy. A dosage level of 100 micrograms/kg was required to expel greater than 99% of whipworms and 200 micrograms/kg was necessary to expel adult (91%) and larval (97%) stages of T canis. Ivermectin was only marginally effective (34.2%, 46.2%, 69.2%, and 53.8%) against Toxascaris leonina at 50, 100, 200, and 400 micrograms/kg, respectively, and had no effect against occasional infections with the tapeworms, Dipylidium caninum (14 dogs) and Taenia spp (3 dogs).

Anthelmintic activity of closantel against Ancylostoma caninum in dogs

The efficacy and minimum therapeutic dose of closantel, an injectable salicylanilide anthelmintic, was evaluated on adult Ancylostoma caninum. Doses of 7.5 and 10 mg/kg had a marked anthelmintic effect on adult stages, removing 99 and 98%, respectively. A second experiment tested the efficacy of closantel against hypobiotic larval stages of A. caninum. A dose of 20 mg/kg did not affect the abundance of arrested hookworm larvae or prevent their subsequent development, but it may have inhibited their full maturation as adult worms so that patent, intestinal infections did not occur. Small numbers of adults were recovered from treated dogs at 29, 43, and 57 days post-treatment, but no eggs were passed in their feces. These studies bear on the practical problem of control of hookworms in dogs.

Effect of febantel against Ancylostoma caninum and Trichuris vulpis infections in dogs

Febantel was administered as a 3.4% paste to 45 dogs infected with 1 or more nematode species, which included Ancylostoma caninum and Trichuris vulpis. Dosage levels of 5, 10, or 15 mg/kg of body weight daily for 3 consecutive days for a total of 15, 30, or 45 mg/kg were administered. At 15 mg/kg, all dogs were completely cleared of all nematode and cestode infections, including A caninum, T vulpis, Uncinaria stenocephala, Toxocara canis, Toxascaris leonina, Taenia sp, and Dipylidium caninum, except for 1 Physaloptera sp adult. The 2 other dosage levels produced somewhat lower efficacy, with the 5 mg/kg being the least effective. The paste appeared palatable to the dogs and there were no apparent adverse effects.

Albendazole: a new broad spectrum anthelmintic. Double-blind multicenter clinical trial

A new anthelmintic drug, albendazole, has been tested in a multicenter double-blind placebo controlled study in 392 patients from France and West Africa in children and adults with single or mixed infections caused by roundworms, hookworms, whipworms, threadworms and tapeworms. All patients were closely observed before and after treatment for clinical side effects, hematological or clinical blood chemical changes. Fecal samples obtained before, and 7 days and 21 days after treatment were examined using a concentration technic (Ritchie), a coproculture (Harada-Mori) and an egg count (Kato). Following a single dose of 400 mg in adults, cure rates of 96% in ascaridiasis, 96% in ancylostomiasis caused by dose of 400 mg in adults, cure rates of 96% in ascaridiasis, 96% in ancylostomiasis caused by Ancylostoma duodenale, 90% in ancylostomiasis caused by Necator americanus and 76% in trichuriasis were recorded. About 48% of the patients infected by Strongyloides stercoralis were cured following administration of 400 mg per day for 3 consecutive days. The efficacy of half of the adult dose (200 mg) was much lower in children. None of the patients who received placebo were cured. The drug did not produce any significant side effects and approximately the same numbers were reported in the albendazole and the placebo groups. No variations of the hematology and clinical blood chemistry values were recorded.

[Treatment of intestinal nematode infections with albendazole. Preliminary results (author's transl)]

A randomized double-blind study, in order to evaluate effectiveness and tolerance of albendazole, was carried out in 186 african subjects presenting intestinal nematode infections in Mali and Senegal. The drug, well tolerated, given as a single dose of 0.4 g (adolescents and adults) or 0.2 g (children) is curative in more than 90% for ascariasis. For ancylostomiasis and trichuriasis, the effectiveness is less satisfactory in children, probably due to insufficient dosage in this age group.

Anthelmintic activity of mebendazole against induced and naturally occurring helminth infections in cats

A formulation of mebendazole was used to determine the optimal dosage level against induced and/or naturally occurring infections of Toxocara cati, Ancylostoma tubaeforme, and Taenia taeniaeformis in cats. Amounts of 11 mg/kg of body weight/day or 22 mg/kg/day were given for 2, 3, or 4 days. Feces were collected for 7 days and were examined for expelled parasites. Cats were necropsied to recover retained parasites. A regimen of 22 mg/kg/day for 3 days was determined to be optimal with efficacies of 100%, 99%, and 50% against T cati, A tubaeforme, and Taenia taeniaeformis, respectively.

[Albendazole. Evaluation of tolerance and efficacy in oxyuriasis, trichocephaliasis, ankylostomiasis, ascaridiasis, anguilluliasis]

Albendazole was given to some men for the first time. 131 patients (43 children) received different dosages, without clinical intolerance. Biological parameters were normal. Each study was made in two parts: - determination of the good dosage, - administration in a double-blind study (except for Strongyloides Stercoralis). Albendazole has a good efficiency against Enterobius Vermicularis, Trichuris trichiura, Ascaris lumbricoides and Necator americanus. Strongyloides Stercoralis seems to be killed by this drug, but complementary studies will be necessary.

Tropical infections contracted in Papua New Guinea and imported into Western Australia

Diseases contracted in Papua New Guinea (PNG) and observed in Western Australia (WA) have comprised malaria, amoebiasis, ancylostomiasis, filariasis and leprosy. This small series of cases demonstrates the prolongation of incubation periods of malaria following chemoprophylaxis, the spread of chloroquine-resistant strains of Plasmodium falciparum (both to Western and Eastern regions of PNG), the ineffectiveness of chloroquine against Entamoeba histolytica in the intestine and the value of oral penicillin as a prophylactic for filarial lymphangitis.

Levamisole compared to mebendazole in the treatment of Ancylostoma duodenale in Egypt

Ancylostoma duodenale in 74 patients and Ascaris lumbricoides in 41 were treated with a single 150 mg dose of levamisole, a single 300 mg dose of mebendazole or the standard three-day regimen of 200 mg mebendazole daily. Levamisole cured all of the 25 hookworm patients and all of the seven Ascaris carriers to whom it was given and is recommended as the drug of choice in Egypt.

Evaluation of granulated fenbendazole (22.2%) against induced and naturally occurring helminth infections in cats

A granulated formulation of 22.2% fenbendazole was tested for anthelmintic activity against helminths in cats. The drug was administered in 20 g of canned food on each of 3 days at a dosage of 50 mg/kg of body weight/day. Of 31 young adult cats harboring naturally occurring infections of Toxocara cati, 16 were treated and 15 served as controls. There was 100% clearance of ascarids from all treated cats. Among controls, 18% of the ascarid burden was expelled naturally. Thirty additional cats were acclimated for 2 months prior to infecting them experimentally with Aelurostrongylus abstrusus, Taenia taeniaeformis, and Ancylosatoma tubaeforme. Treatment caused a transitory reduction in the number of lungworm larvae. Histopathologically, cells of developing eggs and of a majority of 1st-stage larvae in lungs of treated cats had evidence of marked degeneration and necrosis, whereas the same stage of larvae in lungs of control cats were normal. Although the number of lung lesions in treated cats was approximately half the number found in controls, there was no significant (P > 0.05) indication that this was due to treatment. Fenbendazole was effective against induced infections of A tubaeforme and Taen taeniaeformis. Greater than 99.9% of hookworms were expelled from 16 treated cats as compared with a 2% natural expulsion from 15 controls. Of 24 cats that developed patent infections of Taen taeniaeformis, 12 were treated and cleared of this parasite, whereas 9 of 12 controls continued to harbor 1 to 10 tapeworms at the time of necropsy. Fenbendazole at a dosage of 50 mg/kg/day x 3 days appeared to be an effective anthelmintic against the common ascarid, hookworm, and tapeworm of cats. Its activity against lungworms was inconclusive at the dosage used, but the data suggest the need for investigating its activity against this parasite at higher dosages, for longer periods of treatment, or both.

The efficacy of amidantel, a new anthelmintic, on hookworms and ascarids in dogs

Amidantel is a new anthelmintic from a new chemical class with an interesting anthelmintic spectrum. In dogs amidantel is highly effective in a single oral dose of 25 mg/kg against both hookworm species, Ancylostoma caninum and Unicinaria stenocephala. In Toxascaris leonina infected dogs a complete cure rate was achieved with a single oral dose of 50 mg/kg. Similar results were obtained with 8 mg/kg administered three times per day. The most sensitive parasite to amidantel was found to be Toxocara canis with a 100 per cent cure rate after a single oral treatment with 10 mg/kg. In preliminary trials amidantel was also effective against hookworms and ascarids after subcutaneous administration. All hookworms and almost all of the ascarids were eliminated with the faeces within 2 days after treatment. Amidantel was tolerated in all dosages tested by all the dogs without any symptoms.

Use of fenbendazole suspension (10%) against experimental infections of Toxocara canis and Ancylostoma caninum in beagle pups

Eleven nematode-free Beagle pups were inoculated with Ancylostoma caninum and Toxocara canis; infection became patent 13 and 35 days later, respectively. Eight pups were treated with fenbendazole oral suspension (10%) at a dosage of 50 mg/kg of body weight/day for 3 days. The remaining three animals were unmedicated controls. The drug was effective in reducing both ascarid and hookworm burdens, and there was marked improvement in the clinical condition of treated pups as compared with unmedicated control pups. Natural expulsion of worms in control animals was 53% for ascarids and 2% for hookworms. Drug-related toxicosis was not observed in any of the medicated animals. It was concluded that fenbendazole oral suspension (10%) at the 50-mg/kg dosage is easily administered and is an effective drug for reducing nematode burdens in experimentally infected pups.

The efficacy of anthelmintics against third stage larvae of Ancylostoma caninum in Mastomys natalensis

Investigations have been carried out on the multimammate rat (Mastomys natalensis), orally infected with 1000 third stage larvae of Ancylostoma caninum per animal, to evaluate the larvicidal efficacy of anthelmintics in this paratenic host. The oral or subcutaneous administration of 19 anthelmintics and filaricides revealed good activity for levamisole, cambendazole, and mebendazole against 15-day-old Ancylostoma larvae which were located in the muscular tissue. Similarly, good results were obtained with levamisole and cambendazole against the migrating third stage larvae, by treatment two to six days after infection. The benzimidazole derivatives, thiabendazole, oxibendazole, parbendazole, and fenbendazole showed marked activity only at high dosage rates. The anthelmintics methyridine, amoscanate, pyrantel tartrate, morantel tartrate; the microfilaricidal organophosphates dichlorvos, fenthion, and haloxon; as well as the micro- or macrofilaricidal drugs diethylcarbamazine, nitrofurantoin, nifurtimox, suramin sodium, and thiacetarsamide sodium failed to show larvicidal activity even in high dosages. The average larval recovery rate after oral infection with 1000 third stage larvae, in untreated control animals, was 14.85%.

Comparative trial on the therapeutic effectiveness of the new anthelmintic drug: ciclobendazole

In a double-blind study in Cameroon the vermicidal effect of Ciclobendazole, a new Benzimidazole derivative, was evaluated and compared to Mebendazole. Ciclobendazole and Mebendazole were equally effective in the treatment of Ascaris and Hookworm infestations. An increase in the dosis of Ciclobendazole from 600 mg to 1200 mg did not lead to an improvement in the effectiveness. When treating trichuriasis significantly better results were achieved with Mebendazole (p = 0.01). Both drugs were tolerated equally well. Side effects, such as vomiting and diarrhoea, only occurred in a small percentage of cases.

[Therapeutic trials of a new anti-helminthic in Colombian Amazonia: flubendazole]

After a coprologic survey made at Araracuara, a village in colombian Amazonia showing high prevalences of nematodosis, 83 villages (including 55 children below twelve) were given Flubendazole during three consecutive days. The total dose was 600 mg. for children below 12, and 900 mg. for adults. The product efficiency was 88% for Trichuris, 82% for Hookworm, 77% for Ascaris and 43% for Strongyloïdes. The tolerance was excellent in all cases, in spite of heavy parasital infection. The Flubendazole's effect seems to be particularly interesting by its polyvalency.

Efficacy of seven anthelmintics against Ancylostoma ceylanicum in the golden hamster, Mesocricetus auratus

In an experimental patent infection of Ancylostoma ceylanicum in golden hamsters the efficacy of seven anthelmintics was tested; bephenium hydroxynaphthoate, tetramisole, tetrachlorethylene, phenylene 1,4-diisothiocyanate, thiabendazole, parbendazole and mebendazole were studied. Mebendazole was the most effective, with parbendazole, phenylene 1,4-diisothiocyanate, thiabendazole and bephenium hydroxynaphthoate also satisfactory. Tetrachlorethylene and tetramisole were the least effective in our screen.

Comparative single/dose treatment of hookworm and roundworm infections with levamisole, pyrantel and bephenium*

One-hundred and forty-five farmers aged 7-45 years who were infected with Ancylostoma duodenale and/or ascaris were treated with a single dose of levamisole, pyrantel, or bephenium. The percentage cure rates were ascaris 100 per cent ahd hookworm 93 per cent for levamisole; ascaris 90 per cent and hookworm 78 per cent for pyrantel; and ascaris 73 per cent and hookworm 81 per cent for bephenium. The 3 drugs were well tolerated. The opinions and assertions contained herein are the private ones of the authors and are not to be construed as official or as reflecting the views of the Department of the Navy or The Egyptian Ministry of Healty.

Comparative studies on the evaluation of the effect of new anthelminthics on various intestinal helminthiasis in Iran. Effects of anthelminthics on intestinal helminthiasis

The effect of pyrantel pamoate, levamisole, mebendazole, thiabendazole and bephenium hydroxynaphthoate on various intestinal helminths were evaluated among the inhabitants of four villages in the Dezful area southwest of Iran. A total number of 328 persons, all infected simultaneously with Ascaris and hookworm (Ancylostoma duodenale) and 49.2% with Trichostrongylus spp., were randomly divided into six groups. One group was kept as the control and the other five were each treated with one compound. Follow-up examinations showed that all of the drugs used were highly effective on Ascaris, and the differences in the cure rate were not statistically significant except for bephenium hydroxynaphthoate which showed a lower cure rate. For hookworm, cure rates of 100, 90, and 85% were observed with levamisole, pyrantel pamoate and bephenium hydroxynaphthoate, respectively. Cure rates observed with mebendazole and thiabendazole were 35 and 51%, respectively. For Trichostrongylus, the highest cure rate was achieved with levamisole, followed by thiabendazole and mebendazole. While the percentage of people showing side-effects was rather low for all drugs, thiabendazole and bephenium hydroxynaphthoate produced a higher, and levamisole a lower, percentage of side effects.

Uredofos: anthelmintic activity against nematodes and cestodes in dogs with naturally occurring infections

A new broad-spectrum anthelmintic, uredofos, was tested in 146 dogs by single and multiple oral dosing. Single doses of 100 and 50 (but not 25) mg/kg were totally effective in removing Dipylidium caninum and Taenia spp from 46 dogs with infections of tapeworms. Among groups of 15 to 20 dogs, the average percentage efficacies against Toxocara canis for single soese of 100, 50, and 25 mg/kg were 98, 96, and 81%, respectively. The average percentage of efficacies against hookworm (Ancylostoma caninum) were greater than 96% in dogs treated with single doses of 100, 50, or 25 mg/kg and were 100% in the 35 dogs given 2 or 3 treatments (24-hour intervals) at dose levels of either 25 or 50 mg/kg. The whipworm, Trichuris vulpis, was not efficaciously eliminated by single doses of 25, 50, and 100 mg/kg (av percentage of efficacies of 30, 35, and 71%, respectively). Efficacy against T vulpis markedly improved when 2 doses were given at a 24-hour interval (av percentage of efficacies were 89% at dose level of 25 mg/kg and 99% at dose level of 50 mg/kg). At either dose (25 or 50 mg/kg), 3 daily treatments were no more efficacious against whipworms than were 2 doses. There was no evidence of drug toxicosis in any dogs tested. It was concluded that uredofos is highly effective against canine tapeworms, ascarids, and hookworms when given as a single dose of 50 mg/kg and against whipworm when given at dose level of 50 mg/kg/day for 2 days.

Anthelmintic activity of diuredosan in dogs experimentally infected with Ancylostoma caninum and Trichuris vulpis

The efficacy of diuredosan was determined in dogs experimentally infected with Ancylostoma caninum and Trichuris vulpis. Diuredosan at dosages of 25, 50, and 100 mg/kg was 99% effective against A caninum. Efficacies against T vulpis were 88, 85, and 94% at dosages of 25, 50, and 100 mg/kg, respectively.

[Vulvitis due to ancylostoma duodenale (author's transl)]

There is reported about a case of vulvitis, which was resistant to usual forms of therapy. Infections as such of Candida or of Trichomonas as well as diabetes could be excluded. But there could be proved an incidence of Ancylostoma duodenale, which is nowadays more often to be observed. Adequate therapy was successful.

Treatment of ankylostomiasis with levamisole

The authors communicate their experience in the treatment of ankylostomiase with levamisole; with a dose of 2.5 mg/kg body weight they achieved a positive result in two-thirds of the cases in a series of 119 without any toxic side effects.

[Anthihelminthic activity of pyrantel pamoate administered in mass treatment of an isolated population of the South Pacific]

A stool examination survey on the Wuvulu island population in Papua-New Guinea let be shown off the high incidence of two helminthiasis, ascariasis and trichocephalosis (75-4 0/0 and 70 0/0 of the tested subjects) compared to the low incidence of ankylostomiasis (7 0/0). With pyrantel pamoate administered in one oral dose of 10 mg by kg of weight, results are excellent in ascariasis with 97-7 0/0 success. The efficiency is only partial in ankylostomiasis with that small dose. It is quite well tolerated and may be used in mass treatment and, taking into account the special characteristics of that small and far away island, an attempt to eradicate ascariasis through systematic reiterated treatments is being carried out.

Drug evaluation of pyrantel pamoate against Ancylostoma, Toxocara, and Toxascaris in eleven dogs

Eleven dogs dosed at approximately the recommended rate of 1.029 mg of pyrantel pamoate/kg of body weight were used. The efficacy against Ancylostoma in the 11 dogs was 99% (av; min-max, 94-99%). In 4 dogs with both Toxocara and Ancylostoma, average efficacy against Toxocara was 96%, and in 5 dogs with both Toxoscaris and Ancylostoma, efficacy against Toxascaris was 93%. Only 2 dogs of the 11 were infected with the 3 species; the average efficacy was 90%. There appeared to be no activity against the Trichuris found in one dog and the Dipylidium found in another. Treated dogs did not vomit or have other noticeable ill effects.