Activity of quinfamide against natural infections of Entamoeba criceti in hamsters: a new potent agent for intestinal amoebiasis.

Abstract

A novel tetrahydroquinolinyl ester, quinfamide, administered orally in multiple doses for 3 days had an ED50 of 0.25 mg/kg/day (total dose 0.75 mg/kg) for eradicating Entamoeba criceti in hamsters in several tests. It was significantly more active by direct comparison than 3 commercially available amoebicides and at least as active as 2 other esters of the parent compound, 1-(dichloroacety)-1,2,3,4-tetrahydro-6-quinolinol. After administration of a single dose, ED50 calculations for quinfamide averaged 0.9 mg/kg. Quinfamide was considerably more active than the other tetrahydroquinolinols, diloxanide furoate and teclozan, and it was approximately 1.5 times more active than etofamide; a statistical significance between the latter 2 drugs could be demonstrated in one of 4 tests. Administered prophylactically, quinfamide was shown to protect hamsters from re-infection with E. criceti. It also inhibited propagation of E. histolytica in vitro at a concentration of 20 microgram/ml. No adverse effects were noted in rodents after a single dose as high as 10 g/kg. Daily administration to monkeys of doses up to 500 mg/kg for as long as 37 days produced no pharmacological aberrations during or after medication; haematological studies and urine analyses were normal and no gross or microscopical tissue changes attributable to quinfamide were observed. No toxicity was revealed following acute (2 g/kg) and chronic (500 mg/kg/day x 31 days) administration of the drug to dogs and rats, respectively.

• Authors: R G Slighter, A Yarinsky, H P Drobeck, D M Bailey
• Journal: Parasitology (Parasitology) Vol. 81 Issue 1 Pg. 157-68 (Aug 1980) ISSN: 0031-1820 [Print] England
• PMID: 6252530 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Amebicides
• Quinolines
• quinfamide

Topics

• Amebiasis (drug therapy)
• Amebicides (therapeutic use)
• Animals
• Cricetinae
• Dogs
• Drug Evaluation, Preclinical
• Entamoeba histolytica (drug effects)
• Entamoebiasis (drug therapy)
• Female
• Macaca mulatta
• Quinolines (adverse effects, therapeutic use)
• Structure-Activity Relationship