Key takeaways

  • Antibiotics do not speed recovery from viral flu or colds. HealthHub also explains that green phlegm can occur with viral or bacterial infection; colour alone does not establish a need for antibiotics. HealthHub
  • Broader coverage needs a clinical reason. KKH’s stewardship team reviews selected antibiotics, particularly carbapenems, to reserve broad-spectrum treatment for conditions that need it. KKH
  • Follow the current prescription and ask before changing it. Do not stop, extend, share, save or reuse antibiotics independently. HealthHub lists hospital and pharmacy counters where leftovers can be returned for disposal. HealthHub

Antibiotics for cough, flu or sore throat: diagnosis comes first

Antibiotics for Cough, Flu or Sore Throat: Diagnosis Comes First

Green phlegm can come from the white blood cells produced during an infection. HealthHub explains that this happens with viruses as well as bacteria. The colour cannot tell you whether you need an antibiotic.

Its examples of bacterial infections include strep throat, whooping cough and tuberculosis. Flu and the common cold appear on the viral list. With a cough or sore throat, the prescriber first has to work out what is causing it. Where the infection is, how severe it is, allergies, recent antibiotic use and local resistance all affect the prescription.

Why do the same symptoms have different treatments?

The symptoms do not identify the organism or establish that an antibiotic can help. Cough, fever, throat pain, nasal symptoms and tiredness describe the body’s response. Influenza and the common cold are viral. Some sore throats are bacterial, including streptococcal infection, but many are not. A cough may also come from asthma, reflux, allergy, medication effects or a lower-respiratory condition rather than an infection that antibiotics can treat.

HealthHub’s Singapore antibiotic-responsibility programme states plainly that antibiotics do not work on viruses. Using one for a viral illness does not make recovery faster and still exposes the user to adverse effects and selection pressure for resistant bacteria.

A clinician may use the symptom pattern, examination, outbreak context and sometimes testing to decide whether bacterial infection is likely. HealthHub’s FAQ says blood or urine tests or an X-ray may sometimes be needed. Ask what diagnosis is being treated and what finding supports an antibiotic.

In the Singapore population survey, 706 people answered an online questionnaire in May and June 2019. Only 35.6% correctly answered both questions on antibiotic effectiveness against bacteria and viruses. Another 35.4% believed antibiotics could speed recovery from common respiratory illnesses. The sample over-represented university-educated respondents, so these figures describe that survey, not a current national estimate.

Why are amoxicillin, azithromycin, doxycycline and levofloxacin not a strength ladder?

They are a penicillin, a macrolide, a tetracycline and a fluoroquinolone, respectively. Amoxicillin, azithromycin, doxycycline and levofloxacin cannot be ranked by a single measure of strength. They differ in bacterial coverage, resistance patterns, tissue penetration, interactions, adverse effects and the infections for which guidelines use them.

In KKH’s account of its stewardship programme, pharmacist Dr Seah Xue Fen describes daily reviews of selected prescriptions, particularly carbapenems. Her article is dated 16 November 2022. Infectious-disease physicians and stewardship pharmacists carry out the reviews for babies, children and women with obstetric or gynaecological conditions. They recommend reserving broad-spectrum antibiotics for conditions that need them.

Broader coverage also disturbs normal bacteria and adds resistance pressure when it is unnecessary. For a particular infection, the organism and site may make a narrower antibiotic suitable.

You can look up ingredient names in the antibiotics catalogue. Keep the pack with you when asking about a prescription: its ingredient, strength, form and directions identify what you have. Even if you recognise the brand from a previous illness, the cause of this cough still needs assessment.

What should you ask when an antibiotic is prescribed?

Ask what infection is suspected and whether tests are needed. The 2019 survey found that only 28.3% of respondents who reported an antibiotic prescription recalled an explanation of possible side effects; 18.1% recalled a discussion of resistance. Ask about both, along with missed doses and the directions on your prescription.

Tell the prescriber if an earlier antibiotic caused an allergy or severe diarrhoea. Bring your medicine list and mention pregnancy or any kidney or liver problems.

Nausea, vomiting, diarrhoea, bloating and loss of appetite appear in HealthHub’s list of common antibiotic side effects. If these become worrying, or you develop other symptoms such as an allergic rash, its advice is to consult a doctor immediately. The clinician may change treatment because of an adverse effect, a test result or a revised diagnosis. Otherwise, keep to the schedule and duration prescribed. Do not decide for yourself to stop, extend or repeat it; ask the clinician or pharmacist managing the prescription.

For leftovers, HealthHub names restructured and private hospitals and Guardian, Unity and Watsons outlets with pharmacist counters. Return unused antibiotics for disposal; do not save them for another illness or give them to someone else. Matching an overseas pack by its colours is unreliable, too. You could end up with the wrong ingredient, form, strength or duration, and a serious illness could go unassessed.

How does resistance change the comparison?

Resistant bacteria respond less well or no longer respond to antibiotics intended to kill or suppress them. KKH names methicillin-resistant Staphylococcus aureus and extended-spectrum beta-lactamase-producing Enterobacteriaceae among the resistant organisms spreading globally. Their infections can require longer hospital stays and can be fatal.

The 2019 survey asked about the mechanism. Of 706 respondents, 62.5% thought the body becomes resistant to antibiotics and 48.5% thought the medicines become less powerful. Resistance concerns changes in the bacteria, selected through unnecessary or incorrect antibiotic use and spread through poor infection control. Using a broader antibiotic without need can increase that pressure.

In CDA’s HealthHub diagram, animals and crops given antibiotics inappropriately carry resistant bacteria into meat and food crops. Bacteria can reach people through food or direct contact with animals, or through water, soil and air. The diagram also shows spread between patients where healthcare facilities are unclean and hygiene is poor.

Singapore calls its approach One Health because it includes people, animals, food and the environment. The CDA overview also names surgery, transplantation and chemotherapy among the treatments that depend on effective infection prevention and treatment.

Resistance patterns also mean that advice copied from another country or an old forum post may not fit. Guidelines, local data and the person’s recent cultures or antibiotic history can change the choice.

What changes the answer?

Diagnosis, severity, allergy history, age, pregnancy, organ function and recent treatment change the choice.

  • Likely diagnosis and infection site. Throat, sinus, lung and non-respiratory infections are not interchangeable labels.
  • Severity and red flags. Breathing difficulty, confusion, severe dehydration, blue or grey lips, chest pain or rapid deterioration require urgent assessment.
  • Allergy history. A side effect such as nausea is different from immediate swelling, breathing difficulty or a severe skin reaction.
  • Age, pregnancy and organ function. These can change medicine selection and monitoring.
  • Recent antibiotics and test results. Prior exposure, cultures and local resistance can alter the useful options.
  • Other medicines. Some antibiotics interact with anticoagulants, heart-rhythm medicines, antacids or supplements.

When is urgent help needed?

Get urgent help for breathing difficulty or swelling of the face or throat. Widespread blistering, severe weakness, confusion and being persistently unable to drink also need urgent help. If the illness gets worse, comes back after treatment or is not improving as expected, have it assessed again.

Take your remedies along to that review. Multi-symptom products can contain duplicate cold-and-flu ingredients, so include those as well as the antibiotic.

Do and don’t

Do:

  • Follow the current prescription and ask the managing clinician or pharmacist about concerns.
  • Return leftover antibiotics for disposal through the hospital or pharmacy counters listed by HealthHub.

Don’t:

  • Use green phlegm, a familiar brand or a previous prescription to diagnose a bacterial infection.
  • Share, save, extend or stop antibiotics without advice.

Sources