Like many kids, I was plagued with regular strep throat infections. And, like some kids, my penicillin allergy prevented me from taking the first-line antibiotics to treat those illnesses. So, like many—probably too many—kids and adults, I got Z-Pack antibiotics. Now, decades later, I’m sad to say that basically never happens.
Unlike other antibiotics that were usually difficult for me to take as a kid and required multiple doses a day for 10 days or more, Z-Packs only required a breezy five-day course of small, often pink pills. When I got a Z-Pack, I wasn’t exactly happy, but I felt like the end to my misery was just a few days away. It was a solution—and I knew relief would come relatively quickly.
Z-Pack antibiotics, we were told, were safe and effective at treating approximately a billion different conditions. So, what happened to Z-Packs? And why am I stuck with long, boring courses of other antibiotics these days instead? As it turns out, there are some pretty good reasons.
Wait, remind me what Z-Packs are?
A Z-Pack (also called a Z-Pak, Zmax, or Zithromax) is literally just azithromycin, a standard antibiotic introduced in 1992, formulated in a package of six pills, which are taken over five days.
That short time commitment was a huge part of their appeal. Other antibiotics may require multiple doses a day for 10 or 14 days at a time, Tara Vijayan, M.D., assistant clinical professor in the Division of Infectious Diseases at the David Geffen School of Medicine at UCLA, tells SELF. “The Z-Pack was a nice defined course and relatively short,” she says. “It made people feel like they can do this; they can complete their course and they’ll be done with it.”
Plus, the ones I took were usually hot pink and came in a blister pack rather than a bottle—factors that mattered a lot to a sick and miserable 8-year-old me. They were “cheap, easy, cute, and they had a little marketing zing,” Neha Vyas, M.D., a family medicine physician at Cleveland Clinic, tells SELF.
And, Dr. Vyas says, they’re indicated for a bunch of different health issues (including skin infections, sinus infections, pharyngitis, and gonorrhea), which made them an appealing option when the first-line treatments weren’t available. For instance, before azithromycin, if you had a penicillin allergy and needed an antibiotic for a case of strep throat, your only option was likely a cephalosporin antibiotic, which still has some cross-reactivity with penicillin allergies, Dr. Vyas explains. So, if there were any worries about allergies, a Z-Pack was an obvious, nearly all-purpose choice.
So, what happened to Z-Packs?
To be clear, nothing really happened to Z-Packs specifically, Dr. Vyas says. They’re still around and still frequently prescribed to treat a few specific conditions. But lots of things happened around Z-Packs over the last several years that made doctors realize that their prescribing practices weren’t quite right.
In fact, in many ways, the rise and fall of the Z-Pack is simply a reflection of the way our understanding of antibiotics as a whole has developed in the past decade. We now know so much more about which antibiotics are best used for which illnesses, how the overuse (and misuse) of antibiotics contributes to antibiotic resistance, and the what the optimal time course is for various antibiotics. All of this resulted in Z-Packs becoming a bit less unique and less suited for some common illnesses.
The first big factor in the waning of Z-Pack popularity was that our developing understanding of antibiotic resistance made doctors wary about handing out Z-Packs so frequently for seemingly every minor health issue that might have a bacterial cause. They were being given out “like candy,” Dr. Vyas says.
Antibiotic resistance, which the World Health Organization says is “one of the biggest threats to global health, food security, and development today,” occurs when bacteria become resistant to the drugs we use to treat bacterial infections. The exact way that bacteria become resistant to a drug like azithromycin is complex, but Dr. Vijayan says the basic gist is that already-resistant bacteria exist in small numbers. When antibiotics are overused or misused, we eliminate the bacteria that aren’t resistant, leaving the resistant bacteria to spread—and to spread their resisting abilities to other bacteria.
When bacteria are resistant to a medication, doctors need to use a different antibiotic to treat the infection. That’s concerning because we have a limited number of antibiotic options available. And the ones we can use against antibiotic-resistant strains can cause serious side effects or aren’t necessarily the best options to use (still, they are better than nothing).
At this point, research estimates that up to 98 percent of group A streptococcus (the bacteria that causes strep throat) are resistant to azithromycin worldwide, Dr. Vijayan says. In the U.S., estimates are lower but not great (usually between 3 and 15 percent, but have been reported as high as 48 percent). So, no, a Z-Pack is not the first-line option for strep throat, even if it’s easy.
Z-Packs are associated with both mild and serious side effects.
“In addition to the emerging resistance,” Dr. Vijayan says, “nobody fully appreciated the side effects of these medications until we had a lot of post-marketing data.” In particular, she says, a study published in 2012 in the New England Journal of Medicine looking at 14 years worth of data showed that taking a five-day treatment with azithromycin—essentially a Z-Pack—was correlated with an increased risk for two serious cardiac issues. The data included nearly 350,000 patients who took a five-day course of azithromycin and about 1.4 million matched control periods (time periods during which control participants weren’t taking any antibiotics included in the study).
There were 29 cardiovascular deaths among those taking azithromycin, 22 of which were sudden cardiac deaths, which was estimated to equal about 64 deaths for every million prescriptions. Among the control participants, there were 41 cardiovascular deaths, 33 of which were sudden cardiac deaths. That amounted to 24 deaths for every million control periods.
The link between azithromycin and heart issues wasn’t new, but out of this data, “azithromycin emerged as one of the drugs that had a relatively high incidence of sudden cardiac death,” Dr. Vijayan says. The thought with Z-Packs had been that, it was such a short time course that it wouldn’t have been enough to cause the more serious issues associated with azithromycin, she explains, but this study suggested otherwise.
Although the study only showed a correlation between taking the medication and sudden cardiac deaths, not a causal relationship, it was enough for the FDA to release a warning, and for doctors to take another look at their prescribing habits around azithromycin.
And, to be clear, Z-Packs do still come with many of the same side effects you’d expect with other antibiotics, Dr. Vyas says, including diarrhea and nausea. “There’s no such thing as a completely harmless antibiotic,” she says.
There’s more nuance to antibiotic prescribing than you might realize.
The way doctors think about prescribing all antibiotics—not just Z-Packs—has evolved since these medications were introducted.
First off, both of the experts SELF spoke to for this story emphasize that what may seem like a penicillin allergy—or, more likely, what you’ve been told all your life is a penicillin allergy—may not be a true allergy. Many people, like me, grow up being told that they had some kind of a rash or other vaguely bad reaction after getting penicillin treatment as a baby, which is very possibly true. But people grow out of these sorts of reactions, Dr. Vijayan says, and doctors now appreciate just how exceptionally rare true penicillin allergies are.
About 10 percent of patients report a penicillin allergy, according to estimates from the American Academy of Allergy, Asthma, and Immunology (AAAI), but about 90 percent of them may not actually have one. So, many of the people who took Z-Packs because they thought it was their only option may have been perfectly fine just getting the penicillin instead, making them even more egregiously overprescribed.
That’s why Dr. Vijayan—and the AAAI—emphasize the importance of getting a penicillin allergy test, which, depending on your circumstances, could involve taking a pill in your doctor’s office or a more formal skin test under supervision. Considering what valuable and effective tools penicillin and its related antibiotics are (there are now many derivatives of penicillin that build on the original formulas to better target specific bacterial vulnerabilities), it would be a real shame to continue avoiding these first-line treatments due to unfounded concerns.
We’ve also come to understand that there are shades of gray to the conventional wisdom of taking every last dose of your antibiotic, even if you feel better long before that, Dr. Vijayan says. The truth is that, for many antibiotics that are routinely prescribed in primary care, a shorter course is totally fine—sometimes even better—than a longer one.
Part of the reason for that is simple: “We know the longer the duration of treatment and the more times a day you take it, the less compliant patients will be,” Dr. Vyas says. But there are also other complexities here, Dr. Vijayan explains, like the fact that, in some cases, a shorter duration could actually reduce the likelihood of antibiotic resistance developing. So, the novelty of the Z-pack’s short course is kind of lost today. “Any number of drugs would be fine in the same duration,” Dr. Vijayan says.
Of course, you should always follow your doctor’s instructions for taking your antibiotics, but it’s OK to ask them about the recommended duration of treatment and how you should react if you start feeling better before you’re done.
And, hey, you might still get prescribed a Z-Pack occasionally.
There are still solid uses for azithromycin, including the treatment of chlamydia, Dr. Vijayan says. So, if you’ve been prescribed the antibiotic, know that your doctor likely has a good reason for it.
However, today, it’s unlikely you’ll get a Z-Pack for a sinus infection, strep throat, or a nondescript upper respiratory infection (unless you have a well-documented penicillin allergy) for a few different reasons. First off, remember that not all illnesses that cause symptoms like a sore throat are bacterial—they are far more likely to be due to a viral infection, meaning no antibiotic on earth will help you.
Second, remember that illnesses like these go away on their own, but some symptoms—like a lingering cough, for instance—may take a really, really long time to do so (like, a few weeks even). That might make you think your random cold has graduated to the level of, say, bronchitis, and therefore you deserve some meds. But a long illness doesn’t necessarily mean you need antibiotics. “The reality is that [these illnesses] just take time,” Dr. Vijayan says, “and it’s hard to hear that and not hope for a quick fix.”
And, lastly, even if you do have an illness that would have gotten you an easy Z-Pack prescription a few years ago, Dr. Vijayan says that doctors today are encouraged to be more selective when prescribing the right antibiotic for each patient’s illness—even if penicillin isn’t an option. A case of strep throat might require clindamycin, for instance, or you might get a cephalosporin like cefadroxil as recent research suggests the risk for cross-reactivity with penicillin allergies is much less than originally thought.
Gone are the days of getting a Z-Pack for every sore throat or sinus infection and, actually, I’m pretty OK with that. It turns out we don’t need antibiotics as often as we might think. And when we do need an antibiotic, there is no one-size-fits-all approach. Obviously, you can check in with a doctor to see if you would or wouldn’t benefit from taking an antibiotic for your illness, but it’s also important to be open to the possibility that you’re just going to feel sick—like, for a while. And, sadly, a five-day course of bright pink pills isn’t likely to fix that.