[Influence of peplomycin on pulmonary function (PaO2, %DLco) in patients with oral carcinoma]

The pathogenesis of pulmonary fibrosis (PF) induced by bleomycin and its derivative, peplomycin (PEP), is insufficiently understood. To prevent PF and to administer PEP safely, we examined the influence of PEP on pulmonary function in 135 patients who underwent concomitant chemo (PEP + 5-FU)-radio (60Co) therapy and pulmonary function tests. In the inductive therapy, 5 mg of PEP was intramuscularly injected three times a week and a total of 41.6 +/- 14.3 mg was administered. Of the patients, 98 received oral azelastine hydrochloride (AZH, 4 mg/day) during the inductive therapy with the aim of prophylaxis of PF. The oxygen partial pressure in arterial blood (PaO2) only slightly decreased from 84.2 +/- 12.1 mmHg before treatment to 82.8 +/- 12.5 mmHg after treatment, while, carbon oxide diffusion (%DLco) decreased after treatment in most patients (p < 0.001, by paired t test) with mean values before treatment of 106.3 +/- 24.5% and after treatment 99.5 +/- 24.9%. The decrease of %DLco was associated with the dose of PEP until about 40 mg but further decreases of %DLco were not prominent. In the patients who underwent oral AZH, the decrease of %DLco weaker than that in patients without AZH: the decrease rates of %DLco in the former and latter were 4.3 +/- 9.4% and 14.1 +/- 15.9%, respectively. From the chest X-ray examination, mild PF was suspected in three patients but no advancement of PF or clinical symptoms were observed. From these results, it was concluded first that %DLco is more useful than PaO2 as the predisposing risk factor for PF, second that the decrease of %DLco depends on the dose of PEP until about 40 mg, third that AZH is expected to inhibit PEP-induced PF, and fourth that a small dose (20-40 mg) of PEP can be administered without inducing PF if care is exercised as to the patient's age, general condition and the value of %DLco in the use of PEP.