Suspected adverse reactions to oral administration of a praziquantel-pyrantel combination in captive cheetahs (Acinonyx jubatus)

OBJECTIVE To characterize adverse reactions to oral administration of a combination of praziquantel and pyrantel embonate or pyrantel pamoate, with or without oxantel embonate, in captive cheetahs (Acinonyx jubatus). DESIGN Retrospective case series and case-control study. ANIMALS 16 captive cheetahs with signs of adverse reaction to oral administration of praziquantel and pyrantel, with or without oxantel embonate (affected group), and 27 cheetahs without such reactions (unaffected group), all from 3 independent facilities. PROCEDURES Medical records and postmortem findings for affected cheetahs were reviewed and compared with those of unaffected animals. Anthelmintic doses administered, age, and sex of cheetahs were compared between groups. RESULTS 3 reactions in affected cheetahs were fatal, whereas the remainder ranged from mild to severe. Postmortem examination failed to reveal any disease processes or conditions to explain the deaths. No differences in anthelmintic dose were identified between affected and unaffected cheetahs for all facilities combined, and no correlation existed between dose and reaction severity. No association with sex was detected, but affected cheetahs were significantly younger than unaffected cheetahs. This difference was not significant after controlling for facility. CONCLUSIONS AND CLINICAL RELEVANCE Cheetahs were concluded to have had an adverse reaction to the praziquantel-pyrantel combination because of temporal proximity of onset of clinical signs to dose administration, similarity of signs to those reported for toxicosis in other species for these drugs, and a lack of other disease process or environmental explanatory factors. A highly cautious approach to the use of this drug combination is recommended for cheetahs.

Field evaluation of the efficacy and the safety of a combination of oxantel/pyrantel/praziquantel in the treatment of naturally acquired gastrointestinal nematode and/or cestode infestations in dogs in Europe

In five multicentre field trials, the efficacy and safety of a combination of oxantel/pyrantel/praziquantel (Dolpac), Vetoquinol SA) in the treatment of naturally acquired gastrointestinal nematode and/or cestode infestation in dogs was evaluated in northern and southern Europe. Forty-eight investigators from France, Belgium, Germany, Italy and Spain enrolled 329 dogs to be treated with the tested combination; 235 of these dogs complied with the inclusion criteria of the protocol and had a tested helminth identified on Day 0. A pooled analysis was performed on each of the following helminth species: Toxocara canis, Ancylostoma caninum, Toxascaris leonina, Trichuris vulpis, Uncinaria stenocephala, Taenia spp. and Dipylidium caninum, which were isolated on Day 0. The main efficacy criterion was the egg per gram (epg) percent reduction of the nematodes and the absence of proglottids and or eggs for the cestodes. After treatment, dogs were examined on Day 7, Day 14 and Day 21. The efficacy of the combination against Toxocara canis was 99.1%, 98.8% and 98.9% on Day 7, Day 14 and Day 21, respectively. At the same occasions the efficacy was, respectively, 99.2%, 99.2% and 99.3% against Ancylostoma caninum, 97.3%, 97.2% and 98.4% against Trichuris vulpis, 98.4%, 98.8% and 98.8% against Uncinaria stenocephala, 98.9%, 99.5% and 99.9% against Toxascaris leonina, 97.1%, 100% and 100% against Dipylidium caninum and 100% against Taenia spp.

Efficacy of long-term monthly administration of ivermectin on the progress of naturally acquired heartworm infections in dogs

This study was designed to evaluate the efficacy of prolonged monthly ivermectin treatment against Dirofilaria immitis in client-owned dogs with naturally acquired infections and to clinically monitor the animal's response to the slow killing of heartworms, with death of the worms distributed over a period of up to 2 years. A total of 17 male and female dogs of different breeds and ages were used. Prior to treatment, all of the dogs tested positive for heartworm antigen (Ag) and all but two had microfilariae (mf). The dogs were randomly allocated to one group of seven dogs which received a commercial formulation of ivermectin (minimum, 6 mcg IVM/kg) plus pyrantel (minimum, 5 mg PP/kg) (Heartgard Plus Chewables, Merial, Ltd.), another group of seven dogs which received a commercial formulation of IVM (min, 6 mcg/kg) (Heartgard Chewables, Merial Ltd.), and a group of three dogs which served as an untreated controls. All dogs were evaluated prior to initiation of treatment and thereafter at 3- to 5-month-intervals for mf, Ag, and radiographic and echocardiographic findings. All of the 17 dogs, with the exception of two dogs in the IVM group, had circulating mf of D. immitis prior to the 1st monthly dose, and a few also had mf of Dirofilaria repens. After 4 monthly doses, only one dog in the IVM/PP group and two dogs in the IVM group had a patent heartworm infection, and no heartworm mf were seen in the 14 treated dogs thereafter. After 10 monthly doses, the number of Ag-positive dogs in both of the treated groups decreased gradually. Efficacy, based on the reduction in number of Ag-positive dogs, was similar for the IVM/PP and IVM groups, with overall efficacy scores for the 14 dogs of 21, 21, 43, and 71% after 10, 14, 19, and 24 monthly doses, respectively. Two of the seven dogs treated with IVM/PP, one of the seven treated with IVM, and two of the three untreated controls showed echocardiographic evidence of a parasitic burden prior to treatment, and all of these scores had decreased by the end of the study. Only one dog (IVM/PP group) had a cardiovascular pattern of heartworm disease by echocardiography prior to treatment, but this dog's score increased to two and the scores of two additional dogs increased from zero to two (IVM group) or three (IVM/PP group) by the end of the study. Only 1 (IVM/PP group) of the 17 dogs showed a pulmonary pattern of heartworm disease by radiography prior to treatment, but this dog's score increased to three by the end of the study. The radiographic scores of two additional dogs in the treated groups increased from zero to three (IVM/PP) or two (IVM) by the end of the study. Thus, monthly administration of IVM to dogs with clinical, radiographic or echocardiographic evidence of heartworm disease is ill-advised and such treatment of even the asymptomatic dog should be done only with much caution and frequent monitoring by the veterinarian.

A comparative trial of oxantel-pyrantel and mebendazole in multiple helminth infection in school children

In a pilot study in 17 children, oxantel-pyrantel as one single dose of 10 to 20mg/kg of each, gave good results in ascariasis but poor cure rates in both trichuriasis and necatoriasis. However in the latter groups the infection was extremely heavy. In a controlled trial in 51 children, using oxantel-pyrantel at the same dose, but given daily for 3 consecutive days, or mebendazole 100mg twice daily for 3 days, the drugs gave similar response rates. Both gave 100% cure rates, as assessed by the absence of ova by both Beaver and brine-flotation techniques, in Ascaris lumbricoides infection. The percentage cures and egg reduction rates were 66.7 and 94.5 in trichuriasis and 53 and 93.6 in necatoriasis respectively. Those for mebendazole were 52 and 91.2 in trichuriasis and 37.5 and 89.7 in necatoriasis. Oxante-pyrantel treatment was associated with more cures, and a marginally greater reduction in ovum excretion than mebendazole but the differences were not statistically significant. No side-effects were seen with either treatment.

Treatment of multiple intestinal helminthiasis with oxantel and pyrantel

32 elementary school children were treated for multiple intestinal helminthiasis (ascariasis, trichuriasis and hookworm infections) with a combination of the pamoate salts of oxantel and pyrantel in a dose of 15 to 20mg/kg body weight of each in 1 daily dose for 3 consecutive days. The cure rate for ascariasis was 96.7%, and 84.4% for both trichuriasis and hookworm infections. 68.7% were completely cured of all 3 helminths. However, among those not completely cured, only 1 species of the previous 3 infecting helminths was present after treatment and then with a very marked reduction in egg count.

Antiminth (pyrantel pamoate)

A new broad-spectrum anthelminthic, anti minth (pyrantel pamoate), has been evaluated in 1,506 patients, mainly children. Single doses of 5/mg/lb/body weight (base activity) showed high overall efficacy against Enterobius vermicularis (97.2%) and Ascaris lumbricoides (97.5%). In tropical locations, in patients with multiple in festataons, single doses of 10 mg/lb/day for three consecutive days achieved a cure rate of 86.4 per cent with Necator americanus. With a smaller number of patients, a lower dosage of 5 mg/lb/day for three consecutive days was also effective (90.7%). At recommended doses (5 mg/lb/day), Antiminth (pyrantel pamoate) was well tolerated and free of adverse effects upon hematologic, renal, and hepatic function. There was not the troublesome staining seen with certain other anthelminthics. The safety profile was further substantiated by clinical experience with doses in excess of 5 mg/lb/body weight, at times carried on for several weeks.