1.Efficacy of the use of adsorbents in the treatment of paraquat poisoning of dog
Masakazu Kawai ; Masahide Koyama ; Yoshihiro Kaneko ; Sadanori Ogasawara
Journal of the Japanese Association of Rural Medicine 1981;30(4):791-802
While there are not any effective antidotes for paraquat poisoning up to this time, several procedures such as gastric lavage, dosing of emetics and adsorbents, hemodialysis, peritoneal dialysis and hemoperfusion have been applied in treatment of paraquat intoxication.
In this study, we determined efficacy of the combined application of oral administration of an adsorbent (Adsorbin) and hemoperfusion using activated charcoal (HEMOSORBA: activated charcoal coated collodion, The ASAHI Medical Co.) in dogs being given orally paraquat in the amount of 40 mg per kg of the body weight.
Efficacy of the treatments was in order of the combined application of dosing Adsorbin and the hemoperfusion with Hemosorba, single use of dosing Adsorbin and single application of the hemoperfusion.
Oral administration of the adsorbent was carried out only once, either one hour or three hours after forced dosing of paraquat, and the hemoperfusion was started either one or three hours after paraquat dosing and continued for six hours in each case.
Effectiveness of the treatment on the survival-time was superior in the case of dosing the adsorbent and starting the hemoperfusion one hour after paraquat administration.
As a sign of developing lung fibrosis was found on histopathological observation in dogs survived for twenty days after starting the experiment, even in case of the combined treatment with the best results, observation of longer period seems to be necessary for obtaining more information after treatment. And it is furthermore advisable that the treatment, especially the hemoperfusion, should be continued or carried out more than one time until the concentration of paraquat in blood plasma decreases to the safe level.
2.The Effects of Administration of an Emetic on Paraquat Toxicity
Masakazu Kawai ; Masahide Koyama ; Yoshihiro Kaneko ; Sadanori Ogasawara
Journal of the Japanese Association of Rural Medicine 1983;32(4):887-892
There have been hardly any cases of paraquat poisoning during normal use of paraquat as a herbicide, but there have been a number of deaths or cases of serious poisoning due to ingestion of paraquat products as the result of suicidal intent or accidents, and the survival rate is extremely low. To prevent the occurrence of paraquat poisoning, some experiments have been conducted in which emetics were added to paraquat products.
In this study, we determined the efficacy of including Triazolopyrimidine compound (pp) as an emetic in a paraquat product, when it was orally administered to dogs under the starved (condition A) or unstarved (condition B) conditions. When paraquat was orally given to the dogs (40 mg/kg body weight) under condition A, emesis occured four to six hours after the dosing. However, in the case of giving a dose of the mixed solution of paraquat and pp (PQ 40mg/kg, pp 2mg/kg), vomiting took place after four to six minutes (vomited rate of PQ: 86.4%) and seven to twenty minutes (vomited rate of PQ: 61.2%) under conditions A and B respectively. The average survival period in the case of the paraquat dosing was fifteen days and six days under conditions A and B respectively. However, in the case of giving a dose of the mixed solution of paraquat and pp, it was more than 20 days and 12.7 days under conditions A and B respectively.
The results of the experiment suggest that the inclusion of emetics is one of the effective means of preventing paraquat poisoning. As the amount of ingested paraquat is usually large in the case of suicidal intention, it is conceivable that an amount greater than the lethal dose will remain in the gastrointestinal system even if the emetic included in the paraquat produces vomiting in patients. Since the inclusion of emetics in paraquat products leads to an early occurrence of vomiting in the victim, the chances of finding him or her earlier should be increased. This would, in turn, make earlier treatment possible.