TY - JOUR
T1 - Isoosmolar Enemas Demonstrate Preferential Gastrointestinal Distribution, Safety, and Acceptability Compared with Hyperosmolar and Hypoosmolar Enemas as a Potential Delivery Vehicle for Rectal Microbicides
AU - Leyva, Francisco J.
AU - Bakshi, Rahul P.
AU - Fuchs, Edward J.
AU - Li, Liye
AU - Caffo, Brian S.
AU - Goldsmith, Arthur J.
AU - Ventuneac, Ana
AU - Carballo-Diéguez, Alex
AU - Du, Yong
AU - Leal, Jeffrey P.
AU - Lee, Linda A.
AU - Torbenson, Michael S.
AU - Hendrix, Craig W.
PY - 2013
Y1 - 2013
N2 - Rectally applied antiretroviral microbicides for preexposure prophylaxis (PrEP) of HIV infection are currently in development. Since enemas (rectal douches) are commonly used by men who have sex with men prior to receptive anal intercourse, a microbicide enema could enhance PrEP adherence by fitting seamlessly within the usual sexual practices. We assessed the distribution, safety, and acceptability of three enema types - hyperosmolar (Fleet), hypoosmolar (distilled water), and isoosmolar (Normosol-R) - in a crossover design. Nine men received each enema type in random order. Enemas were radiolabeled [99mTc-diethylene triamine pentaacetic acid (DTPA)] to assess enema distribution in the colon using single photon emission computed tomography/computed tomography (SPECT/CT) imaging. Plasma 99mTc-DTPA indicated mucosal permeability. Sigmoidoscopic colon tissue biopsies were taken to assess injury as well as tissue penetration of the 99mTc-DTPA. Acceptability was assessed after each product use and at the end of the study. SPECT/CT imaging showed that the isoosmolar enema had greater proximal colonic distribution (up to the splenic flexure) and greater luminal and colon tissue concentrations of 99mTc-DTPA when compared to the other enemas (p<0.01). Colon biopsies also showed that only the hyperosmolar enema caused sloughing of the colonic epithelium (p<0.05). In permeability testing, the hypoosmolar enema had higher plasma 99mTc-DTPA 24-h area under the concentration-time curve and peak concentration compared to the hyperosmolar and isoosmolar enemas, respectively. Acceptability was generally good with no clear preferences among the three enema types. The isoosmolar enema was superior or similar to the other enemas in all categories and is a good candidate for further development as a rectal microbicide vehicle.
AB - Rectally applied antiretroviral microbicides for preexposure prophylaxis (PrEP) of HIV infection are currently in development. Since enemas (rectal douches) are commonly used by men who have sex with men prior to receptive anal intercourse, a microbicide enema could enhance PrEP adherence by fitting seamlessly within the usual sexual practices. We assessed the distribution, safety, and acceptability of three enema types - hyperosmolar (Fleet), hypoosmolar (distilled water), and isoosmolar (Normosol-R) - in a crossover design. Nine men received each enema type in random order. Enemas were radiolabeled [99mTc-diethylene triamine pentaacetic acid (DTPA)] to assess enema distribution in the colon using single photon emission computed tomography/computed tomography (SPECT/CT) imaging. Plasma 99mTc-DTPA indicated mucosal permeability. Sigmoidoscopic colon tissue biopsies were taken to assess injury as well as tissue penetration of the 99mTc-DTPA. Acceptability was assessed after each product use and at the end of the study. SPECT/CT imaging showed that the isoosmolar enema had greater proximal colonic distribution (up to the splenic flexure) and greater luminal and colon tissue concentrations of 99mTc-DTPA when compared to the other enemas (p<0.01). Colon biopsies also showed that only the hyperosmolar enema caused sloughing of the colonic epithelium (p<0.05). In permeability testing, the hypoosmolar enema had higher plasma 99mTc-DTPA 24-h area under the concentration-time curve and peak concentration compared to the hyperosmolar and isoosmolar enemas, respectively. Acceptability was generally good with no clear preferences among the three enema types. The isoosmolar enema was superior or similar to the other enemas in all categories and is a good candidate for further development as a rectal microbicide vehicle.
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U2 - 10.1089/aid.2013.0189
DO - 10.1089/aid.2013.0189
M3 - Article
C2 - 23885722
AN - SCOPUS:84886689213
SN - 0889-2229
VL - 29
SP - 1487
EP - 1495
JO - AIDS research and human retroviruses
JF - AIDS research and human retroviruses
IS - 11
ER -