Antibiotics: why finishing the course still matters
Antibiotics do nothing for a cold, and South Africa already has infections that are difficult to treat — how you use them matters to everyone.
They do not work on viruses
Antibiotics kill bacteria. Colds, flu, most sore throats, most coughs and most cases of sinus congestion are caused by viruses, and an antibiotic does nothing at all for them — it will not shorten the illness or stop it becoming worse.
What it will do is expose the bacteria you carry normally to the medicine, giving resistant ones an advantage, and expose you to side effects for no benefit. Green mucus, incidentally, is not evidence of bacterial infection — it is a normal stage of many viral illnesses.
What resistance actually means here
When bacteria are repeatedly exposed to antibiotics, the ones that survive multiply. Over time, common infections stop responding to the medicines that used to clear them easily, and treatment moves to alternatives that are harder to give, more toxic, or only available in hospital.
South Africa already deals with this at scale, most visibly with drug-resistant TB, which takes far longer to treat and has worse outcomes than ordinary TB. It is not a distant or theoretical problem.
Using them properly
- Take the full course exactly as prescribed, even after you feel better — feeling better usually comes before the infection is cleared.
- Take doses evenly spaced, and follow any food instructions. Some are absorbed poorly with dairy or with antacids.
- Never use antibiotics left over from a previous illness, and never take someone else's.
- Do not pressure a clinician for antibiotics. Being told you do not need them is usually good news.
- Report a rash, swelling, breathing difficulty or severe diarrhoea rather than pushing on.
- Tell the prescriber about any previous antibiotic allergy, and about other medicines you take.
When antibiotics genuinely are needed
None of this means avoiding antibiotics. Bacterial pneumonia, a kidney infection, bacterial meningitis, an infected wound and many sexually transmitted infections all need prompt treatment, and delay causes real harm.
Antibiotics commonly used in South African primary care:
Amoxicillin — Amoxil, Betamox, Moxypen, Ospamox
Upper and lower respiratory tract infections; UTIs; skin infections; otitis media; H. pylori eradication
Amoxicillin-Clavulanate (Co-amoxiclav) — Augmentin, Adco-Amoclav, Curam, Clavulin
Complicated skin infections; sinusitis; lower respiratory infections; UTIs with resistant organisms
Doxycycline — Doximal, Cyclidox, Adco-Doxycycline, Vibramycin
STIs (chlamydia, syphilis); atypical pneumonia; malaria prophylaxis; tick bite fever; acne (low dose)
Metronidazole — Flagyl, Adco-Metronidazole, Metrosa, Medazol
Anaerobic infections; Trichomonas; bacterial vaginosis; Giardia; amoebic dysentery; C. diff
The goal is the right antibiotic, for the right infection, for the right length of time — not fewer antibiotics at any cost.
Common questions
- Can I stop the antibiotic once I feel better?
- Take the course you were prescribed. If you are having side effects that make you want to stop, contact the prescriber — there is usually an alternative, and stopping without telling anyone is the worst of the options.
- Can I drink alcohol on antibiotics?
- With most, moderate alcohol does not interact directly, though it will not help you recover. With metronidazole it causes a genuinely unpleasant reaction and must be avoided during the course and for a period afterwards. Check with the pharmacist for the one you have been given.
Sources
- Standard Treatment Guidelines and Essential Medicines ListNational Department of Health, South Africa
- Antimicrobial resistance surveillance and stewardship guidanceNational Institute for Communicable Diseases (NICD)
Last reviewed 4 August 2026.