Does PrEP Have Side Effects?

Published: December 6, 2012

I brought my pills to work for three days while waiting for my HIV test results. I was eager to start taking Truvada for PrEP, but I knew that I needed to wait for my HIV test results to come back to confirm that I was HIV-negative before I began popping them. My doctor had gone ahead and written me a prescription when I had my blood drawn – before my test results had come back.

I went straight from my doctor’s office to the pharmacy to drop off my prescription. I was eager to get my hands on those pills – in part because I didn’t know if my insurance would cover them. It was only later, when doing research for this column, that I learned that insurance companies have been extremely good at covering PrEP.

The call with my negative result came on an ordinary afternoon while I was working on a project with a friend. I wasted no time, heading directly to the water fountain to wash down the first of many blue pills. I came back to my desk distracted. I was waiting… for what, exactly? Side effects? The feeling of being 92% less likely to contract HIV?

I’ve received a lot of emails from readers inquiring about what side effects I experienced when I started taking PrEP. That day at the office, I was anxiously awaiting the answer. I’ve been taking Truvada for three months now, and the honest answer is that I haven’t experienced any noticeable side effects since.

As it turns out, I’m like most people in that regard. Let’s revisit the iPrEX study results to get a sense of what side-effects participants reported in the original PrEP study. These fell into four main categories, ordered here in most to least common:

  1. Nausea: 9% of those who received Truvada reported nausea in the first month, compared to 5% of those who received placebo. After the first month, there was no difference in reported rates of nausea among those who received Truvada and those who received a placebo.
  2. Headaches: 4.5% of participants who received Truvada reported 66 headache events, as compared to 3.3% of those who received the placebo that reported 55 headache events.
  3.  Weight Loss: 2.2% of those who received Truvada reported unintentional weight loss of more than 5%, compared with 1.1% of placebo users
  4. Small Increases in Serum Creatinine: Truvada is known to cause small increases in serum creatinine, a naturally occurring molecule filtered by the kidneys. In this study, 0.3% of those who received Truvada experienced mild increases in serum creatinine that persisted until the next test. All creatinine elevations resolved with discontinuation of the pill. Four of the 5 participants restarted PrEP without recurrence of the creatinine increase. Investigators monitored renal function throughout the study and found no serious kidney problems.

I was bummed to not have experienced any unintentional weight loss, but I was otherwise thankful to skip the nausea and headaches. Readers have been bombarding me with questions, though, asking if I’ve experienced all kinds of wild side effects that have never been associated with Truvada. Many people simply assume that all HIV drugs are one and the same; they’ve seen movies depicting awful side effects like lipodystrophy or extreme fatigue, and they assume that Truvada is just as likely to cause those problems as other drugs. But not all HIV drugs are the same. While some drugs used to treat HIV do cause more severe problems, most people who take Truvada do not experience side effects and, for those who do, they are generally mild. That’s why Truvada was an obvious choice for scientists who sat down to figure out which HIV drug would be a good candidate for PrEP.

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