Final answer:
Adenosine should be administered as a rapid IV bolus of 6mg initially, and if necessary, a follow-up dose of 12mg. The administration must be followed by a normal saline flush and requires close monitoring of cardiac and hemodynamic responses.
Step-by-step explanation:
When a 24-year-old female patient is experiencing a regular narrow complex tachycardia with a rate of 192 beats per minute (bpm), adenosine should be administered quickly due to its short half-life. Adenosine is typically given as a rapid intravenous (IV) bolus. The initial recommended dose is 6mg given rapidly over 1-2 seconds through an IV line, followed by a flush of normal saline to push the medication into the central circulation. If this does not terminate the tachycardia, a 12mg dose can be given 1 to 2 minutes later, following the same procedure. Close monitoring of the patient's heart rate, rhythm, and blood pressure is essential during the administration of adenosine, as the medication can cause transient arrhythmias as it slows conduction through the AV node.