Objective: To characterise the pharmacokinetics of adenosine 5'-triphosphat
e (ATP) in patients with lung cancer after i.v. administration of different
ATP dosages.
Methods: Twenty-eight patients received a total of 176 i.v. ATP courses of
30 h. Fifty-two infusions were given as low-dose infusions of 25-40 mu g kg
(-1) min(-1), 47 as middle-dose infusions of 45-60 mu g kg(-1) min(-1) and
77 as high-dose infusions of 65-75 mu g kg(-1) min(-1) ATP. Kinetic data of
ATP concentrations in erythrocytes were available from 124 ATP courses. Re
sults are expressed as mean +/- SEM.
Results: Most ATP courses in cancer patients were without side effects (64%
), and side effects occurring in the remaining courses were mild and transi
ent, resolving within minutes after decreasing the infusion rate. Baseline
ATP concentration in erythrocytes was 1554 +/- 51 mu mol l(-1) ATP plateau
levels at 24 h were significantly increased by 53 +/- 3, 56 +/- 3 and 69 +/
- 2% after low-dose, middle-dose and high-dose ATP infusions, respectively.
At the same time, significant increases in plasma uric acid concentrations
were observed: 0.06 +/- 0.01, 0.11 +/- 0.01 and 0.16 +/- 0.01 mmol l(-1),
respectively. The mean half-time for disappearance of ATP from erythrocytes
, measured in five patients, was 5.9 +/- 0.5 h.
Conclusions: During constant i.v. infusion of ATP in lung cancer patients,
ATP is taken up by erythrocytes and reaches dose-dependent plateau levels 5
0-70% above basal concentrations at approximately 24 h.