638 Postgrad Med J: first published as 10.1136/pgmj.36.420.638 on 1 October 1960. Downloaded from THE TREATMENT OF AMOEBIC DYSENTERY S. BELL, M.D., M.R.C.P.(EDIN.), D.T.M. & H. Department of Clinical Tropical Medicine, Hospitalfor Tropical Diseases, London, N.W.i Diagnosis of infection with Entamoeba histolytica Recent Advances in Drug Therapy remains the most important practical problem, The groups of drugs available for the treatment and is the essential pre-requisite for effective of intestinal amoebiasis are: treatment. Without reliable parasitological diag- (I) Emetine and its compounds especially nosis follow-up examinations are virtually useless, emetine bismuth iodide. and attempts to assess the curative value of courses (2) Iodoquinoline compounds such as di- of treatment are worthless. In many tropical and hydroxy-iodoquinoline (Yatren, Chiniofon, sub-tropical areas carriers of the cystic form of the Enterovioform, etc.). parasite are so numerous that, until very recently, (3) Organic arsenicals such as Carbasone. radical treatment of them was outside the bounds (4) Antibiotics. ofpossibility. Thus the main effort there has been (5) Synthetic compounds and others, e.g.Protected by copyright. directed to treatment of the patient suffering from Camoform, Glaucarubin, compounds of amoebic dysentery or one of its complications. dichloroacet - 4- hydroxy - n - methylanilide (Entamide). Status of the Parasite Fundamental research both on the amoebic Acute Amoebic Dysentery parasite and on the host parasite relation is of The drug of choice to relieve acute symptoms is great importance, for knowledge is incomplete emetine hydrochloride i gr. daily (6o mg.) by about the pathogenicity of various strains of the subcutaneous injection for four to seven days. organism, and about the factors which may This drug alone, however, even in a longer course, precipitate acute amoebic dysentery and hepatic does not result in a high radical cure rate. By abscess or which cause the parasite to remain in the using it to control the acute symptoms and then cystic stage as a latent infection. changing to oral administration of emetine bis- Hoare2 has attempted to clarify the nomenclature muth iodide (EBI) a much better cure rate can of the large and small race parasites. The small be achieved. EBI should be dispensed in freshhttp://pmj.bmj.com/ race, formerly named Entamoeba histolytica minuta, gelatin capsules and the adult patient is given a is now named Entamoeba hartmanni. It produces course of 3 gr. (i8o mg.) each night for ten nights. cysts of mean diameter Io0± or less. This The drug causes gastric irritation with nausea and parasite is not believed to be pathogenic. Ridley vomiting, and colonic irritation with diarrhoea. and Schofield5 reported a study of the symptoms To diminish the former the patient is given a meal related to infection with it and showed no correla- at 6 p.m. and then no more food or drink until tion with symptoms of dysentery. The large race next morning. At 9 p.m. he is given a rapidly- on September 29, 2021 by guest. parasite Entamoeba histolytica produces cysts of acting sedative of which soluble phenobarbitone mean diameter about 2OtL. It may be a non- gr. i (6o mg.) by subcutaneous injection is pathogenic commensal, as is probably the case with suitable; and at io p.m. he is given the capsule those harbouring it in non-tropical environments. containing EBI. It is common for the patient to On the other hand some strains are virulent patho- awaken at about 2 a.m. feeling nauseated and he gens, ingesting red cells, invading the tissues, and may retch or vomit a little gastric juice containing causing amoebic dysentery and its complications. a few granules of the drug. If much of the dose is As yet, only detailed investigation by an experi- returned an additional dose is given at the end of enced worker, using three-week-old weanling rats the normal course. This gastric irritation often as experimental animals, will reveal differences in diminishes after the first few nights. It is pathogenicity of various strains of the large race probable that confining the patient to bed with parasites.4 only the use of the bathroom and toilet helps to 639 October I960 BELL: The Treatment of Amoebic Dysentery Postgrad Med J: first published as 10.1136/pgmj.36.420.638 on 1 October 1960. Downloaded from lessen the trouble. The diarrhoea due to EBI sold under the name Furamide, Boots Pure Drug commonly begins after about five or six days on Co. Ltd.). Details are reported by Woodruff and treatment. It is most important to recognize that Bell7 and a field trial in a tropical area is reported this is a side-effect of the drug, and not to regard by Marsden.3 This drug has given very good it as an indication for prolonged treatment. Some results in the radical cure of cyst passers and apart alleviation can be obtained by the use of a simple from some flatulence there have been no side- kaolin mixture and the patient should be assured effects. It is possible that this drug may prove that the diarrhoea will abate when the drug is suitable as a replacement for EBI for use in acute stopped. dysentery after symptoms have been controlled In the course of trials of many new drugs none by the use of emetine hydrochloride, for use ir~ has been found as yet which results in a higher cure treating cyst passers as out-patients, and for use in rate than EBI when properly administered.6 repeated courses for food-handlers in catering establishments in tropical and sub-tropical areas. Carriers of Amoebic Infection The drug is supplied in tablets each of 0.5 g. and Whether or not to treat those excreting cysts who the dose has been calculated on the basis of 20 mg. have no dysenteric symptoms depends on the per kg. body weight per day for ten days. history of the patient's condition. If he has suffered from bowel trouble and particularly if Treatment of Hepatic Complications of he has come from a tropical or subtropical area, Amoebic Infection and if the mean diameter of the cysts is greater Apart from aspiration of an abscess in the liver, than io li, it is wise to give treatment. EBI which is more successful and safer than open without preliminary emetine injections is most operation and drainage (except in the uncommon likely to cure the patient. case of an abscess in the left lobe), the treatment Trials with many other drugs have been made of hepatic amoebiasis is with emetine hydro- in the hope of finding one as effective but without chloride by subcutaneous injection in a dose of Protected by copyright. the. side-effects of EBI. i gr. (6o mg.) daily for ten days; or with chloro- Among the antibiotics tried are fumagillin and quine diphosphate or sulphate by mouth in a dose paromycin (Humatin, Parke Davis & Co.). The of 300 mg. of base thrice daily for two days and record of a trial of fumagillin was included in the then I50 mg. of base thrice daily for at least I2 report by Woodruff et al.6 Of 31 patients days. Where the parasites are present in the excreting cysts 27 had follow-up examinations bowel contents treatment with one of the drugs after treatment and one relapsed. Of three already mentioned is also required. Chloroquine who had trophozoites in their bowel contents, has no appreciable effect on these. two did not respond to the drug. Indigestion and desquamation of skin especially on the hands A trial with Humatin was REFERENCES were toxic effects. I. BELL, S., and WOODRUFF, A. W. (I960), Amer. J. trop. Med. reported by Bell and Woodruff.' Twenty patients 9 155. who were excreting cysts were treated and I9 were 2. HOARE, C. A. (I958), Rice Institute Pamphlet, 45, 27. 3. MARSDEN, P. D. (I960), Trans. roy. Soc. trop. Med. Hyg. http://pmj.bmj.com/ followed-up for periods ranging from one month 54, 396. to over one year with one relapse. Diarrhoea 4. NEAL, R. A. (1951), Ibid,. 44, 439. was a side-effect of this drug. S. RIDLEY, D. S., and SCHOFIELD, F. D. (I957), Ibid., si, 5I8. 6. WOODRUFF, A. W., BELL, S., and SCHOFIELD, F. D. The most promising of the newer synthetic (I956), Ibid., 50, I14. compounds has been Entamide furoate (now being 7. WOODRUFF, A.- WV., and BELL, S. (I960), Ibid., 54,389. on September 29, 2021 by guest..