Praziquantel, Oxamniquine, and Metrifonate in the Treatment of Schistosomiasis in Riyadh

Abstract

This study sought to compare the effectiveness and side effects of praziquantel versus oxamniquine in treating 200 patients with Schistosoma mansoni infection and praziquantel versus metrifonate in treating 100 patients with S. haematobium infection. Praziquantel and oxamniquine were given in single doses of 40 mg/kg body weight and 25 mg/kg, respectively. Metrifonate was given in doses of 10 mg/kg, and repeated three times at fortnight intervals. In S. mansoni infections, the cure rate was 96% for praziquantel and 91% for oxamniquine. In S. haematobium infections, the cure rate was 98% for praziquantel and 90% for metrifonate. Side effects were generally minor and temporary and were noted in 44% of patients treated with praziquantel, in 60% of patients treated with metrifonate, and in 70% of the patients treated with oxamniquine. The most common side effects were dizziness and abdominal pain. It is concluded that the three drugs are effective against the species of Schistosoma present in our area. Praziquantel appears to be the drug of choice for S. haematobium. Praziquantel and low-dose oxamniquine (25 mg/kg) were comparable in their effect on S. mansoni.

Drugs for treating urinary schistosomiasis

“…The trials detected no difference in parasitological treatment failure at different time points and with different metrifonate regimens. However, in one trial both drugs performed poorly (de Jonge 1990 SDN), and in one trial both performed well (Al Aska 1990 SAU) (see Analysis 10.3). The trial where both drugs performed poorly for parasitological failure has been discussed above and this is likely to be due to the very sensitive method for detecting eggs.…”

“…Only Al Aska 1990 SAU reported adverse events; dizziness was more common after praziquantel (RR 2.9, 95% CI 1.59 to 5.3; 100 participants, one trial, Analysis 10.4). Dizziness (20% in the praziquantel group and 10% in the metrifonate group) and abdominal pain (12% both in the praziquantel and metrifonate group) were the most common side effects (Appendix 5).…”

Therapeutic and Operational Profiles of Metrifonate and Praziquantel in Schistosoma haematobium Infection

“…These adverse reactions are of transient nature only and always disappear spontaneously. In fact, since a similar pattern of adverse reactions is observed after treatment with oxamniquine it may be assumed that the side effects are actually related to immunological events related to the shift, subsequent sequestration and eventual disintegrating adult worms [29]. Adverse reactions are summarized in Table 2.…”

“…A retrospective study involving 25,693 patients treated with 60 mg/kg for S. japonicum infection, including 1,175 with advanced disease, 500 acute cases and 10 patients with cerebral involvement, revealed serious side-effects in only 0.5 % [18]. Studies investigating adverse reactions after treatment with metrifonate or praziquantel in randomized groups of patients did not reveal any significant difference in the occurrence of side effects [27,29]. There is, however, a considerable advantage of praziquantel in comparison to metrifonate, i.e.…”

“…Inversely, praziquantel may be overdosed by a factor of 20 without causing acute toxicity in animals [2]. Adverse reactions after administration of praziquantel and metrifonate are very similar and mainly present as dizziness, abdominal discomfort, arthralgia, nausea, vomiting, diarrhoea, rash, itching and fatigue [2,15,22,29]. These adverse reactions are of transient nature only and always disappear spontaneously.…”