We have, as yet, no means of determin ing accurately the dose of antitoxin suit able to each case of diphtheria. It de pends upon the severity of the case, the time of injection, and to a slight extent upon the age of the patient. We judge of the severity of the case by the location and extent of the membrane and the de gree of constitutional depression. The tendency is constantly toward the use of larger doses of the antitoxin. In the early days of its use the antitoxin was comparatively weak and large quantities, as much as 20 cubic centimetres, were required for a single dose. Many of the unfavorable results at first reported were doubtless due to the large quantities of horse-serum which it was necessary to inject. It was also a difficult and painful procedure to introduce such quantities of fluid hypodernaically. The antitoxin now used is many times stronger; so that even the largest doses rarely require more than 5 cubic centimetres. This concen tration of the serum leaves us much more free in increasing the power of the first injection.
For children under two years of age, severe cases, including all laryngeal cases, are usually given 1000 units, mild cases GOO to 700 units for the first dose. For children over two years, in severe cases, including all laryngeal, 1500 to 2000 units are employed, in mild cases 1000 units for the first dose. Some physicians employ stronger doses than these; as much as 3000 units may be given at a single injection. If no marked improve ment follows the first injection, the dose may be repeated in from twelve to twenty-four hours. Third injections may be given, but are rarely necessary and are of little benefit, as the antitoxin has but little influence by that time.
In communities in which diphtheria is prevalent, GO units sufficient to afford protection. Among 10,000 thus treated only 10 acquired diphtheria. To those who developed diphtheria after the 60 units and had a mild attack, neverthe less 150 units should be given. When infection is virulent, 600 units: a full curative dose. Several doses at inter vals more serviceable than a single large dose. Behring (Deutsche med. Woch., Nov. 15, '04).
Quantity required in a case varies from 1000 to 4000 units of Behring's standard, according to the weight of pa tient and severity of the disease. W. II. Park (Med. Fortnightly, Dec. 2, '95).
From 1 V, to 21/2 drachms are enough for benign cases taken at the onset; 4 to 6 drachms in severe cases or when they have passed several days; up to 1 ounce or even beyond in very severe cases. When breathing is embarrassed tracheotomy may be rendered unneces sary by an injection of 4 to 6 drachms, followed by another of from 2 '/2 to 4 drachms if improvement is not satisfac tory. Better to inject at onset a dose
of serum stronger than necessary, cut ting short the malady rather than to inject weak doses at intervals. In in fants under 1 year old as many as 15 minims may be injected as the child numbers months. In adults not neces sary, unless case extremely grave, to inject more than 4 to 6 drachms the first time. Roux (Med. Press and Circular, -Mar. 20, '95).
That 600 units the most beneficial dose proved by the collective investigation of the Deutsche medicinische 1Vochenschrift, bearing upon 10,312 cases. Average per centage of 6 per cent. of deaths when 600 units used, average percentage of 14.6 when 1000 units used. (Annual, '96).
Observation on a series of cases of diphtheria that occurred in hospital, a wide-spread epidemic being imminent. In this outbreak none of the children was removed, but all that had been in any way exposed, 110 in number, were promptly immunized. The doses admin istered ranged from 250 to 500 units, according to age of child. Four or five of these children had sore throats with small patches on the following day. Each of these and all that had already developed the disease received 1000 units each. The result was a prompt recovery in every instance and no new cases have appeared in the institution since.
About same time 41 cases of diph theria appeared in rapid succession in another institution. All were more or less complicated with measles and scar let fever. Four initial cases did not receive the serum-treatment and all died. The remaining 37 cases received anti toxin treatment and but 2 died. Deduct. ing the fatal cases, without a single ex ception, the 174 antitoxin-treated cases developed no sequelee, either those re ceiving curative or immunizing doses. J. H. Lopez (Med. News, Jnly 30, '93).
Children under eight years of age are given an initial dose of 500 immunizing units, to be repeated at intervals of six hours if the fever does not fall, if the strength of the patient does not improve, or if the local manifestations are spread ing. To children over eight years of age, 1000 immunizing units are given as an initial dose, and repeated at intervals of eight to twelve hours if necessary. J. H. Musser (Univ. Med. Mag., Mar., 1900).
For fifteen years before the diphtheria antitoxin was used the average number of deaths yearly AN as 2373; for the four years since the use of antitoxin the average was 1341. In mild cases, seen early, 1000 units are recommended; in mild eases, seen late, 1000 to 2000 units; in severe cases, seen early, from 2000 to 4000 units; and in severe cases, seen late, an initial dose of not less than 3000 or 4000 units. W. H. Park (Phila. Med. Jour., Mar. 31, 1900).