A generally quiet debate over whether a daily dose of a drug called Truvada can really protect an HIV negative person from contracting the disease that causes AIDS has reached a flash point.

Michael Weinstein, president of AIDS Healthcare Foundation, recently described Truvada as a “party drug” in an interview with the Associated Press. (Weinstein’s full quote was: “If something comes along that’s better than condoms, I’m all for it, but Truvada is not that. Let’s be honest: It’s a party drug.”)

That prompted an attack on Weinstein by Michael Lucas, a porn performer and adult movie producer, in an article published in Out magazine. Today Eric Paul Leue, recently named Mr. Los Angeles Leather and, coincidentally, a figure in a current AHF ad campaign, says he is launching a petition drive to demand that Weinstein resign from AHF, which he founded in 1987. AHF is the world’s largest non-government provider of HIV/AIDS healthcare services. It is based in Los Angeles and operates in 33 countries.

Truvada, which is manufactured by Gilead Science, is a pill that contains two drugs: tenofovir disoproxil fumarate and emtricitabine. Its use is described as “pre-exposure prophylaxis” (PreP), a term that describes a way to prevent contracting a disease. Truvada was approved by the Food and Drug Administration in 2004 for treatment of HIV infection. In 2012 Gilead won permission to market it as a drug to prevent contracting HIV.

Since 2012 a war has slowly begun between those who see condoms as the only effective way to prevent someone not in a monogamous relationship from contracting HIV and those who argue that PreP is the future in a world where use of condoms is on the decline. Weinstein’s use of the term “party drug,” an allusion to the recreational use by many gay men of dangerous and illegal substances such as GHB and crystal meth, was a flashpoint that will draw wider attention to a fight that largely has been waged on blogs devoted to gay health.

The condom has been pretty much the only form of HIV prevention since the advent of AIDS in the United States in the 1980s. Studies by the U.S. Centers for Disease Control (CDC) describe a latex condom as providing an “impermeable barrier” to the HIV virus and to bacteria associated with other sexually transmitted diseases such as syphilis and gonorrhea.

The effectiveness of condoms in preventing transmission of HIV and other sexually transmitted diseases is often misunderstood because of the way the data is presented. For example, some studies say that condoms are 60 to 70 percent effective in preventing HIV transmission, a statistic that Truvada proponents have used in arguing that the drug is more effective. But those studies include people who don’t use a condom consistently. Studies show condoms are 90 to 95 percent effective in preventing HIV transmission if used consistently, but even those studies don’t account for instances where someone puts a condom on incorrectly so that it slips off or uses it in such a way that it tears.

One study suggests that the best predictor that a gay man will use a condom effectively is the fact that he has had sex at least 10 times a year and thus knows how to put one on. The fact that a latex condom is described as “impermeable” suggests it is 100 percent effective if used consistently and correctly. One indicator of the power of the condom is a study by the UK’s Health Protection Agency that estimated HIV transmission rates in 2000 would have been 400 percent higher if all gay and bisexual men had stopped using them.

The fact is, however, that consistent use of condoms is on the decline among gay men. The CDC reported last November than incidents of gay and bisexual men having unprotected sex with other men increased 20 percent from 2005 to 2011. The reasons aren’t clear. Some speculate that many gay men are willing to risk contracting HIV because it’s no longer viewed as a fatal disease. Others say that a new generation of gay men is unfamiliar with the fatal consequences of HIV in the 1980s and 1990s that led to a dramatic increase in condom use.

Advocates of Truvada as PreP fall into two camps. There are those who support it so long as the men taking the drug also use a condom (the rationale is that someone who is under the influence of alcohol or drugs may forget to use a condom sometimes, and Truvda reduces the risk in those situations). There also are those who see Truvada as a substitute for condoms.

One argument among the latter group is that gay men are going to have unprotected sex anyway, so why not offer Truvada to reduce the risk of HIV transmission (it doesn’t reduce the risk of contracting other sexually transmitted diseases).

Some point to studies that show Truvada’s effectiveness, often misinterpreting the figures. In his essay in Out magazine, Michael Lucas says “the latest research shows that people who take PrEP on a daily basis achieve upwards of 90 percent protection from the virus. That’s a conservative estimate. In the largest study to date, not a single person who took PrEP as prescribed became HIV positive.” Lucas does note, in another essay published in Out in July, that he takes Truvada and that it is important to also use a condom when having sex.

The results of the studies, all of which show daily use of Truvada helps reduce the risk of HIV infection, are complex. The study cited by Lucas actually shows a 99 percent reduction in the risk of contracting HIV in men whose blood shows a level of Truvada that suggests they take it every day. But those men also were offered a package of prevention services that included condoms, monthly HIV testing and counseling to reduce risky sexual behavior and encourage daily use of Truvada. So while Truvada clearly did reduce the risk of HIV infection, it isn’t clear what impact condom use also had on that reduction.

Even some PreP advocates worry that HIV negative gay men may not take a Truvada pill every day. “In a majority of PrEP studies, many or most people did not take it as directed,” noted a writer for BetaBlog.org who was covering a conference on the subject at a San Francisco provider of sexual health services. “Some people are also fearful about PrEP after seeing the debilitating side effects of older antiretroviral drugs.” There is evidence that the drug can cause a reduction in bone density in some people, which has emerged, along with a higher risk of heart disease, as an issue for some people who have been taking antiretroviral medication for HIV over the years.

For some men, a factor in adherence to the daily Truvada regimen may be the cost of the drug, which can be as much as $1,000 a month, although some insurance plans cover much of that. Another is what researchers call the “seasons of risk” for gay men. In those periods when an HIV negative man is in a monogamous relationship with another HIV negative man or is not having sex at all, he may be disinclined to take Truvada every day. But then he may quickly move overnight into a “season of risk” without having the drug on hand or a sufficient amount of it in his system to help protect him.

There’s little chance that Lucas and Leue’s petitions will force Michael Weinstein to leave AHF. But perhaps bringing the debate forward will prompt a deeper look at the potential risks and rewards of Truvada and a deeper look at the scientific studies, whose abstracts often are all that are read, and quoted, by adherents of one approach or another.