New drugs for irradiation sickness.

Abstract

In continuance of an earlier study of radiation sickness and its management (Ellis and Stoll, 1952), a controlled trial of a series of new drugs has been carried out at the Peter MacCallum Clinic, Melbourne, Australia. Results were recorded on a sheet (Fig. 1) similar to that used in the first investigation. The drug under trial was changed weekly to avoid selection of cases. A lactose tablet was used initially as an inert control, but there was no attempt to make all the drugs up in tablets of similar size, shape, and color. The preparations under trial were pyridoxin hydrochloride; chlorpromazine hydrochloride (Largactil, May and Baker), cyclizine hydrochloride (Marzine, Burroughs Wellcome); Pacatal hydrochloride (William R. Warner). The patient was questioned as to alleviation of symptoms one week after the drug was prescribed. If relief was obtained, the drug was continued for that case until the end of treatment. Otherwise, the drug of the second week was prescribed. A total of 212 drug trials were carried out during a period of eighteen months, ending with April 1956. Pyridoxin hydrochloride was shown in the previous controlled trial to be the most efficacious of the drugs available at that time, and it is of interest that it afforded relief of symptoms in an almost identical percentage of cases in this study. Its use has been widespread for some years, and some authorities have claimed relief in 90 per cent of cases (Shorvon, 1949). In the last five years, however, various new compounds with anti-emetic action have been introduced. Chlorpromazine hydrochloride, now widely used for many purposes, was reported by Marks (1954) as relieving symptoms in 80 out of 84 cases of radiation sickness, i.e., in 95 per cent. For each of these drugs the proportion of relief quoted is very much higher than was obtained in this controlled trial, and a cautious attitude must be adopted when details as to individual symptoms are not supplied. Thus, Loftstrom and Nurnberger (1946), in a report on benadryl, claimed relief of vomiting in 8 out of 10 cases (80 per cent), nausea in 13 out of 19 (68 per cent), anorexia in 8 of 18 (44 per cent), and listlessness in 4 of 13 (31 per cent) cases. These authors reported, with every justification, that some relief of symptoms had been obtained in 18 out of 19 patients, that is, in 95 per cent of their series. Cyclizine hydrochloride is a new anti-histamine compound which has been used recently in the treatment of nausea and vertigo of all types. It has been tried for radiation sickness in the United States, and relief of symptoms has been claimed in 75 to 80 per cent of cases (personal communication). The only side-effect reported is occasional slight drowsiness; no serious toxic symptoms have so far been observed.