The pr;u-liti(iiu'r 's iibligatiiiii t(i tlic |i;itieTit has not been 

 fiiltilli'd until a suitablo cliofk is made on the results of the 

 tioatiui'iif. In the case of most parasites, it is advisable to 

 wait two weelis before a reexamination since some anthelmin- 

 tics definitely inhibit egg production in some parasites. With 

 such a specialized [larasite as Enlfrobiiis vcrniicularis a longer 

 period of time is needed to determine freedom from infection 

 following treatment. In evaluating the efficacy of any treat- 

 ment due cognizance slionld be taken of the possibilities of mi 

 grating larvae developing to maturity and also of possible 

 exposure to reinfection following treatment. 



Choice of tub Anthelminxic. An ideal anthelmintic would 

 be one which could be given with complete safety to the pa- 

 tient; would be nontoxic in all cases; would be effective in re 

 moving all of the i^articnlar kind or kinds of worms against 

 which it was directed; could be easily administered even in 

 large scale treatments; and would be sufficiently cheap that 

 cost would be no obstacle to its use. 



In spite of the exuberant enthusiasm of some investigators, 

 the ideal anthelmintic has yet to be discovered. Drugs which 

 on first test seem to fulfill such specifications are usually found 

 wanting in some rcsjject when submitted to adequate field trials 

 on large numbers of individuals. 



Keeping in mind the general specificity of anthelmintics, it is 

 best to select the most effective drug available provided no 

 general or specific contraindications exist for the use of that 

 specific drug. If contraindications are present, they usually 

 modify either the selection of the anthelmintic or the dose em- 

 ployed. The presence of more than one nematode parasite or 

 concomitant infections with cestode or trematode parasites fre- 

 quently changes the picture. In the latter case the administra- 

 tion of a single drug will seldom be effective in eradicating such 

 diverse helminths. Even in multiple nematode infections treat- 

 ment with a single anthelmintic may not be effective. In the 

 case of certain parasites, a combination of two drugs may be 

 of value such as the chenopodium-tetrachlorethylene mixture in 

 concomitant ascarid and hookworm infectious in man. In other 

 cases, different kinds of parasites have to be attacked by means 

 of separate treatments. 



One method of attack has been suggested as being of value 

 for the removal of all intestinal helminths in certain animals. 

 DeRivas (1926, 1S>27. 1936) advocated the use of trans-duodenal 

 lavage with hot water or hot saline for parasites in the small 

 intestine and colonic lavage with l:.'iOOO copper sulphate solu- 

 tion for parasites in the large bowel. He carried out experi- 

 ments on dogs and man and reported that the use of two liters 

 of hot saline at temperatures of 4.5° to 47° C. resulted in the 

 elimination of worms with little discomfort to the patient. Hall 

 and Shillinger (1926) used the method on dogs with water 

 having an initial temperature of 49° to .52° C. in the container 

 and cooled to 47° to 48° C. at the time of administration. The 

 use of 2 to 4 gallons of fluid resulted in an efficacy of 97.7 

 percent against ascarids, 77 percent against hookworms and 

 51.6 percent against tapeworms. However, the treatment re- 

 sulted in the death of half the experimental dogs and was re- 

 sponsible for hemorrhage, enteritis and intestinal edema in 

 those surviving. The safety of this method of treatment does 

 not seem to be well established and perhaps for this reason 

 the technique has never become popular. 



Somewhat the same method of treatment was used by Whit- 

 ne3- (1939) for removing various species of intestinal parasites 

 from dogs. He employed a 1.5 percent solution of hydrogen 

 peroxide in warm water and injected this solution per rectum 

 under pressure until the act of vomiting indicated that the 

 material had passed through the entire gastro intestinal tract. 

 The treatment was said to be highly effective against all of 

 the helminth parasites commonly found in the gastrointestinal 

 tract of the dog. Reactions were encountered in some of Whit- 

 ney's cases. Serious after effects in the form of gastro enteritis 

 and paralysis have since been reported by some veterinarians 

 following the use of the treatment. Apparently, the treatment 

 does not have an adequate margin of safety. 



PURQ.^TION. The administration of a purgative in connection 

 with anthelmintic medication is of the utmost importance in 

 the case of most drugs. Usually the purgative acts to promote 

 the efficiency of the anthelmintic by distributing it throughout 

 the intestinal tract and by aiding in the prompt expulsion of 

 the parasites. In most cases, purgation is of marked value in 

 safeguarding the patient by reducing the absorption of the 

 anthelmintic. Some purgatives also give local protection against 

 the irritating action of certain drugs. 



The choice of the purgative is conditioned by the method 

 of treatment and the drug or drugs employed. The use of the 

 chlorinated hydrocarbon group of anthelmintics requires the 

 administration of saline purgatives, since fats and oils tend to 

 increase the ab.sorption of such compounds, a thing which re- 

 sults in more marked reactions to the treatment. In the ease 



of oil of chenopodium, castor oil is the purgative of choice 

 even though saline jiurgatives have been used with this drug. 

 Castor oil not only i)romotes promjit expulsion of the drug 

 and reduces absorption but it also exerts a local emollient ac- 

 tion and protects the intestinal mucosa against the irritating 

 properties of chenopodium. 



Purgatives are usually administered concomitantly with the 

 anthelmintics but practice in this regard varies with the host, 

 the parasite and the drug employed. In treating large numbers 

 of hookworm patients at one time, it is customary to give 

 carbon tetrachloride or tetrachlorethylene in a solution of 

 magnesium or sodium sulphate. However, in this case the drug 

 may be given in gelatin capsules and immediately preceded or 

 followed by the purgative. In the treatment of Ascaris infec- 

 tions in man w'ith hexylresorcinol, it is the usu.al practice to ad- 

 minister the purgative 24 hours after the drug. Calomel has 

 always been the time honored purgative for use with santonin 

 but it is probable that better results would follow the employ- 

 ment of a saline purgative. 



Adequate protection presupposes the administration of full 

 doses of the purgative. Perhaps more injury has followed the 

 use of inadequate doses of purgatives in connection with anthel 

 mintics than has come from over dosing with the anthelmintics 

 themselves. By this we mean that over doses of anthelmintics 

 will frequently be tolerated if accompanied by adequate doses 

 of purgatives whereas many fatalities have resulted from stand 

 ard doses of certain anthelmintics used without adequate pur- 

 gation. Therefore, in using nearly all anthelmentics, attention 

 should be given to gauging accurately both the dose of the 

 anthelmintic and the dose of the purgative. 



In event that adequate purgation does not ensue within a 

 reasonable time, prompt measures must be taken to protect the 

 patient. High enemas should be resorted to and, if necessary, 

 an additional dose of the purgative should be given by duo 

 denal tube. Warm applications to the lower extremities and 

 to the abdomen will hasten evacuation. The point of most im- 

 portance in such circumstances is the rapid institution of cor- 

 rective measures. Every effort should be made to stimulate 

 bowel movements and promote prompt expulsion of the anthel- 

 mintic. If the patient is permitted to go unaided, increased 

 absorption of the anthelmintic will ensue and the life of the 

 individual may be endangered. 



No doubt much of the distress following the administration 

 of many anthelmintics is caused by the purgative and not by 

 the anthelmintic. Malloy (1926) showed that the nausea, dizzi- 

 ness, headache and abdominal pain following the administration 

 of carbon tetrachloride in magnesium sulphate solution was 

 due in most cases to the purgative and not to the anthelmin- 

 tic. Wright, Bozicevich and Gordon (1937) found that reac- 

 tions to the tetrachlorethylene treatment in children were 

 markedly reduced when magnesium citrate solution, a more 

 pleasant and palatable purgative, was used instead of mag- 

 nesium sulphate. In most cases, the symptoms described above 

 are not alarming and usually pass off rapidly after the bowels 

 move. 



Anthelmintic Medication for Nematode Parasites 

 of Man 



TREATMENT TOR ASCARIS LUMBRICOIDES INFTtCTION 



HEXYLRESORriNOL. This is the drug of choice since it is 

 highly effective and is safer than other drugs formerly em- 

 ployed for this purpose. 



Proper fasting is important since hexylresorcinol combines 

 with protein and is rendered inert insofar as its anthelmintic 

 action is concerned. The patient should be given a light sup- 

 per on the evening before treatment and the drug should be 

 administered on an empty stomach the following morning. 

 Hexylresorcinol is used in the form of Caprokol pills, each of 

 which contains 0.2 gram of the drug. The dosage for adults 

 consists of 5 pills or a total of 1.0 gram. The dosage for 

 children is, as follows: Under six years, 2 pills; six to eight 

 years, 3 pills; eight to twelve years, 4 pills; over twelve years, 

 .5 pills. 



The pills should be swallowed with a little water; special 

 care should be taken that they are not chewed since the drug 

 is a local irritant and produces annoying burns. Children in 

 particular should be observed closely to make sure that the 

 pills are properly swallowed. Food should be withheld for 4 

 hours following administration of the drug. A saline purga- 

 tive should be given 24 hours after treatment to sweep out 

 the dead worms. 



As a usual thing there is little or no discomfort from the 

 drug although some patients may complain of nausea and 

 slight abdominal pain. Occasionally a slight burning sensation 

 in the epigastrium is noted but this soon passes off. 



337 



