Document 0486
 DOCN  M9440486
 TI    Regional deposition and regional ventilation during inhalation of
       pentamidine.
 DT    9404
 AU    O'Riordan TG; Smaldone GC; Division of Pulmonary/Critical Care Medicine,
       State University of; New York at Stony Brook.
 SO    Chest. 1994 Feb;105(2):396-401. Unique Identifier : AIDSLINE
       MED/94139391
 AB    In most patients, the deposition of aerosolized pentamidine (AP) is less
       in the apex of the lung relative to the base. As the apex of the lung is
       relatively less ventilated than the base, it is possible that reduced
       regional ventilation may explain the inhomogeneity in regional drug
       deposition. The purpose of this study was to measure the relationship
       between regional deposition of AP and regional ventilation, and the
       influence of particle size and airway caliber on this relationship. Ten
       subjects with HIV infection who were receiving prophylaxis with AP were
       recruited. Using krypton (81mKr), we measured regional ventilation
       during treatment with AP, labeled with 99mTc. Two nebulizers were used
       (Respirgard II and Fisoneb) that produced particles of different size.
       In addition, patients were studied with and without a bronchodilator
       because changes in airway geometry can affect sites of particle
       deposition. There was no significant correlation between regional
       ventilation and regional particle deposition (r = 0.00, linear
       regression). Particle deposition in the upper lobes relative to the
       lower lobes was less than would be predicted by regional ventilation, by
       a ratio of 0.84 +/- 0.03 (mean +/- SE). Using two-way analysis of
       variance (ANOVA), the upper to lower zone deposition pattern was not
       affected by either nebulizer or by the use of albuterol. The Fisoneb had
       significantly more central deposition relative to the jet nebulizer
       (mean +/- SE, skC/P: Fisoneb 1.3 +/- 0.1, Respirgard 1.1 +/- 0.1, p =
       0.005, two-way ANOVA). The use of a bronchodilator did not significantly
       affect the central/peripheral deposition pattern. We conclude that
       differences in deposition between upper and lower lung regions are not
       accounted for simply by differences in regional ventilation in patients
       undergoing prophylaxis with AP. In assessing the cause of regional
       inhomogeneities of pharmaceutical aerosol deposition (and in devising
       strategies to achieve more uniform distribution), regional ventilation
       should be measured directly rather than be inferred from the deposition
       pattern of the aerosol.
 DE    Administration, Inhalation  Aerosols  Albuterol/ADMINISTRATION &
       DOSAGE/PHARMACOLOGY/PHARMACOKINETICS  Forced Expiratory Volume/DRUG
       EFFECTS/PHYSIOLOGY  Human  HIV Infections  Krypton
       Radioisotopes/DIAGNOSTIC USE  Lung/DRUG
       EFFECTS/*METABOLISM/*PHYSIOLOGY/RADIONUCLIDE IMAGING  Male  Nebulizers
       and Vaporizers  Particle Size  Pentamidine/*ADMINISTRATION &
       DOSAGE/PHARMACOLOGY/  *PHARMACOKINETICS  Respiration/DRUG
       EFFECTS/*PHYSIOLOGY  Support, U.S. Gov't, P.H.S.  Technetium Tc 99m
       Aggregated Albumin/DIAGNOSTIC USE  Ultrasonic Therapy/INSTRUMENTATION
       Vital Capacity/DRUG EFFECTS/PHYSIOLOGY  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).