Novatrim is co-trimoxazole — trimethoprim with sulfamethoxazole — as tablets and a paediatric suspension. It is given daily to prevent PCP pneumonia in people with HIV, including HIV-exposed babies from six weeks of age, and it also treats urinary, chest, ear and skin infections.
What is Novatrim?
Novatrim contains two antibiotics working together:
- Tablet: trimethoprim 80 mg + sulfamethoxazole 400 mg
- Suspension: trimethoprim 40 mg + sulphamethoxazole 200 mg per 5 ml
That combination is called co-trimoxazole. It is a Schedule 4 prescription medicine, also sold as Purbac, Troxazole, Doctrim and Bactrim.
The two ingredients block consecutive steps in the same pathway. Bacteria must manufacture their own folate to build DNA — humans absorb folate from food instead, so the pathway exists in the bacterium and not in us. Sulfamethoxazole blocks one enzyme in that chain, and trimethoprim blocks the next. Interrupting a pathway at two consecutive points is far more effective than blocking either step alone, and makes resistance considerably harder to develop.
Its most important role in South Africa is preventive. Co-trimoxazole taken daily protects people with weakened immunity against Pneumocystis jirovecii pneumonia (PCP) and several other opportunistic infections — and it demonstrably reduces deaths. That is why it appears here among preventive treatments rather than only as an antibiotic.
What is Novatrim commonly used for?
Preventing infection (prophylaxis):
- In adults and children living with HIV, where the CD4 count is low, continued until the immune system recovers on antiretroviral treatment such as tenofovir-based therapy.
- In HIV-exposed infants, typically started at six weeks of age and continued until HIV infection has been excluded and breastfeeding has ended. This is standard South African practice.
- In other immunosuppressed people, including some transplant recipients and those on immune-suppressing treatment.
- Preventing recurrent urinary tract infections, in selected cases.
Treating infection:
- Urinary tract infections.
- Chest infections, including PCP itself at much higher amounts.
- Middle ear infections in children.
- Skin and soft tissue infections.
- Some gut infections, including shigellosis.
About giving it to a baby
Parents frequently ask why a well baby is on a daily antibiotic. The answer is that an HIV-exposed infant is protected before anyone knows whether they are infected. PCP pneumonia in an infant develops fast and is often fatal, and by the time it is apparent it may be too late. Starting at six weeks protects the baby through the window when their status is still being confirmed.
The baby is not being treated for an illness — they are being kept from developing one. Feeling well is exactly the intended result, and it is not a reason to stop. It is continued until a doctor confirms it can be stopped, which depends on HIV testing and on when breastfeeding ends.
How Novatrim fits into this medicine category
| Group | Examples | Role |
|---|---|---|
| Co-trimoxazole prophylaxis | Novatrim, Purbac | Prevents PCP and other opportunistic infections |
| Antiretrovirals | Lamivudine, tenofovir | Treats HIV; restores immunity |
| TB preventive therapy | Isoniazid (Winthrop Isoniazid) | Prevents active tuberculosis |
| Treatment antibiotics | Amoxicillin, azithromycin | Treat an infection that is present |
Co-trimoxazole prophylaxis and antiretroviral therapy work together: the antiretrovirals rebuild immunity over months, and co-trimoxazole covers the gap. See the vaccines and prevention hub.
What to check before using Novatrim
Say so if you have a sulfa allergy — before the first dose. Sulfonamide allergy is relatively common, reactions can be severe, and this is the single most important check.
For the suspension: shake the bottle well and use the syringe or measure supplied, not a kitchen spoon. Paediatric amounts are calculated by weight and change as a baby grows, so the dose is reviewed at clinic visits.
Do not stop a preventive course because the person feels well, and do not run out — collect repeats before the supply ends.
Drink plenty of water while taking it.
Tell your prescriber or pharmacist if:
- You have kidney or liver disease.
- You have G6PD deficiency, where sulfonamides can break down red blood cells.
- You have folate deficiency, or take methotrexate.
- You are pregnant, planning pregnancy or breastfeeding. It is generally avoided in the first trimester and near term.
- You take warfarin — co-trimoxazole markedly increases bleeding risk; phenytoin; an ACE inhibitor, ARB or spironolactone, where potassium can rise dangerously; or a diabetes tablet, where blood sugar can drop.
- The medicine is for an infant under 6 weeks, where it is not normally used.
Follow the dispensing label. This page does not set doses, and the amount for prevention differs greatly from the amount for treatment.
Possible cautions and when to ask a pharmacist or doctor
Take any rash seriously. Co-trimoxazole causes rash more often than most antibiotics. Most are mild, but it is also associated with the rare and very serious Stevens-Johnson syndrome and toxic epidermal necrolysis. Stop and seek medical help immediately for a rash that blisters or peels, sores in the mouth, eyes or genitals, or a widespread rash with fever. Do not wait to see whether it settles, and this applies to children as much as adults.
Potassium can rise, particularly in older adults, with reduced kidney function, or alongside ACE inhibitors, ARBs or spironolactone.
Blood counts can be affected with prolonged use. Report unusual bruising or bleeding, a sore throat, mouth ulcers or persistent fever.
Sun sensitivity is common — use sunscreen and cover up.
Nausea and reduced appetite are frequent; taking it with food helps.
In a baby, report poor feeding, unusual sleepiness, a rash, jaundice, or vomiting after doses.
Seek urgent medical attention for a blistering or peeling rash, mouth or eye sores, swelling of the face or throat, difficulty breathing, unexplained bruising or bleeding, persistent high fever, severe or bloody diarrhoea, marked muscle weakness, yellowing of the skin or eyes, or a significant reduction in urine. In an infant, seek help for breathlessness, fast breathing, poor feeding or unusual drowsiness.
Related medicine guides
Frequently asked questions
What is Novatrim used for? Preventing PCP pneumonia and other infections in people with weakened immunity, and treating urinary, chest, ear and skin infections. It contains co-trimoxazole.
What is Novatrim suspension used for in babies? It is given daily to HIV-exposed infants, usually from six weeks, to prevent PCP pneumonia while their HIV status is being confirmed. The baby is not ill — it is protection.
Why is my baby on an antibiotic if they are not sick? That is the point of prophylaxis. PCP develops rapidly in infants and is often fatal. The medicine prevents it during the window when status is still uncertain.
When can it be stopped? Only when a doctor says so. That depends on HIV testing results and on when breastfeeding ends.
Is it the same as Purbac or Bactrim? Yes. All are brands of co-trimoxazole.
My child has a rash. Should I keep giving it? Contact the clinic. Stop and seek help immediately if the rash blisters or peels, involves the mouth or eyes, or comes with a fever.