Tennessee Subscriber
Answer: If you want to report the physician's administration of the medication, you could use an E/M code, such as 99214 (Office or other outpatient visit for the E/M of an established patient ...). Also, you can bill a J code, such as J0170 (Injection, adrenaline, epinephrine, up to 1 ml ampule).
And, you may assign codes +99354 (Prolonged physician service in the office or other outpatient setting requiring direct [face-to-face] patient contact beyond the usual service [e.g., prolonged care and treatment of an acute asthmatic patient in an outpatient setting]; first hour [list separately in addition to code for office or other outpatient evaluation and management service]) and +99355 (... each additional 30 minutes [list separately in addition to code for prolonged physician service]).
But before using these codes, you should know how to calculate your time - which might be harder than you think. CPT assigns each office or other outpatient E/M code (99201-99215) a typical time for completing the service. When you use the prolonged service codes, you must subtract the stated E/M time (25 minutes) from the amount of time your physician treated the patient (two hours). For an additional 30 minutes (99355), you must add that time with the initial E/M code and subtract 55 minutes from the total time spent.