The dos and don’ts of taking antibiotics

Antibiotics can have a trying impact on our gut health. Photo / 123RF

From the importance of vaccines to laying off the booze, experts offer their tips on using the drugs.

We all think we’re familiar with the rules of antibiotic use. Take them only as prescribed, don’t stop halfway through, and maybe take a probiotic afterwards. But there’s another unexpected piece of advice that experts added to the list last week: avoid salad.

According to researchers at the University of Nottingham, bacteria carrying genes resistant to antibiotics are often found on salad vegetables. The scientists claimed that eating these foods could lead to these resistant genes being transferred to the gut, resulting in their resistance to future antibiotics and the creation of drug-resistant superbugs. “Those resistances could become established in your gut ecosystem,” said Dov Stekel, professor of computational biology, who led the study, suggesting that it would be wise to cook food thoroughly and avoid salad while taking antibiotics.

The wider scientific community is divided on these claims. But antibiotic resistance is well documented – and responsible for more than five million deaths globally each year. Health experts warn that this could climb to at least 10 million by 2050. It occurs naturally but is accelerated by the misuse and overuse of antibiotics. But there are things you can do to minimise the risk of antibiotic resistance. Here are the experts’ dos and don’ts…

Don’t: Expect antibiotics for a viral infection

Patients suffering common respiratory infections often pressure their GP to prescribe antibiotics for a viral infection. But research conducted in 2018 found that 20 per cent of antibiotic prescriptions are unnecessary.

Doctors are always trying to balance “curing an infection and minimising the risk of antibiotic resistance,” says Prof Willem van Schaik of the Institute of Microbiology and Infection. “If their use is necessary, then that is a good use; we wouldn’t want to say nobody [can use] antibiotics – but reducing their unnecessary use is a very good step.”

It can be difficult to identify whether an infection is bacterial or viral as some of the symptoms can be similar, but most cases of a cough, cold, the flu or a sore throat are viral and won’t respond to antibiotics. But how can you tell which is which?

As a patient, the best course of action is to flag concerning symptoms to your GP. “It’s an overgeneralisation, but generally viruses have a higher fever than bacteria,” says Dr Jeremy Harris from the Private GP Group.

Do: Take a probiotic or eat fermented foods along with your prescription

A course of antibiotics can have a negative impact on the gut: as well as killing bad bacteria, they can wipe out the “good” bacteria that make up the gut microbiome.

“When you take an antibiotic, you do so because it’s going to hit a particular microbe – if you have a chest infection, you want it to hit the microbe in your lung, explains Ted Dinan, a professor of psychiatry at University College Cork and co-author of The Psychobiotic Revolution. “The problem with antibiotics is they have “off-target” effects… A broad spectrum antibiotic is likely to knock out a lot of bacteria in your gut.” It takes around 12 weeks for the gut microbiome to return to normal or nearly-normal after a course of antibiotics.

Many suggest taking a probiotic to counter this effect. “A probiotic is traditionally defined as a bacteria that when we ingest it, it has a positive health benefit. “I don’t think the evidence is conclusive that taking a probiotic is particularly useful when you’re taking antibiotics,” says Dinan. “But I think there is enough evidence to suggest it is sensible. I would argue that the best matrix for ingesting probiotics is [through] foods, not capsules.”

Don’t: Take an old course of antibiotics for a later illness

For the same reason, van Schaik strongly advises against sharing or storing antibiotics. “You should only take a course of antibiotics when it has been prescribed to you,” he says. “You should never go back and self-medicate.”

Dr Harris agrees that you mustn’t do so “off your own back” as the drugs might not be the right antibiotics for a new condition – always seek medical advice.

Do: Stay up to date with vaccines

The key difference between bacteria and viruses is that bacteria are cells that can survive on their own and can be treated with antibiotics, and viruses cause infection by multiplying within a healthy host cell.

Vaccination is “very important,” in the fight against antibiotic resistance, says van Schaik. “There are multiple bacterial infections we are vaccinated against, including meningitis, for example, and by taking these vaccines you protect yourself against life-threatening disease.”

Don’t: Stop your course of pills halfway through

While there is research ongoing into the optimal number of days to take antibiotics for certain infections, the current advice to always take them as prescribed still applies, according to van Schair. Stopping halfway through a prescribed course can encourage antibiotic resistance.

Do: Limit your alcohol use

According to NHS guidance, moderate alcohol consumption is unlikely to cause problems when taking common antibiotics. “However, there are certain antibiotics that you will make you sick if you drink with them,” says Dr Harris. “As a general rule, everyone taking antibiotics should limit their alcohol intake. When you’re not well, the alcohol and the antibiotic will compete for how they’re metabolised, so you might get a worse response to the antibiotic,” he says. “It’s not that you can’t drink, it’s that you won’t get better quickly if you do drink.”