676 ACTIVE IMMUNIZATION 



to be avoided, and no great advantage is to be gained from using intra- 

 venous injections. 



Time of Injection. There is some difference of opinion as to the best 

 time of the day for administering tuberculin therapeutically. If given 

 in the morning, a slight febrile reaction may occur during the evening 

 which would otherwise be overlooked. Brown is in favor of the after- 

 noon as the most suitable time, because it affords an opportunity for 

 omitting the dose in case there is an accidental rise of temperature on 

 that day. On the other hand, it is contended that the rest at night 

 would tend to prevent the occurrence of the reactions that might appear 

 if the patient were up and about. 



While it is not essential that the patient rest for a few hours after a 

 dose has been administered, this is advisable, and where absolute rest 

 can be enforced, the dosage may be increased with greater rapidity than 

 in ambulant patients. 



Interval Between Doses. The interval between injections is usually 

 from three to four days i. e. } two injections a week. This interval is 

 merely tentative, and while it should not be shortened, it may be nec- 

 essary to prolong it. While most reactions set in within from twenty- 

 four to thirty-six hours, some may begin as late as from forty-eight to 

 sixty hours (L. Brown). By waiting at least three days we may be 

 assured that, if no reaction has occurred, none will take place. 



The usual interval is maintained as long as the patient is doing well. 

 After a while the patient becomes intolerant and exhibits slight reac- 

 tions, depression, and loss of weight. In such instances the interval may 

 be increased to a week and the injections continued. Hamman and Wol- 

 man find this occurrence so frequent that they advise creasing the 

 dose interval to one week, when the dose of 100 mg. of O. T. is reached, 

 200 mg. of T. R. and B. E., and 50 mg. of B. F. 



2. Other Routes for the Administration of Tuberculin. Oral 

 Route. It has been shown that reactions may follow the oral 

 administration of tuberculin. But absorption is so irregular that a 

 quantity of tuberculin may be absorbed suddenly and cause unexpected 

 reactions. Much depends, apparently, upon the state of digestion 

 and upon the condition of the alimentary tract. The oral route also 

 deprives the physician of the benefits to be obtained from using the local 

 reaction as a guide. Otherwise the method is simple and the tuber- 

 culin may be administered in the form of tablets or in capsules. It 

 is important, however, to exercise supervision over the patient. S. 



