Antibiotics

These medicines are not alternatives to one another. What separates them is the type of organism they act against and therefore the situations in which a prescriber would consider them. There is no dose column here by design.

Swipe the table sideways to see every column.

Course profiles above describe the general shape of treatment, not a schedule. What you take, and for how long, is set by the prescriber who diagnosed the infection. Complete the course they specify even if you feel better partway through.

1. 1Get the diagnosis before the medicine

   The single most useful thing you can do is find out what is actually causing the illness. A prescriber may take a swab, a urine sample or a blood test. Choosing an antibiotic without that is guesswork, and guessing wrong means side effects with no benefit and a contribution to resistance.

2. 2Declare every allergy

   Penicillin allergy rules out amoxicillin; sulfonamide allergy rules out co-trimoxazole. Be specific about what happened previously — a rash, swelling, breathing difficulty — because the distinction changes what a prescriber can safely use.

3. 3Bring your full medicine list

   Co-trimoxazole interacts with warfarin, methotrexate and some diabetes and blood-pressure medicines. Antibacterials can affect other treatments in ways that matter. Include over-the-counter products, supplements and anything herbal.

4. 4Plan to finish the course

   Antibiotic courses are set as a whole. Stopping when symptoms improve leaves the least susceptible bacteria behind. If side effects make finishing difficult, contact your prescriber rather than simply stopping — there is usually an alternative.

There is no consumer-level way to choose between these medicines, and any page that offers one is misleading you. The right antibacterial depends on the site of infection, the likely organism, local resistance patterns, your allergies, your kidney function and what else you take. The right antiparasitic depends on the parasite. Use what your prescriber has identified for your specific situation, complete the course, and go back to them if it is not settling.

• Bacterial infections of the chest, ear, nose, throat and sinuses where a prescriber has identified a bacterial cause — amoxicillin
• Urinary tract infections — amoxicillin or co-trimoxazole, depending on the organism and local resistance patterns
• Skin and soft-tissue bacterial infections
• Dental infections and abscesses, alongside dental treatment of the cause
• Some specific infections where co-trimoxazole is the established choice, including certain chest infections in people with weakened immunity
• Helicobacter pylori eradication, where amoxicillin is used as part of a combination regimen decided by a prescriber
• Particular parasitic worm infections — ivermectin
• Scabies and rosacea-associated skin conditions caused by mites — topical ivermectin
• Malaria prophylaxis and treatment in defined situations, and certain autoimmune conditions including rheumatoid arthritis and lupus — hydroxychloroquine, under specialist supervision
• Parasite treatment in animals — fenbendazole, veterinary use only

• Antibiotics work only against bacteria. They have no effect on colds, influenza, COVID-19 or most sore throats, and taking them for a viral illness gives you the side effects without any benefit while contributing to resistance.
• Finish the full course exactly as prescribed, even once you feel better. Stopping early selects for the bacteria that were hardest to eliminate.
• Never share antibiotics, never take leftovers from a previous illness, and never take someone else's prescription. Return unused medicine to a pharmacy for safe disposal.
• Tell your prescriber about any allergy before amoxicillin or co-trimoxazole is considered — penicillin allergy for the former, sulfonamide allergy for the latter. A previous reaction to one penicillin generally means avoiding the whole group.
• Seek urgent medical care for signs of a severe allergic reaction: swelling of the face, lips or throat, difficulty breathing, a widespread rash with blistering or peeling skin, or feeling faint. In an emergency in Australia, call 000.
• Contact your prescriber promptly for severe or persistent diarrhoea during or after a course of antibiotics, which can signal a serious bowel infection, and for unusual bruising, sore throat with fever, yellowing of the skin or eyes, or a dramatic reduction in urine output.
• Co-trimoxazole interacts with warfarin, methotrexate, some diabetes medicines and medicines that raise potassium. It also increases sensitivity to sunlight — relevant in Australia, so use sun protection.
• Antibiotics can reduce the reliability of other treatments and can upset the normal balance of bacteria in the gut and elsewhere. Mention anything unexpected to your pharmacist.
• Hydroxychloroquine used long term needs monitoring arranged by the prescribing specialist, including eye examinations. Do not start, stop or alter it on your own initiative.
• Fenbendazole is a veterinary product for animals only. It is not an approved human medicine and has not been assessed for human safety by the TGA.
• Always read the patient information leaflet, and check packaging, batch number and expiry before use.

• Confirm the prescription position

  Amoxicillin, co-trimoxazole, ivermectin and hydroxychloroquine are Schedule 4 Prescription Only Medicines in Australia. Antibiotics in particular are prescription-controlled for a public health reason, not a commercial one — uncontrolled supply is one of the main drivers of resistance.

• Check ARTG status and origin

  Products the TGA has assessed for Australian supply appear on the Australian Register of Therapeutic Goods. Generics made for other markets may be produced under Good Manufacturing Practice standards without ARTG registration. Know which you are ordering and mention it to your pharmacist.

• Inspect the packaging

  Look for intact manufacturer packaging, a legible batch number and expiry date, unbroken blister foil and an included leaflet. Antibiotic capsules should be uniform in colour and size. Anything loose, damaged, unlabelled or short-dated is a reason to stop.

• Match the product to the prescription

  Check the active ingredient and labelled strength on the pack against what your prescriber specified. Brand names vary widely between markets while the active ingredient stays the same — the ingredient is the thing to verify.

• Assess the seller

  A verifiable address, a working contact route, Australian dollar pricing, a stated dispatch and delivery timeframe, and a published returns and complaints process. Storage handling matters for antibacterials, so a seller who says nothing about how stock is stored is telling you something.

• Never stockpile

  Buying antibiotics 'to have on hand' is the behaviour public health advice most consistently warns against. It leads to self-diagnosis, wrong-medicine use, part-courses and expired stock — every failure mode that drives resistance.

• Orders are dispatched within one business day of payment clearing, with a confirmation email and tracking where available.
• Standard delivery is 2–4 business days Australia-wide, free on orders over $150. Regional and remote destinations can take longer.
• Plain, unbranded outer packaging on every parcel — nothing outside identifies the contents.
• Nothing in this range requires cold-chain shipping in the presentations we supply. Store tablets and capsules below 25°C, in the original packaging, away from heat, direct sunlight and humidity.
• Topical ivermectin cream should be kept tightly closed at room temperature and not frozen. Do not use it after the expiry date, or after the period-after-opening the leaflet specifies.
• Keep every antibacterial well out of reach of children, and never transfer it into an unlabelled container — the batch, ingredient and expiry need to stay readable for the whole course.
• Take unused or expired antibiotics to a pharmacy for disposal rather than putting them in the bin or down the sink. Australian pharmacies participate in a medicine return scheme for exactly this purpose.

Antibacterial vs antiparasitic

Antibacterials act against bacteria; antiparasitics act against parasites such as worms and mites. They target different organisms and are not substitutes for one another.

Broad-spectrum

An antibiotic active against a wide range of bacterial types. Useful when the exact organism is unknown, but broad-spectrum use also disturbs more of the body's normal bacteria and puts more selective pressure behind resistance.

Antimicrobial resistance

The process by which bacteria become able to survive the medicines that once eliminated them. Driven by unnecessary use, incorrect choice and incomplete courses. It is why prescribing is controlled.

Antimicrobial stewardship

The organised effort within Australian health services to make sure antibiotics are used only where needed and in the right way, coordinated nationally by the Australian Commission on Safety and Quality in Health Care.

Culture and sensitivity

A laboratory test that grows the bacteria from a sample and checks which antibiotics act against it. It is what turns an educated guess into a targeted choice.

Course

The complete run of treatment a prescriber specifies. Antibiotic courses are designed as a whole; stopping partway is not the same as taking a shorter course.

Penicillin allergy

A genuine immune reaction to penicillin-class antibiotics, which includes amoxicillin. Worth having formally assessed, because many people carry the label from a childhood rash that was never confirmed.

Schedule 4 (Prescription Only Medicine)

The Australian classification meaning a medicine can only be supplied against a prescription from an authorised practitioner. Amoxicillin, co-trimoxazole, ivermectin and hydroxychloroquine all sit here.

Or read the reference page for an individual active ingredient:

For independent, Australian information about the medicines in this range, we point customers to the following bodies. Search for the medicine by name on their sites rather than relying on overseas material.

• Therapeutic Goods Administration (TGA)
• Australian Register of Therapeutic Goods (ARTG)
• Healthdirect Australia
• Australian Commission on Safety and Quality in Health Care
• Pharmaceutical Benefits Scheme (PBS)