Clinical application of diadenosine tetraphosphate(Ap 4 A:F‐1500) for controlled hypotension

Background: In our animal study, it was revealed that diadenosine tetraphosphate (Ap 4 A:F‐1500) has a dose‐dependent hypotension effect of up to 60% decrease in mean arterial pressure compared to control value. Furthermore, in healthy male volunteers, the safety of Ap 4 A up to 4 mg · min −1 was confirmed. In patients who require surgical procedures under general anesthesia together with controlled hypotension, hypotension was induced by Ap 4 A in order to examine its hypotensive effect and modulating action on the blood pressure. Methods: Ten patients who required controlled hypotension and who were scheduled for elective surgery under general anesthesia were studied. Anesthesia was maintained with isoflurane (n=7) or sevoflurane (n=3) in oxygen‐nitrous oxide. Controlled hypotension was induced by Ap 4 A administered at a rate of 10–20 μg · kg −1  · min −1 . The dose was adjusted at a maximum rate of 80 μg · kg −1  · min −1 until the target blood pressure was achieved. Arterial blood pressure and heart rate were monitored. Arterial samples were drawn at 4 separate time points to measure the concentration of Ap 4 A in the plasma. Results: The time required for attaining the target blood pressure after initiation of Ap 4 A infusion was about 16 min, and the time lapse between withdrawal of infusion to recovery of blood pressure was about 18 min. No reflex tachycardia was observed during infusion of Ap 4 A and no rebound hypertension was evident after withdrawal. The plasma Ap 4 A concentration increased in response to the acceleration rate of Ap 4 A administration with a tendency of augmented hypotensive effect. Conclusion: As it produces an excellent hypotensive effect together with a modulating action on blood pressure, Ap 4 A was assessed as useful in producing controlled hypotension.