UNIVERSAL CITY, Calif. -- Aerosolized pentamizine, widely used to prevent recurrence of a form of pneumonia that is a major killer of AIDS patients, appears to be inadequate, according to new studies at the University of Southern California.
Dr. Narsing Rao, director of Ophthalmologic Pathology at the Doheny Eye Institute in Los Angeles, yesterday urged eye exams by physicians every three months for longtime users of the therapy. Aerosolized pentamizine is inhaled into the lungs. Rao said the exams are necessary for early detection of telltale signs in the eye that the pneumonia has spread from the lungs to other organs.
"Pneumocystis carinii pneumonia is leaving the lungs and spreading to various parts of the body, just like cancer," he told a science writers' seminar here sponsored by the New York-based Research to Prevent Blindness. "Something else may be involved here. We think a better prophylaxis is needed.
"Now there are 40 cases across the country that have shown this spread. The more we look for them, the more we will find."
Widely disseminated, the pneumonia infection results in death unless patients are treated with intravenous injections of pentamizine -- a systemic treatment that reaches all parts of the body.
In earlier stages of this epidemic, advocates of patients with acquired immune deficiency syndrome fought long and hard for aerosolized pentamizine as an alternative to injected pentamide, which is much more costly and has debilitating side effects.
Since 1981, more than 20,000 cases of the pneumonia have been reported to the Centers for Disease Control in Atlanta. It is expected, he said, that by 1991, 75,000 to 100,00 cases will have been diagnosed. Sixty percent of the pnuemonia patients have recurrences unless they receive a preventive therapy.
Aerosolized pentamizine prevents recurrence in approximately 80 percent of the patients for up to one year.
"Eye changes may be the initial manifestations of disease spread, even in healthy appearing AIDS patients," Rao said. "There is no test of other clinical investigations available to detect PCP spread."
Ophthalmologists and internists should look for multiple yellowish-white white spots in the choroid, the pigmented portion of the inner eye, that are visible on examination by an eye instrument called the ophthalmoscope, he said.
While longtime aerosolized pentamizine therapy may suppress the infection sufficiently in the lungs to prevent recurrence, this treatment may be insufficient to prevent reactivation of organisms "that presumably spread outside the lungs before preventive therapy," he added.
Reactivation can occur locally in the lymph nodes and/or spleen. It can also spread to such places as the liver, bone marrow, small and large intestine, hard palate and the choroid.
In 1989, Rao reported seeing seven AIDS patients who had multiple yellowing white spots in the eye. All had a history of using aerosolized pentamine. The first three died, due to spread of pneumonia. Autopsies of these cases confirmed the spread to the eye and various other organs, including the liver, spleen and lymph nodes.
More recently, the researcher used intravenous pentamide injection to treat two more AIDS patients with disseminated pneumocystis carinii pneumonia.
"Now both patients are living more than a year," Rao said. "Once we modified the therapy we were able to control the infection and prolong life. The culprit is aerosolized pentamizine."
His findings were published last month in the American Journal of Ophthalmology. Since then, Rao said, he has heard from physicians in New York and other parts of the country who report they have seen the same spread of the infections.