Efficacy of ivermectin against Strongyloides stercoralis in humans.

Okinawa Prefecture is an endemic area of Strongyloides stercoralis infection. Since treatment of this infection remains unsatisfactory, we evaluated the efficacy of ivermectin. Twenty-three patients were treated with a single oral dose of ivermectin (mean +/- SD, 105.5 +/- 20.8 mcg/kg of body weight), followed by a second dose two weeks later. The rate of cure was 85.7% at 2 weeks after the first treatment, and 90.5% at 2 weeks after the second treatment. Side effects occurred in 2 patients (8.7%), but they were mild and transient. The results indicate that ivermectin might be useful and relatively safe for the therapy of Strongyloides stercoralis infection as an alternative to thiabendazole or mebendazole.

[Clinical study on ivermectin against 125 strongyloidiasis patients].

We treated 125 patients with strongyloidiasis (78 males and 47 females) by 2 oral doses of ivermectin (6 mg) at 2-week interval, and obtained the following results: 1. Eradication rate after treatment was 86.4% (108 of 125 patients), responsively. Out of the total 17 patients were resistant (non-responsive) to treatment, 8 patients received a further course of ivermectin and all Strongyloides stercoralis in their feces were eradicated. 2. Side effects were observed in 7.2% of the patients after the first dose treatment and in 3.2% after the second dose. But all symptoms were mild and self-limited. Although liver disfunction developed in 13.6% of the patients, no symptoms occurred and no special treatment was required. 3. Positive rate of anti-HTLV-I antibody in the resistant group was significantly higher (80.0%) than in the eradicated group (29.2%) and in the stool-negative group (0%). 4. Although eosinophils before treatment in the eradicated group was significantly higher than that of controls, there was no significant difference between the resistant group and controls. IgE levels in the resistant group was significantly lower than in the eradicated group. We would like to conclude that IVM is the best drug for treatment of the patient with Strongyloides stercoralis not only from this results but also our previous reports which had investigated the clinical efficacy on thiabendazole, mebendazole and albendazole.

[Clinical study on symptoms in patients with strongyloidiasis].

We treated strongyloidiasis patients and obtained the following results: Of the 299 patients (184 males and 115 females), 81 patients (27.1%) had no complaints before treatment, 218 patients complaints of some symptoms, including arthralgia and/or lumbago (28.4%), abdominal pain and/or borborygmus (19.3%), numbness of extremities (18.1%), constipation (16.3%) and itching (15.7). We treated 219 patients with mebendazole and symptoms improved after treatment described below: Thirty-seven of the 63 patients (58.7%) with arthralgia and/or lumbago improved. Twenty-seven of the 36 patients (75.0%) with numbness of extremities improved. Thirty-one of the 32 patients (96.9%) with heartburn improved. We treated 26 patients with mebendazole plus thiabendazole and twelve of 14 patients (85.7%) with abdominal pain and/or borborygmus were improved after treatment. We treated 54 patients with ivermectin and five of 18 patients (27.8%) with arthralgia and/or lumbago were improved after treatment.

[Clinical study on ivermectin against Strongyloides stercoralis].

We previously reported the efficacy of ivermectin (IVM) for the treatment of 23 strongyloidiasis patients. We now reported the efficacy and safety of IVM therapy on 54 patients. Fifty-four patients, 28 males and 26 females, received a single oral dose of IVM one hour before breakfast and this treatment was repeated 2 weeks later. The following results were obtained: 1) The cure rate at 2 weeks after the initial treatment was 92.5% (49 of 53 patients) and 2 weeks after the second course was 96.0% (48 of 50 patients). 2) Four patients (7.4%) complained of diarrhea (n = 2 patients), constipation (n = 1), borborygmus (n = 1), dizziness (n = 1), diplopia (n = 1) and peri-anal itching (n = 1) after the first treatment. Three patients (5.6%) complained of borborygmus (n = 1), itching (n = 1) and exanthema (n = 1) after the second treatment. But all symptoms were mild and required no treatment and subsided in a few days. 3) Positive rate of HTLV-1 antibody was 25.9% in the patients. As described above, although side effects occurred in some cases, they were mild and transient. From these results, we concluded that IVM is an effective drug for strongyloidiasis.

[Clinical study of eradicated and resistant patients to treatment with ivermectin for strongyloidiasis].

We treated 70 patients with strongyloidiasis (41 males and 29 females) with ivermectin (IVM), and obtained the following results: 1. The eradication rates at 1-2 months, 3-4 months and 5-6 months after treatment were 90.7% (49 of 54 patients), 100.0% (47 of 47 patients) and 95.7% (45 of 47 patients), responsively. Twelve patients were resistant (non-responsive) to treatment. 2. When compared to patients whose parasites were completely eradicated, the resistant patients showed the following results: 1) Incidence of symptoms observed before treatment was significantly lower (50.0% vs. 84.5%). 2) Positive rate of anti-HTLV-I antibody was significantly higher (66.7% vs. 20.7%). 3) Blood eosinophil counts before treatment were significantly lower (266.6 +/- 117.2/mm3 vs. 533.2 +/- 429.7/mm3). 4) Serum IgE levels before treatment were significantly lower (217.2 +/- 442.9 IU/ml vs. 1,076.8 +/- 2,108.0 IU/ml). 5) There were no significant differences in age, sex and dosage of ivermectin. 3. Comparing anti-HTLV-I antibody positive and negative patients, the following results were obtained: 1) Eradicated patients; a) Eosinophils and IgE levels before and after the first administration of medicine in anti-HTLV-I antibody positive patients were significantly lower than those of negative patients. b) Gammaglobulin levels before treatment and after both administrations of the drug, IgG before therapy and OKT4/OKT8 after therapy were significantly higher than in anti-HTLV-I antibody positive patients. 2) Resistant patients; Eosinophils after treatment were significantly lower in anti-HTLV-I antibody negative patients than in positive patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical study of albendazole therapy for strongyloidiasis].

We reported the efficacy of albendazole (ABZ) for the treatment of 27 patients with strongyloidiasis. Twenty-seven patients, 23 males and 4 females, received 200 mg of ABZ one hour before breakfast and supper for 3 days and this treatment was repeated 2 weeks later. The following results were obtained: 1) The eradication rate at 2 weeks after the initial treatment was 70.4% (19 of 27 patients) and 2 weeks after the second course was 66.7% (16 of 24 patients). 2) One patients (3.7%) complained of abdominal pain after the first treatment. Four patients (14.8%) complained of headache (n = 2), nausea (n = 1) and exanthema (n = 1) after the second treatment. But all symptoms were mild and required no treatment and subsided in a few days. 3) Positive rate of HTLV-1 antibody was 45.8% in the patients. As described above, side effects occurred in some cases, although they were mild and transient. From these results, it can be concluded that on increased dose of ABZ could be much more favorable for the treatment of strongyloidiasis.