Search

V. nana was frequently associated with Schistosoma mansoni and Fasciola spp. This study was conducted to investigate and compare the effects of praziquantel and triclabendazole on V. nana worms, after in vitro exposure to 1 and 2 microg/ml of each of praziquantel or triclabendazole. All the worms were put under observation for 30 minutes. The worm mortality rates were recorded and the topographic tegumental changes were studied by scanning electron microscopy. The results demonstrated that praziquantel showed comparatively superior effect on adult V. nana worms than triclabendazole. The latter still revealed an anthelmintic effect.

Two schedules of anthelmintic oral treatment, using mebendazole powder, were compared in 73 dogs naturally infected with common helminth intestinal parasites. Mebendazole powder was administered to 26 dogs at doses of 22 mg/kg once daily for 3 days and was compared with the same dose given only daily for 5 days into 23 dogs. The 24 other dogs were kept as controls and received a placebo treatment for 5 days. Efficacy results for the 3-day treatment schedule of mebendazole were as follows: Toxocara canis, 100%; Uncinaria stenocephala, 100%; Ancylostoma caninum, 99.4%; Trichuris vulpis, 100%; and Taenia pisiformis, 93.9%. Mebendazole powder given on the 5-day treatment schedule was 100% efficacious against the foregoing parasites. Anthelmintic efficacy against Dipylidium caninum was not detected in either schedule of treatment.

A granulated formulation of fenbendazole was tested in 95 dogs harbouring naturally occurring infections of Toxocara canis, Ancylostoma caninum, Trichuris vulpis, Dipylidium caninum, and Taenia spp and in 19 laboratory-reared Beagle pups experimentally infected with Toxascaris leonina. The drug was administered in moistened dry dog food or in canned dog food. In dosage titration and confirmational studies, using worm counts in naturally infected dogs, the drug was 98%-100% effective at a dosage of 50 mg/kg of body weight/day for 3 days against the commonly occurring nematodes of dogs (ascarids, hookworms, and whipworms) and against Taenia tapeworms. A dosage of 20 mg/kg for 5 days was equally effective against nematodes, but only 73% of the dogs were cleared of Taenia tapeworms. There was no activity at either dosage against Dipylidium tapeworms. Dosages of 100 or 150 mg/kg for a single treatment and 5 or 25 mg/kg daily for 3 days were unsatisfactory with respect to nematodes and tapeworms. Induced infections of T leonina were eliminated from all treated dogs at the dosage and dosing period tested (50 mg/kg/day for 3 days). Fourteen untreated controls expelled 13% of T leonina burdens. It was concluded that granulated fenbendazole is effective in dogs against natural infections of T canis, A caninum, T vulpis, Taenia spp, and experimentally induced infections of T leonina at a dosage of 50 mg/kg of body weight/day for 3 days.

Sheep and goats naturally infested with Stilesia hepatica were treated with either praziquantel (Droncit, Bayer) or oxfendazole (Systamex, Coopers). Praziquantel at 15 mg/kg was 100% effective in 20 sheep; at 7,5 mg/kg 2 out of 20 sheep were still positive. Oxfendazole at 3,5mg/kg was ineffective. In spite of its efficacy the cost of praziquantel prohibits its routine use as an anthelmintic.

The anthelmintic activity of and patient tolerance to albendazole, a broad-spectrum anthelmintic, were studied in a multicenter trial involving 480 patients ranging in age from 2 to 60 years. The patients had single or mixed infections caused by pinworms, roundworms, hookworms, whipworms, threadworms, or tapeworms. The stools were examined by the direct method, and ova were counted by means of the Kato-Katz technique. A Graham-Scotch test was also done in patients infected with Enterobius vermicularis. Most patients received a single 400-mg dose of albendazole; adults were given two tablets, and children were given a 2% suspension. All patients with Hymenolepis nana and about half of those with Taenia infections were treated for three successive days. Patients were carefully evaluated before and after treatment to assess the efficacy and safety of the drug. After a single dose of albendazole, the cure rate was 95.3% in ascariasis, 92.2% in ancylostomiasis, 90.5% in trichuriasis, 64.9% in taeniasis, and 100% in enterobiasis. Among patients receiving 400 mg of albendazole for three days, the cure rate was 63.4% in hymenolepiasis and 86.1% in taeniasis. The drug was well tolerated, and no significant side effects were reported.

Oral administration of mebendazole at a rate of 1 g/kg feed (approximately 50 mg/kg body weight/day) for 14 days killed mature and immature cysticerci of Taenia pisiformis in rabbits, and multiplying tetrathyridia of Mesocestoides corti in mice. Progressive degrees of parasite damage caused by mebendazole treatment could be assessed by histological examination of calcereous corpuscles. A single subcutaneous injection of 10 percent mebendazole in carrier, at a rate of 100 mg/kg body weight, resulted in the death of all M. corti tetrathyridia in mice within 4 weeks, but the drug in saline was slowly mobilized and was relatively ineffective. Neither subcutaneous injections of mebendazole in saline or in carrier could kill cysticerci of T. pisiformis within 5 weeks, but the drug in carrier was effective after several months. Mebendazole in saline was effective when injected intraperitoneally, but adhesions often resulted from this route of administration. Echinococcus granulosus protoscoleces administered to mice by intraperitoneal injection were rapidly encapsulated by host lymphoid cells. The vesiculating protoscoleces were all contained within a fibrous capsule for more than 2 months after infection, but by 4 months almost all had grown free of the host reaction. Treatment of the encapsulated protoscoleces with mebendazole in feed for 14-21 days caused collapse of the outer cysts and death of the germinal membrane of all but the innermost protoscoleces. Six weeks later, however, cysts had regrown from surviving germinal tissue and a further treatment with mebendazole in feed for 14-21 days again did not destroy all germinal cells. Treatment of the 4-month-old scoleces with mebendazole in feed for 14 days caused all cysts to collapse and destroyed practically all E. granulosus germinal tissue. Three subcutaneous injections of mebendazole at fortnightly intervals, of drug in saline at 500 mg/kg body weight, or in carrier at 100 mg/dg body weight, were required in order apparently to kill all secondary cysts of E. granulosus. Host lymphoid cells were not able to traverse the laminated membrane of either untreated or collapsed cysts, and it has been shown that only a small amount of living germinative tissue is required to produce a new E. granulosus cyst. These factors could contribute to the relative ability of E. granulosus cysts to recover from mebendazole treatment, compared with cysticerci or tetrathyridia. The effectiveness of mebendazole thus seemed to depend on the formulation of the drug and its route of administration. Mebendazole is probably the first anthelmintic to have a lethal effect on larval cestodes. When applied orally there do not appear to be any adverse effects due to treatment.

In a series of 5 trials, in which 115 artificially infected calves were used, larval anthelmintic tests were done to assess the activity of oxfendazole at 4, 5 mg/kg against all 3 parasitic stages of 6 species of namatodes. An efficacy of over 98% was demonstrated against the 4th stage larvae (L4), 5th and adult stages of Haemonchus placei, Ostertagia ostertagi, Cooperia pectinata, Bunostomum Phlebotomum and Oesophagostomum radiatum and the 3rd larval stage (L3) of H. placei and C. pectinata. Against the L3 of O. ostertagi, B. phlebotomum and O. radiatum efficacies of 81,7%, 92,4% and 97,3% respectively were shown. Against Dictyocaulus viviparus adult, 5th, L4 and L3 efficacies were recorded of 100%, 96,7%, 95,4% and 89,1% respectively. A test for ovicidal activity confirmed that cattle can be safely moved to clean pasture 8 hours after dosing. Complete removal of strobilia of Moniezia benedeni from 25 naturally infested calves followed a dose rate of oxfendazole at 4,5 mg/kg, but of these each of 4 calves retained one scolex.

Mebendazole (5-benzoyl-2-methoxycarbonylaminobenzimidazole) was highly effective against tetrathydridia of Mesocestoides corti in the peritoneal cavity, liver and in the subcutis of mice when administered orally in the food (450 or 465 ppm) from days 7 or 40/50 post infectionem (p.i.) for 10 or 20 days in total doses of approximately 660-1660 mg/kg body weight (b.w.). All tetrathyridia were killed when treatment began at day 7 p.i., and only some survived when medication was started on days 40/50 p.i. A treatment of 5 days was only partially effective. In experiments with Echinococcus multilocularis laboratory animals were intraperitoneally infected with metacestode tissue transplants. Beginning on days 4-7 p.i. or on day 40 p.i. the animals were treated for 5, 10 or 20/21 days with mebendazole medicated food. In mice a treatment for 10 or 20/21 days with total mebendazole doses of approximately 660-2180 mg/kg b.w. caused an average reduction on metacestode weight of 61-89%. An average reduction between 58 and 84% was achieved in Meriones after a treatment for 20/21 days with total doses of approximately 650/530 mg/kg b.w. However, histological examinations and transplantation experiments revealed that in most of the treated animals metacestode tissue survived and retained its capability for budding. On the other hand, indications for a partial destruction of the parasite tissue were found in some of the treated animals. The oral mebendazole treatment was well tolerated. After intraperitoneal injection of 3 X 150 mg/kg b.w. mebendazole - as applied by Campbell et al. (1975) - all of 36 mice or Meriones died.

The broad-spectrum of activity and safety of mebendazole remain, after 5 years of clinical experience, unique features of this anthelmintic. Through microtubular destruction, mebendazole kills helminths by inhibiting glucose uptake into susceptible parasites. The drug's poor absorption does not appear to affect clinical efficacy except, perhaps, in the treatment of systemic helminth infections. Mebendazole is generally considered the drug of choice for trichuriasis and has therapeutic advantages over other anthelmintics in the treatment of enterobiasis and hookworm infections. Although mebendazole is an effective agent against ascariasis, there are preferable alternatives. Among its nonapproved uses, mebendazole shows great promise in the treatment of capillariasis and hydatid disease. Further investigation is needed to establish its role in the treatment of taeniasis, Hymenolepsis nana, strongyloidiasis, trichinosis, and Dipetalonema perstans. Undoubtedly, mebendazole will find its greatest value in the treatment of patients with multiple helminth infections.

Forty-five commercial-grade Angus calves naturally infected with tapeworms (Moniezia sp) were used in 2 controlled experiments to evaluate the cestocidal efficacy of 3 dosage levels of fenbendazole, methyl-5-(phenylthio) -2-benzimidazolecarbamate. In the 1st trial, 15 calves were divided into 3 groups of 5 each. One group served as nonmedicated controls. Other groups were drenched with fenbendazole at dosage rates of 10 and 15 mg/kg of body weight. Thirty calves used in the 2nd experiment were divided into 3 equal groups. One group served as nonmedicated controls and the other 2 groups were drenched at dosage rates of 7.5 and 10 mg/kg. Calves were necropsied 13 days after treatment. Doses of 10 and 15 mg/kg were 100% efficacious in reducing the number of tapeworm scolices, and a dose of 7.5 mg/kg was 91.7% effective. Signs of toxicosis were not observed in medicated cattle from time of treatment to necropsy.

Anthelmintic trials were carried out to evaluate the efficacy of albendazole against helmi of 2,5 to 3,8 mg/kg administered orally, resulted in a 98,8 to 100% reduction of adult parasites of the genera Haemonchus, Ostertagia, Trichostrongylus, Nematodirus, Gaigeria, Oesophagostomum, Chabertia, Marshallagia and Cooperia. Against the immature stages of these genera, except for Marshallagia and Cooperia, which were not tested, a dose level of 2,5 to 3,8 mg/kg was 83,9-100% effective. Albendazole at 2,5 mg/kg was 99,0% effective against adult stages of Dictyocaulus; its activity at a dose of 3,8 mg/kg against the immature stages of D. filaria was 89,3%. In sheep naturally infested with Moniezia, 100% elimination was obtained at a dose level of 2,5 mg/kg. Dose levels of 3,8 mg/kg and higher were more than 76% effective against adult Fasciola hepatica, while a dose of 4,8 mg/kg was 63% effective against adult Fasciola gigantica.

Fenbendazole at a dosage rate of 15 mg FBZ per kg body mass, was 99,7% effective against adult and 82,5% effective against 4th stage larvae (L4) of Libyostrongylus douglassi. Fenbendazole at the same dose removed scolices and strobila of Houttuynia struthionis from 4 out of 5 treated birds and in the other there were only degenerating scolices, but all 5 untreated control birds were positive for H. struthionis.

Methyl 5(6)-4-2-pyridyl piperazino carbamoyl benzimidazole-2-carbamate (CDRI Comp. 81-470) was tested against various nematode and cestode infections in different experimental and domestic animals. The compound showed 100% effectivity against adult of Ancylostoma ceylanicum (hookworm) in hamsters (6.25 mg/kg p.o. X 1), Nippostrongylus brasiliensis (trichostrongylid) in rats (100 mg/kg p.o. X 3), Hymenolepis nana (cestode) in rats (25 mg/kg p.o. X 1) and Syphacia obvelata (oxyurid) in mice (12.5 mg/kg p.o. X 3). It was also found highly effective against artificial and natural helminth parasites of higher animals. The compound removed all, A. caninum and A. ceylanicum (hookworms) and Toxocara sp. (ascarid) from dogs at a dose of 10 mg/kg p.o. X 3; A. tubaeformis (hookworm) and Toxocara sp. at 25 mg/kg p.o. X 3 and 2.5 mg/kg p.o. X 3 respectively from cats and Ascaridia galli (ascarid) at 10 mg/kg p.o. X 3 from fowl. The compound in doses of 1500 mg/kg by oral route and 1000 mg/kg by i.p. route did not cause any mortality or produce adverse effect in mice. The expanded anthelmintic action and large therapeutic index indicate compound's great anthelmintic potentiality.

The anthelmintic efficacy of cambendazole dosed orally at 20 mg/kg live mass was determined against naturally acquired cestode infestations in lambs. The anthelmintic was completely effective against both Moniezia spp. and Avitellina centripunctata. Difficulties in ascertaining the presence of infestations with the latter species in the living animal are discussed.

This paper presents our experience with mebendazole, a new broad-spectrum anthelmintic, in 91 cases with ascariasis, 71 cases with necatoriasis 54 cases with trichuriasis and 10 cases with T. saginata infection. Various dosage schedules were evaluated. In ascariasis, a single dose of 200 mg was effective in totally clearing the infection in 100 per cent cases. In necatoriasis 200 mg twice daily for four days was found to be the most effective dose. With this dose total eradication of the infection was seen in 92 per cent cases. In trichuriasis, 200 mg twice daily for four days totally eradicated the infection in 90 per cent cases. In T. saginata infection, the drug was totally ineffective. The anthelminitic activity of the drug was demonstrated by the recovery of roundworms, hookworms and whipworms from the stools. The drug was well tolerated. No side effects or toxic effects were seen in any of the cases.

Oxfendazole was tested against Raillietina tetragona in experimentally infected chickens using single oral doses of 20, 10, 7.5, 5, and 2.5 mg/kg body weight. The minimal dose of the drug which produced 100% efficacy against immature worms was 10 mg/kg whereas the same effect on the mature parasite was obtained with 7.5 mg/kg. Doses lower than these significantly reduce worm burdens. The compound appears to be safe for chickens and a dose of 20 mg/kg (twice the recommended dose) produced no untoward clinical reactions.

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.

A number of alkyl 5(6)-(substituted-carbamoyl)- and 5(6)-(disubstituted-carbamoyl)benzimidazole-2-carbamates and related compounds have been synthesized, and their anthelmintic activity against various intestinal helminths of experimental animals have been evaluated. A large percentage of the compounds synthesized showed noteworthy activity against Ancylostoma ceylanicum and at higher doses against Hymenolepsis nana infections. Compared to the alkyl 5(6)-(substituted-carbamoyl)benzimidazole-2-carbamates, the disubstituted carbamoyl analogues were found to exhibit better anthelmintic activity. The most active compound of the series, namely, methyl 5(6)-[(N-2-pyridylpiperazino)carbamoyl]benzimidazole-2-carbamate (90), has been screened against intestinal helminths in higher animals and as a micro- and macrofilaricidal agent. Compound 90 has been identified as a broad-spectrum anthelmintic agent. Compound 90 has been identified as a broad-spectrum anthelmintic in view of its efficacy against A. ceylanicum (hamsters and dogs), H. nana (rats), Nippostrongylus brasiliensis (rats), Syphacia obvelata (mice), A. tubaeformis (cat), Toxocara spp. (cat), and Litomosoides carinii (cotton rat).

Lambs naturally infected with Thysanosoma actinioides and naturally and experimentally infected with Haemonchus contortus were used in a controlled experiment to determine the anthelmintic activity of albendazole as compared with levamisole. The lambs were given 10,000 H contortus larvae 25 to 35 days before treatment, were slaughtered 7 to 9 days after treatment, and were housed on concrete from the time of treatment until slaughter. In lambs given doses of 7.5 mg or 3.8 mg of albendazole/kg or 7.5 mg of levamisole/kg, reductions in numbers of H contortus were 99%, 85%, and 98%, respectively. Reductions in numbers of T actinioides were 98%, 45%, and 0% respectively, as compared with untreated controls.

The efficacy of oxibendazole against gastrointestinal parasites of horses was evaluated by the critical test method. Naturally infected ponies of various ages were given single oral doses of 5, 10, or 15 mg-kg of bodyweight. The drug was highly effective against adult large strongylids (Strongylus vulgaris, S edentatus, S equins), adult small strongylids (especially species of the genera Cylicostephanus, Cylicocyclus, Cyaathostomum, and Triodontophorus), and adult and larval stages of the large pinworm, Oxyuris equi. There was no apparent dose-related differences in efficacy. Oxibendazole was less effective against fourth-stage small strongylid larvae than it was against adults. The drug was inactive against stomach bots (Gasterophilus spp), tapeworms (Anoplocephala magna and A perfoliata), lungworms (Dictyocaulus arnfieldi), abdominal worms )Setaria equina), and mature or immature nematodes in locations other than the lumen of the gastrointestinal tract.