Amebicidal

Carbarsone (Amebarsone) was once widely used for the treatment of intestinal amebiasis. Like other arsonic acids, however, carbarsone may cause skin rashes and even damage to the vision. Although it is stiU available for medicinal use, it is really obsolete as an amebicide because less toxic and more effective nonarsenicals are now available (174). 

Pyrazole, 3-(trifluoromethyl)-4,5-trimethylene as amebicide, 5, 291 Pyrazole, 3-triflyl-4-phenyl-synthesis, 5, 282 Pyrazole, 1,3,4-triiodo-synthesis, 5, 234 Pyrazole, 1,3,5-trimethyl-isomerization, 5, 221 Pyrazole, 3,4,5-trimethyl-bromination, 5, 240 halogenation, 5, 89 reactions... 

List some nursing diagnoses particular to a patient taking an anthelmintic, antimalarial, or amebicide drug. 

Discuss ways to promote an optimal response to therapy, how to manage adverse reactions, and important points to keep in mind when educating patients about the use of the anthelmintics, antimalarials, and amebicides. 

Chloroquine (Aralen) is also used in die treatment of extraintestinal amebiasis (see section on Amebicides). Doxycycline is also used to treat infections caused by Neisseria gonorrhoeae, Treponema pallidum, Listeria monocytogenes, Clostridium, and Bacillus anthracis when penicillin is contraindicated. Quinine also may be used for die prevention and treatment of nocturnal leg cramps. 

Amebicides (drugs that kill amebas) are used to treat amebiasis caused by the parasite E. histolytica. An ameba is a one-celled organism found in soil and water. Examples of amebicides are listed in the Summary Drug Table Amebicides. 

These dragp are amebicidal (ie, they kill amebas). There are two types of amebiasis intestinal and extradntestinal. 

Iodoquinol (Yodoxin) and metronidazole (Flagyl) are used to treat intestinal amebiasis. Metronidazole is also used to treat infections caused by susceptible microorganisms and is discussed in Chapter 11. Fkromomycin is an aminoglycoside with amebicidal activity and is used to treat intestinal amebiasis. Chloroquine hydrochloride (Aralen) is used to treat extraintestinal amebiasis. 

Before the first dose of an amebicide is given, the nurse records the patient s vital signs and weight. The nurse evaluates the general physical status of the patient and looks for evidence of dehydration, especially if severe vomiting and diarrhea have occurred. 

Monitoring and Managing Adverse Reactions The nurse monitors die patient for adverse reactions associated witii die amebicides such as diarrhea and gastrointestinal upsets. Otiier adverse reactions are listed on die Summary Drug Table Amebicides. 

Educating the Patient and Family The nurse stresses the importance of completing the full course of treatment. The nurse should provide the following information to patients receiving an amebicide on an outpatient basis ... 

Besides constipation-related IBS, several studies have also suggested abnormalities of colonic bacterial composition in chronic idiopathic constipation [125]. Here again antibiotic treatment with vancomycin [126, 127], rova-mycin (in combination with diphetarsone, an amebicidal agent) [128,129] or erythromycin [130], which, however, displays a prokinetic activity [131, 132], proved to be capable of reversing long-lasting constipation. Furthermore, the efficacy in both clinical conditions of probiotics [133-135] lends further support to the pathogenic role of bowel flora. 

McCowen MC, Callender ME, Lawlis JF Jr. (1951) Fumagillin (H-3), a new antibiotic with amebicidal properties. Science 113 202-203. 

Thus the main quality of chloroquine that exceeds all other antimalarial drug is its effect on erythrocytic schizonts (hematoschizotropic action). However, chloroquine also possesses amebicidal action. It has also been observed to have immunodepressive and antiarrhythmic properties. 

This drug has a direct amebicidal effect against trophozoites E. histolytica in tissues, and it is not active against cysts in either the lumen or intestinal walls, or in other organs. The mechanism of action of emetine consists of the blockage of protein synthesis in eukaryotic (but not in prokaryotic) cells. It inhibits the process of polypeptide chain formation. Protein synthesis is inhibited in parasite and mammalian cells, but not in bacteria. 

Niridazole exhibits schistosomicide and amebicidal action. The mechanism of action is not known. It seems likely that it is concentrated in the parasite organism, which causes inhibition of phosphorylase activation, which is expressed in the depletion of glycogen reserves. 

Acute intestinal amebiasis Due to Entamoeba histolytica as adjunct to amebicides. 

Metronidazole also is available for topical and intravaginal use and also is used orally as an amebicide. 

Metronidazole is the most effective agent available for the treatment of individuals with all forms of amebiasis, with perhaps the exception of the person who is asymptomatic but continues to excrete cysts. That situation calls for an effective intraluminal amebicide, such as dUoxanide furoate, paromomycin sulfate, or diiodohy-droxyquin. Metronidazole is active against intestinal and extraintestinal cysts and trophozoites. 

The aminoglycoside paromomycin Humatin) has a mode of action identical to that of the other aminocycli-tols and is directly amebicidal. It is not absorbed from the intestinal tract and thus has its primary effect on bacteria, some amebas (e.g., E. histolytica), and some helminths found in the lumen of the intestinal tract. Side effects are limited to diarrhea and gastrointestinal upset. 

Mechanism of Action A nitroimidazole derivative that disrupts bacterial and protozoal DNA, inhibitingnucleicacidsynthesis.Therapeutic E/fcct Produces bactericidal, ID-antibacterial, amebicidal, and trichomonacidal effects. Produces anti-inflammatory and immunosuppressive effects when applied topically. 

Metronidazole plus a luminal amebicide is the treatment of choice for amebic colitis and dysentery. Tetracyclines and erythromycin are alternative drugs for moderate colitis but are not effective against extraintestinal disease. Dehydroemetine or emetine can also be used, but are best avoided because of toxicity. 

The treatment of choice for extraintestinal infections is metronidazole plus a luminal amebicide. A 10-day course of metronidazole cures over 95% of uncomplicated liver abscesses. For unusual cases in which initial therapy with metronidazole has failed, aspiration of the abscess and the addition of chloroquine to a repeat course of metronidazole should be considered. Dehydroemetine and emetine are toxic alternative drugs. 

Metronidazole or tinidazole is the drug of choice in the treatment of all tissue infections with E histolytica. Neither drug is reliably effective against luminal parasites and so must be used with a luminal amebicide to ensure eradication of the infection. 

Iodoquinol (diiodohydroxyquin) is a halogenated hydroxy-quinoline. It is an effective luminal amebicide that is commonly used with metronidazole to treat amebic infections. Its pharmacokinetic properties are poorly understood. Ninety percent of the drug is retained in the intestine and excreted in the feces. The remainder enters the circulation, has a half-life of 11-14 hours, and is excreted in the urine as glucuronides. 

Diloxanide furoate is a dichloroacetamide derivative. It is an effective luminal amebicide but is not active against tissue trophozoites. In the gut, diloxanide furoate is split into diloxanide and furoic acid about 90% of the diloxanide is rapidly absorbed and then conjugated to form the glucuronide, which is promptly excreted in the urine. The unabsorbed diloxanide is the active antiamebic substance. The mechanism of action of diloxanide furoate is unknown. 

Diloxanide furoate is considered by many the drug of choice for asymptomatic luminal infections. It is not available commercially in the USA, but can be obtained from some compounding pharmacies. It is used with a tissue amebicide, usually metronidazole, to treat serious intestinal and extraintestinal infections. Diloxanide furoate does not produce serious adverse effects. Flatulence is common, but nausea and abdominal cramps are infrequent and rashes are rare. The drug is not recommended in pregnancy. 

N.A. Isoquiniline, berberine, coptisine, worenine.99 Antibacterial, amebicidal and antidiarrheal. 

Cyclization of 3-aminoquinazoline-4-thiones (375) with carbon disulfide gave the zwitterionic l,3,4-thiadiazolo[3,2-c]quinazoline (376) (771JC(B)1110]. Synthesis from properly functionalized 1,3,4-thiadiazole precursors was also reported [83JCS(P1)2011], according to which the 2-(2-nitrophenyl)-l,3,4-thiadiazoles (377) were reduced and cyclized to 378. 1,3,4-Thiadiazoloquinazolines were shown to exhibit amebicidal... 

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