What is Azithromycin used for?

6th June 2019

We’ve all heard the story of Alexander Fleming and his petri dish; having left bacteria growing, he noticed that a small patch of mould had caused a clearing of the bacterial colonies. And so was the discovery of penicillin and the birth of antibiotics as we know them.

Even though it’s possible that antibiotics have been in use for a lot longer (Ancient Egyptians used to apply mouldy bread to infected wounds, which follows the same idea), it’s something that was revolutionised in 1928 and we now have a number of different antibiotics to use on a variety of ailments.

What is Azithromycin?

Azithromycin is a macrolide-type antibiotic that can be used to treat a variety of bacterial infections but is primarily used in the treatment of sexually transmitted diseases. The most common one (bacterial and otherwise) is Chlamydia, which affects roughly 1 in 10 young people. Because this STI often has no symptoms (approximately 60% of those infected are asymptomatic), it can be a hard one to catch, but an easy one to treat.

People can often have Chlamydia for long periods of time without realising, which is why it’s important to regularly get tested either at a sexual health clinic, your GP or using an at-home test kit. This is not only to avoid the long-term risks of untreated Chlamydia (such as infertility), but also to prevent spreading it and passing it on to anyone else.

Once you test positively for Chlamydia, you will either be prescribed a 7 day, twice daily course of Doxycycline (an alternative antibiotic) or a single dose (1g) of Azithromycin. Although both qualify as first-line treatments and are both highly effective (95%), Azithromycin is often the preferred choice because of cost and the convenience of only having to take it once.

Although Chlamydia is by far the most common, it’s not the only STI that Azithromycin can be used to treat. It can also be used in the treatment of the entirely rarer, Chancroid. This genital ulcerative disease affects only about 1 in every 2 million people in European countries (including the UK), but is entirely more unpleasant than Chlamydia. While Chlamydia often has no symptoms, Chancroid produces painful open sores in the genital area and can make it extremely painful urinate.

Again though, while Chancroid may be significantly more noticeable than Chlamydia, luckily it’s treatable. A single dose of Azithromycin (1g) is about 89% effective at clearing up this bacterial infection and will usually improve symptoms in 3-7 days (although large ulcers may take 2 weeks to heal fully).

While Azithromycin might primarily be associated with its effectiveness in treating sexually transmitted infections, this is not its only use. Because it’s an antibiotic, it can also be used to treat a variety of bacterial infections including ones of the skin or ears.

When should I not take Azithromycin?

Although antibiotics are an extremely useful and effective treatment for a variety of ailments, their misuse and abuse is leading to antibiotic resistance. Basically, antibiotics work by seeking out bacteria and killing them, while leaving your human cells perfectly healthy. Drilling down a little, macrolide antibiotics (such as Azithromycin) block the bacteria’s protein-building function. Without the ability to do this, the bacteria cell essentially starves and cannot survive.

However, using antibiotics regularly gives certain bacteria a chance to recognise antibiotics and evolve to resist them. This is why it’s not only important to only take antibiotics when you really need them, but also why it’s important to try and avoid sexually transmitted bacterial infections, such as Chlamydia.

And while Azithromycin and other antibiotics might be highly effective at treating bacterial infections, they should never be taken as a treatment for viral infections like a cold, the flu or herpes (oral or genital). Not only will Azithromycin not work in treating these conditions, but taking it unnecessarily will contribute to the aforementioned antibiotic resistance problem.