Disposition of nebulized pentamidine measured using the direct radiolabel 123I-iodopentamidine.
The pulmonary deposition of nebulized pentamidine (300 mg, Respirgard II nebulizer) was measured in seven human immunodeficiency virus (HIV)-positive men using a new radiopharmaceutical, 123I-iodopentamidine. Mean total pulmonary deposition was 15.3 mg or 5.1% of the initial nebulizer dose. Further studies in two of the patients showed that at 24 h, 87% of deposited 123I was retained in the lungs. Small amounts of activity (expressed as a percentage of the initial nebulizer activity) were also detected over the thyroid (0.4%), bladder (1%) and gut (0.7%). The ratio of 123I activity to pentamidine concentration was similar in the nebulizer solution and urine. These results suggest that 123I-pentamidine may be sufficiently stable in vivo to be used to study the biodistribution of inhaled and parenteral pentamidine in humans.
O'Doherty
M J
MJ
Department of Nuclear Medicine, St. Thomas' Hospital, London, UK.
Thomas
S H
SH
Page
C J
CJ
Blower
P J
PJ
Bateman
N T
NT
Nunan
T O
TO
D000280:Administration, Inhalation; D000328:Adult; D006679:HIV Seropositivity / Q000188:drug therapy*; D006801:Humans; D007457:Iodine Radioisotopes; D007553:Isotope Labeling; D008297:Male; D009330:Nebulizers and Vaporizers; D010419:Pentamidine / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use
D007457:Iodine Radioisotopes; D010419:Pentamidine