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PubMed1991

Comparison of high dose ivermectin and diethylcarbamazine for activity against bancroftian filariasis in Haiti.

This three-phase study was designed to compare high dose ivermectin with a standard diethylcarbamazine (DEC) regimen for patient tolerability, potential to kill adult filaria, and duration of microfilarial suppression in 30 Haitian subjects with Wuchereria bancrofti microfilaremia. All were first given a 1-mg oral dose of ivermectin (phase 1) to reduce microfilaria densities. Participants were randomized into three groups: Group 1 received DEC (6mg/kg per day for 12 days), Group 2 received 200 mcg/kg of ivermectin, and Group 3 received 400 mcg/kg of ivermectin (200 mcg/kg per day for 2 days). All drug regimens were well tolerated with few adverse reactions. Most reactions occurred during phase I and consisted primarily of headache, fever, and myalgia. At the end of phase 1, 27 of 30 (90%) patients were microfilaria negative. During phase 2, four of the six men receiving DEC developed scrotal reactions suggesting killing adult worms; no such reactions were noted in 10 men receiving ivermectin (p less than 0.05). At one-year follow up (phase 3), all treatment groups had less than 10% return to pretreatment microfilaria levels. The mean percent of baseline microfilaria counts were for Group 1, 0.9% (range 0-5%); Group 2, 8.2% (range 0-31%); and Group 3, 3.8% (range 0-25%). Seven individuals in Group 1 were microfilaria-negative, while only one and three individuals were microfilaria-negative in Groups 2 and 3, respectively. These results suggest that DEC causes more damage to the adult worms and greater reduction in microfilaria densities than ivermectin, but that high doses of ivermectin may suppress microfilaremia in lymphatic filariasis for periods much longer than previously reported.

Adolescent↗
PubMed1993

Comparison of single-dose diethylcarbamazine and ivermectin for treatment of bancroftian filariasis in Papua New Guinea.

This double-blind study compared the clinical safety and parasitologic efficacy of single-dose regimens of diethylcarbamazine (DEC) and ivermectin for treatment of bancroftian filariasis in Papua New Guinea. Five groups of 10 men each with mean levels of parasitemia ranging from 2,985 to 5,185 microfilariae (mf)/ml were given DEC (6 mg/kg of body weight one time or 1 mg/kg, then 6 mg/kg four days later) or ivermectin (220 micrograms/kg; 20 micrograms/kg, then 200 micrograms/kg four days later or 20 micrograms/kg, then 400 micrograms/kg four days later). No significant side effects (e.g., acute adenolymphangitis, fever lasting more than eight hours, hypotension) were observed in any of the five treatment groups. The magnitude of reduction in microfilaremia was greater (P < 0.01) for the three ivermectin groups versus the two DEC groups in the first 30 days after drug administration (mf levels < 1% of pretreatment values versus 22.6-41.5%, respectively). At 90 and 180 days, mf levels continued to decrease in the DEC groups whereas they increased in the ivermectin groups given a total dose of 220 micrograms/kg. Eighteen months after drug administration, individuals given DEC or 420 micrograms/kg of ivermectin had the greatest degree of reduction in microfilaremia (86-90% compared with the pretreatment values). Decreases in parasite antigenemia measured by enzyme-linked immunosorbent assay for a secreted 200-kD adult worm antigen were greatest for the single-dose DEC group (39.7% decrease relative to the pretreatment level versus 7.8-15.7% for the ivermectin groups). These results indicate that single-dose DEC and ivermectin are well-tolerated by Wuchereria bancrofti-infected individuals with high levels of microfilaremia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Ivermectin treatment of onchocercal skin lesions: observations from a placebo-controlled, double-blind trial in Malawi.

To determine effects of ivermectin on skin lesions of onchocerciasis, a placebo-controlled, double-blind trial was carried out in the Thyolo highlands of Malawi involving 70 persons over a 32-month period. Assessment was made using both a clinical numeric grading system and sequential photographs. Among both ivermectin and placebo recipients, there was a significant reduction in both the severity and extent of papular skin lesions. Persons with edematous or lichenified skin lesions of onchocerciasis who received ivermectin showed significantly more improvement than those receiving placebo. Twelve months after the placebo group received ivermectin, their skin lesions were similar to those of the ivermectin group. Changes were most evident for those persons with more severe skin disease in both the ivermectin and placebo groups. Annual ivermectin treatment for onchocercal skin lesions is probably inadequate, and treatment three or four times a year may be required, although the optimum regimen has not been established.

Adolescent↗
PubMed2003

A comparison of the efficacy of single doses of albendazole, ivermectin, and diethylcarbamazine alone or in combinations against Ascaris and Trichuris spp.

OBJECTIVE: To determine the efficacy of single doses of albendazole, ivermectin and diethylcarbamazine, and of the combinations albendazole + ivermectin and albendazole + diethylcarbamazine against common intestinal helminthiases caused by Ascaris and Trichuris spp. METHODS: In a randomized, placebo-controlled trial, infected children were randomly assigned to treatment with albendazole + placebo, ivermectin + placebo, diethylcarbamazine + placebo, albendazole + ivermectin, or albendazole + diethylcarbamazine. The Kato-Katz method was used for qualitative and quantitative parasitological diagnosis. The chi2 test was used to determine the significance of cure rates, repeated measures analysis of variance for the comparison of mean log egg counts, the Newman-Keuls procedure for multiple comparison tests, and logistic regression for the comparison of infection rates at days 180 and 360 after treatment. FINDINGS: Albendazole, ivermectin and the drug combinations gave significantly higher cure and egg reduction rates for ascariasis than diethylcarbamazine. For trichuriasis, albendazole + ivermectin gave significantly higher cure and egg reduction rates than the other treatments: the infection rates were lower 180 and 360 days after treatment. CONCLUSION: Because of the superiority of albendazole + ivermectin against both lymphatic filariasis and trichuriasis, this combination appears to be a suitable tool for the integrated or combined control of both public health problems.

Adolescent↗
PubMed2003

Some observations on the pharmacological properties of ivermectin during treatment of a mite infestation in mice.

Ivermectin has become one of the most widely used drugs for the treatment of parasitic infections in laboratory rodents. Despite its wide popularity, little has been published regarding its pharmacokinetic properties in mice. We made use of a routine mite control treatment in a conventional animal unit to gain some knowledge of these properties. Numerous inbred, outbred, and transgenic lines of mice were being treated with ivermectin in the drinking water (32 mg/L) for a chronic Myocoptes infestation. A sample of mice from different cages and rooms was culled at various time intervals to check levels of ivermectin in blood. In addition, cellophane tape impressions of fur were obtained from mice undergoing treatment to monitor the effectiveness of ivermectin in controlling the mite infestation. Results showed that ivermectin levels rose sharply in the serum of treated mice and gradually fell once treatment was discontinued. Maximum levels detected at the end of a 10-day period of treatment were 90 ng/ml. Once treatment was discontinued, serum levels of the drug were undetectable after 7 days. In addition, treatment with ivermectin proved very effective in reducing parasite burdens in the colony. Results were in line with known pharmacological properties of ivermectin in other species. Nevertheless, it was worth noting that serum levels can vary markedly depending on various factors, something to be taken into account when considering treatment of mice, especially transgenics.

Administration, Oral↗
PubMed1991

The treatment of microfilaremia due to Wuchereria bancrofti var. pacifica: ivermectin versus diethylcarbamazine.

In October 1989, a controlled, double-blind parallel group trial was implemented to compare both efficacy and tolerability of single doses of ivermectin and diethylcarbamazine (DEC). Fifty eight apparently healthy Wuchereria bancrofti carriers were hospitalized and randomly allocated to treatment with ivermectin 100 mcg/kg, DEC 3 or 6 mg/kg. Six months later, half of those initially treated with ivermectin 100 mcg/kg and DEC 3 mg/kg were given a second similar dose while the rest were given a placebo. After initial treatment, clearance of microfilaremia was complete in 22 of the 23 carriers treated with ivermectin and in one only of the 35 treated with DEC. Adjusted geometric mean microfilaremia was significantly lower (p less than 0.01) in carriers treated with ivermectin than in those treated with DEC at one, but neither at 3 (p = 0.26) nor at 6 months (p = 0.63). The comparison of adjusted geometric mean microfilaremia per group indicated that (i) regarding either ivermectin 100 mcg/kg or DEC 3 mg/kg, 2 successive doses resulted in higher efficacy than one annual dose and (ii) efficacy of 2 successive doses of ivermectin 100 mcg/kg or DEC 3 mg/kg were not significantly different. During the 3 days following initial treatment, adverse reactions were observed in 80% of the treated carriers of whom 14% suffered a grade 3 reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Effects of repeated Strongylus vulgaris inoculations and concurrent ivermectin treatments on mesenteric arterial lesions in pony foals.

Eight of 10 pony foals reared under helminth-free conditions were inoculated PO with 50 Strongylus vulgaris infective larvae/week for 4 weeks, at which time 1 foal died of acute verminous arteritis. Inoculation of 7 remaining foals continued at 2-week intervals for 20 weeks. Of the 7 foals, 3 were treated with ivermectin (0.2 mg/kg of body weight) in an oral paste formulation at experiment weeks 8, 16, 24; 4 foals were not treated. Two foals were not inoculated or treated and served as controls. After the first ivermectin treatment, ivermectin-treated foals had fewer days (12 +/- 2.9) with rectal temperatures greater than 38.6 C than did nontreated foals (23.3 +/- 3.8). Mean baseline rectal temperatures were 38 +/- 0.2 C. Adverse clinical reactions to ivermectin treatment were not observed in foals. Foals were euthanatized and necropsied 3 weeks after the last ivermectin treatment (week 24). Ivermectin was effective in reducing S vulgaris arterial larval and intestinal adult parasite numbers by 100% in 3 treated foals. Strongylus vulgaris arterial larvae and/or adults were recovered from all 4 nontreated inoculated foals. One nontreated inoculated foal lacked arterial larvae or active arterial lesions, indicating that protective resistance had developed in this individual. Marked gross and histopathologic lesions typical of chronic S vulgaris infection were observed in the 3 nontreated inoculated foals with arterial larvae. Repeated killing of intra-arterial S vulgaris fourth-stage larvae in ivermectin-treated foals did not exacerbate lesions associated with verminous arteritis or induce unique lesions associated with repeated destruction of arterial larvae.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1989

Efficacy of ivermectin in the treatment of induced Parascaris equorum infection in pony foals.

Eighteen pony foals inoculated with 1,500 +/- 109 infective Parascaris equorum eggs were given 0.02 ml of ivermectin vehicle (liquid)/kg of body weight, PO, (control); 0.2 mg of ivermectin paste/kg, PO; or 0.2 mg ivermectin liquid/kg, PO, on postinoculation day (PID) 28. Foals were euthanatized on PID 42, and the small intestinal contents were examined for P equorum larvae. The mean number of fourth-stage P equorum larvae in foals treated with ivermectin paste and liquid were 3.5 and 6, respectively. Significantly (P less than 0.01) higher mean numbers of larvae (1,250) were detected in foals treated with ivermectin vehicle. Larvae recovered from foals treated with ivermectin vehicle were of significantly (P less than 0.002) longer mean length than those from foals treated with ivermectin paste or liquid. Gross examination of lungs and liver revealed similar pathologic changes from the migration of P equorum in all foals. Adverse reaction to treatment was not observed.

Animals↗
PubMed1989

Efficacy of ivermectin against experimental and natural infections of Gasterophilus spp in ponies.

Antiparasitic efficacy of ivermectin against migrating Gasterophilus intestinalis was evaluated in 36 treated and 24 nontreated (n = 12) or vehicle-treated (n = 12) ponies experimentally and naturally infected with G intestinalis and naturally infected with G nasalis. Each pony was experimentally infected with 500 G intestinalis 1st instars in 2 divided doses on days -14 and -7 before treatment. On day 0, ivermectin was administered at the rate of 200 micrograms/kg of body weight by IV (n = 12) or IM injection (n = 12) or given as an oral paste (n = 12). Ponies were euthanatized and necropsied 21 days after treatment. In each nontreated or vehicle-treated pony, late 1st-, 1st- to 2nd- instar molt, and early 2nd-instars of G intestinalis were found in the mouth, and 2nd- and 3rd instars of G intestinalis and 3rd instars of G nasalis were found in the stomach. Bots were not found in any ivermectin-treated pony and, thus, ivermectin was 100% effective against oral and gastric stages. Adverse reactions were not observed in ponies given ivermectin by IM injection or orally, but 1 pony given the vehicle IV and 1 pony given ivermectin (in the vehicle) IV had an anaphylactic reaction, resulting in death of the ivermectin-treated pony. It was speculated that the adverse reaction was caused by histamines released in response to vehicle components given by IV injection.

Animals↗
PubMed1989

The chemotherapy of onchocerciasis. XIII. Studies with ivermectin in onchocerciasis patients in northern Ghana, a region with long lasting vector control.

One hundred and ninety eight patients with moderate to heavy infections with Onchocerca volvulus were randomly assigned to receive single doses of 100, 150 or 200 mcg/kg of ivermectin or matching placebo capsules. Detailed systemic, ocular and parasitological examinations were carried out at intervals over a period of one year. Nodules were excised twelve months after treatment to evaluate the effect of the treatment with ivermectin in adult O. volvulus. The three ivermectin-treated groups produced massive reductions in skin microfilariae (over 97%) with low levels being maintained over one year. The 150 and 200 mcg/kg doses were however superior to the 100 mcg/kg dose in achieving a greater reduction in skin microfilarial counts initially and in maintaining significant lower levels throughout the period of observation. There was no difference between the 150 and 200 mcg/kg doses at anytime. The three ivermectin doses were equally effective in the clearance of ocular microfilariae. The proportion of dead adult worms was very high in all treatment groups, which is effected by the successful ten years lasting vector control in northern Ghana. In spite of this superannuation of the worm population, an impact of the treatment with ivermectin on the reproductivity of the parasite could be shown. Systemic total clinical reaction was mild and was similar in the ivermectin treated groups. However, severe symptomatic postural hypotension (SSPH) was limited to patients treated with 150 or 200 mcg/kg of ivermectin. Ocular reactions were mild in all patients and no ocular deficiency occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Ivermectin effect on microfilariae of Onchocerca volvulus after a single oral dose in humans.

Ivermectin is a broad spectrum anti-helminthic agent which is currently being tested for use in human onchocerciasis. Its activity is believed to result from its effect on GABA-mediated neurotransmission. We examined the effects of ivermectin on motility of microfilariae of O. volvulus following administration to humans. When ivermectin was given in dosages of 100, 150 and 200 mcg/kg on day 1 there was a clear reduction in motility of microfilariae obtained on day 3 when compared to microfilariae from the placebo group. The mean motility scores in microfilariae from ivermectin recipients were 3.1, 2.3, and 2.2 at 0, 12, and 24 hours of incubation compared to 3.3, 2.9, and 2.5, respectively, in microfilariae from placebo recipients (p less than 0.003, p less than 0.005, and p less than 0.012, respectively). Examination of the effect according to dose suggested a dose-response relationship. Microfilariae in the anterior chamber of the eye 2 days after a single oral dose of ivermectin showed abnormal and reduced winding and coiling. Microfilariae in 50% of ivermectin recipients showed abnormal motility compared to no such effects in subjects examined concurrently who received oral DEC, DEC lotion or placebo. These observations indicate that ivermectin has an effect on motility of microfilariae of O. volvulus following administration to humans.

Animals↗
PubMed1984

The microfilaricidal activity of ivermectin in vitro and in vivo.

Ivermectin has been tested against the microfilariae of Onchocerca lienalis, Brugia pahangi and Dirofilaria immitis in vitro and in vivo. All in vitro tests were performed on larvae incubated for 48 hours at 37 degrees C in Hepes buffered medium 199 containing 20% serum, benzylpenicillin and streptomycin. In vivo tests were performed on larvae in female BALB/C mice dosed with ivermectin, 5 mg/kg, orally. The microfilariae of B. pahangi in vitro were insensitive to ivermectin at concentrations to 30 ng/ml. In vivo, an 87% reduction in the level of microfilaraemia was obtained by 24 hours after drugging but no reduction was observed in the numbers of peritoneal microfilariae. O. lienalis microfilariae in vitro were killed by ivermectin at 3 ng/ml and the larvae of this species within the subcutaneous and cutaneous tissues of the mouse were also eliminated by ivermectin at 5 mg/kg. D. immitis larvae within the bloodstream of the mouse were also sensitive to ivermectin at the dosage employed but were unaffected by ivermectin in vitro at concentrations up to 30 ng/ml.

Animals↗
PubMed1995

Ivermectin for treatment of generalized demodicosis in dogs.

OBJECTIVE: To evaluate the efficacy of daily administration of ivermectin in the treatment of dogs with amitraz-resistant generalized demodicosis. DESIGN: Prospective, clinical trial. ANIMALS: Twelve privately owned dogs with juvenile-onset or adult-onset generalized demodicosis that had failed to respond to biweekly or weekly applications of 0.025% amitraz solution. PROCEDURE: All dogs were treated with undiluted ivermectin at a dosage of 0.6 mg/kg of body weight, PO, every 24 hours. There was no other parasiticidal agent given topically or systemically. A physical examination and multiple skin scrapings were performed every 2 to 4 weeks while dogs were receiving ivermectin. Skin scrapings were performed at approximately the same sites at every examination. After no mites were seen, treatment was continued for at least 2 more weeks and then stopped. Dogs were reexamined, and skin scrapings were repeated if any skin lesions developed. For dogs that remained clinically normal, follow-up information was obtained by telephone. Dogs that were free of clinical signs of demodicosis 12 months after ivermectin administration was discontinued were considered cured. RESULTS: Ten of 12 dogs were cured. Median duration of treatment for these dogs was 10 weeks (range, 6 weeks to 5 months). Two dogs were failures, relapsing 10 months and 11.5 months after treatment was stopped. One of these dogs was successfully treated with a second course of ivermectin. Mild ivermectin toxicosis developed in 1 dog after 6 weeks of treatment; side effects resolved shortly after the treatment was stopped. CLINICAL IMPLICATIONS: Daily use of ivermectin, at a dosage of 0.6 mg/kg, PO, was found to be effective in the treatment of generalized demodicosis in dogs.

Animals↗
PubMedDate not supplied

[The use of ivermectin in the control of onchocerciasis].

Onchocerciasis is an infection with the nematode Onchocerca volvulus. The main clinical symptoms are caused by the microfilariae. They include ocular lesions leading to blindness. Onchocerciasis is widely distributed in Africa from the Sahara to the southern tip, and is also found in some areas of South and Central America. Ivermectin was shown to be an effective treatment in the early 1980's, and is safe and better tolerated than diethylcarbamazine. We report the results of ivermectin treatment of onchocerciasis, and various features of the control obtained by large-scale ivermectin treatment programs. In large-scale programs, ivermectin (150 micrograms/kg) is administered once a year. This dose paralyses the microfilariae, such that they are carried away by the lymph to the lymph nodes where they are destroyed. This dose thereby reduces the load of microfilaria by 90%. The effects of a dose of ivermectin last about two or three years, and the lesions in the anterior segment of the eye can be cured or substantially reduced. Regular treatment prevents severe lesions of the posterior segment of the eye. The effects of repeated treatment on lesions of the retina are currently under investigation. Frequent doses of ivermectin prevent the development of embryo parasites in the females, and reduces the number of adults by attrition. Large-scale treatment programs reduce the transmission of the parasite by its vectors. There are several problems impeding large-scale treatment programs. Choosing patients for priority treatment requires expensive and sometimes aggressive methods of diagnosis. Thus new techniques for the identification of communities in which onchocerciasis is a serious public health problem are required. The choice of strategies for distribution, to optimize the cost, benefit ratio and feasibility, remain controversial. Wide distribution by mobile teams is effective, but expensive. Active distribution by trained community distributors is a cheaper potential alternative. Clinic-based or passive distribution requires the population to present to be able to obtain ivermectin. Thus, although cheap, this approach is generally poorly effective. A further complication is the clearly defined criteria on which these methods should be evaluated.

Africa↗
PubMed1994

Residual nematocidal effectiveness of ivermectin in cattle.

We assessed the duration of ivermectin persistence by measuring posttreatment nematocidal effectiveness; topical and injectable formulations of ivermectin were evaluated. Thirty-five nematode-free calves were randomly allocated to 1 of 5 treatment groups (7 calves/group). The treatment (Trt) group designations were: Trt 1, nonmedicated; Trt 2, injectable ivermectin administered at the rate of 0.2 mg/kg of body weight on day 0; Trt 3, injectable ivermectin administered at the aforementioned rate, but on day 7; Trt 4, topically administered ivermectin at the rate of 0.5 mg/kg on day 0; and Trt 5, topically administered ivermectin at the aforementioned rate, but on day 7. All calves were subsequently given infective larvae of Haemonchus, Cooperia, Trichostrongylus, and Oesophagostomum spp on day 21. One week later, each calf was additionally administered infective larvae of Dictyocaulus and Ostertagia spp. Trial calves were euthanatized on trial days 49 to 52 for nematode quantitation. On the basis of geometric mean comparisons, total nematode burdens were reduced from control group counts by 98.9 and 86.3% for calves treated on days 7 and 0 with injectable formulations, respectively, and 97.2 and 64.7% for calves treated on days 7 and 0 with pour-on formulations, respectively. Trichostrongylus colubriformis infections were most refractory to the persistent activity of ivermectin, with H placei also proving to be persistence limiting. All treatments were easily administered, and adverse behavioral or tissue reactions were not observed.

Administration, Topical↗
PubMed1997

Impact of annual dosing with ivermectin on progression of onchocercal visual field loss.

Reported are the results of a randomized, double-masked, placebo-controlled trial of annual ivermectin dosing in 34 rural communities, Kaduna State, northern Nigeria, where guinea savanna onchocerciasis is mesoendemic. A total of 939 individuals underwent Friedmann field analysis at the first examination and saw at least 19 spots in at least one eye. Of these, 636 (68%) completed a subsequent Friedmann field analysis 2-3 years later. The adjusted incidence rate ratio for the ivermectin group versus the placebo group was 0.64 (95% confidence interval (CI): 0.42-0.98). There was some evidence that the impact of ivermectin was greatest among those who had received one dose of ivermectin. The majority of the deteriorations occurred in eyes that gave evidence of optic atrophy at the first examination. An analysis restricted to individuals with optic atrophy at baseline indicated a reduction of 45% in the incidence of visual field deterioration in the ivermectin group (95% CI: 8-67%). Previous findings have shown that ivermectin has an impact on the incidence of optic atrophy. Our results indicate, for the first time, that ivermectin has a substantial impact on the progression of visual field loss among those with pre-existing optic atrophy.

Adolescent↗
PubMed2006

Assessment of microfilarial loads in the skin of onchocerciasis patients after treatment with different regimens of doxycycline plus ivermectin.

BACKGROUND: Infection with the filarial nematode Onchocerca volvulus can lead to severe dermatitis, visual impairment, and ultimately blindness. Since the currently used drug, ivermectin does not have macrofilaricidal or strong permanent sterilising effects on the adult worm, more effective drugs are needed to complement the use of ivermectin alone. Wolbachia endosymbiotic bacteria in filariae have emerged as a new target for treatment with antibiotics which can lead to long -term sterilization of the adult female filariae. METHODS: In the Central Region of Ghana, 60 patients were recruited, allocated into four groups and treated with 200 mg doxycycline per day for 2 weeks, 4 weeks, 6 weeks respectively. Untreated patients served as controls. Some of the treated patients and the untreated controls were given 150 microg/kg ivermectin 8 months after the start of doxycycline treatment. RESULTS: A follow up study 18 months post treatment showed that when using doxycycline alone there was a significant reduction of microfilarial (mf) loads in patients treated for either 4 or 6 weeks. However, there was no significant difference between the untreated controls and those given the 2 weeks regimen. Although no significant difference was demonstrated between the 4 and 6 weeks regimens, there was a trend observed, in that, microfilarial reduction appeared to have been greater following the 6 weeks regimen. Twelve months after ivermectin (i.e. 20 months after doxycycline) treatment, 8 out of 11 ivermectin-alone treated patients were mf-positive. In contrast, 1 out of the 7 patients treated for 4 weeks with doxycycline and none of the 4 patients treated for 6 weeks doxycycline (who were available for re-examination) were mf-positive after the combined treatment of doxycycline plus ivermectin treatment. CONCLUSION: Treatment of onchocerciasis with doxycycline for 4 weeks is effective. Nonetheless, mf reduction appeared to be greater in the 6 weeks regimen. It is recommended that until further studies are carried out i.e. 4 weeks treatment with doxycycline is proven equivalent to the 6 weeks, selected groups of onchocerciasis patients should be treated for 6 weeks with doxycycline. As discussed earlier, this treatment should be accompanied by two doses of ivermectin.

Journal Article↗
PubMedDate not supplied

Detection of unwanted residues of ivermectin in bovine milk by dissociation-enhanced lanthanide fluoroimmunoassay.

Avermectins are frequently used to control parasitic infestations in many animal species. Previous studies have shown the long-term persistence of unwanted residues of these drugs in animal tissues and fluids. An immunoassay screening test for the detection and quantification of ivermectin residues in bovine milk has been developed. After an extensive extraction procedure, milk samples were applied to a competitive dissociation-enhanced lanthanide fluoroimmunoassay using a monoclonal antibody against an ivermectin-transferrin conjugate. The monoclonal antibody, raised in Balb C mice, showed cross-reactivity with eprinomectin (92%), abamectin (82%) and doramectin (16%). The limit of detection of the assay (mean + 3 SD), calculated from the analysis of 17 known negative samples, was calculated as 4.6 ng/mL. Intra- and inter-assay RSDs were determined as 11.6% and 15.8%, respectively, using a negative bovine milk sample fortified with 25 ng/mL ivermectin. Six Friesian milking cows were treated with ivermectin, three with a pour-on formulation of the drug and three with an injectable solution at the manufacturer's recommended dose rate. An initial mean peak in ivermectin residue concentration was detected at day 4 (mean level = 47.5 ng/mL) and day 5 post-treatment (mean level = 26.4 ng/mL) with the injectable form and pour-on treatment, respectively. A second peak in residue concentration was observed using the DELFIA procedure 28 days post-treatment in both treatment groups (23.1 ng/mL injectable and 51.9 ng/mL pour-on). These second peaks were not confirmed by HPLC and must at this time be considered to be false-positive results. By day 35 after treatment the mean ivermectin residue concentration of both groups fell below the limit of detection of the assay.

Animals↗