# Co-trimoxazole (Sulfamethoxazole/Trimethoprim) in Nigeria

Co-trimoxazole (Sulfamethoxazole/Trimethoprim) has 35 active NAFDAC registrations in our October 2026 copy of the register, from 26 registration holders; 40 further listings have lapsed.

- Source: https://ogbogwu.com/drugs/co-trimoxazole/
- Drug class: Sulfonamide-diaminopyrimidine combination antibiotic (Antibiotics)
- Also known as: Septrin, Bactrim, SMX-TMP, Cotrimoxazole, Sulphamethoxazole-Trimethoprim, Caretrim
- Prescription required: yes
- On the WHO Model List of Essential Medicines
- Last updated: February 2026

## Price in Nigeria

As of October 2026, the only co-trimoxazole our sampled online pharmacies (HealthPlus) list is Primpex, at about ₦9,960. That is Primpex's price, not the molecule's: 33 co-trimoxazole brands are NAFDAC-registered and generic versions usually cost less, so ask a licensed pharmacy for a generic by name and check its NAFDAC number before you pay.

## What is Co-trimoxazole (Sulfamethoxazole/Trimethoprim)?

Co-trimoxazole, universally known in Nigeria as Septrin, is arguably the single most self-medicated drug in the country. Walk into any patent medicine store from Mushin to Maiduguri, from Aba to Abeokuta, and you will find Septrin prominently displayed. It is a combination antibiotic containing two active ingredients — sulfamethoxazole and trimethoprim — that work together to block two consecutive steps in the bacterial production of folic acid, a nutrient essential for bacterial growth and survival. By attacking bacteria at two different points in the same metabolic pathway, co-trimoxazole achieves a synergistic bactericidal effect that is more potent than either component alone.

In Nigeria, Septrin has achieved a cultural status that goes far beyond its clinical indications. Many Nigerians regard it as a cure-all, self-prescribing it for everything from headaches to malaria to sexually transmitted infections — most of which it is not effective against. This indiscriminate use has contributed significantly to the growing problem of antibiotic resistance in Nigeria. The original Septrin brand by GlaxoSmithKline (GSK) set the standard, but numerous locally manufactured generics including Emtrim (Emzor) and other brands are widely available at lower prices. All legitimate co-trimoxazole products must carry a NAFDAC registration number.

Despite the problem of misuse, co-trimoxazole remains a genuinely important antibiotic with specific, valuable roles. It is a WHO Essential Medicine and plays a critical role in the prevention of opportunistic infections in HIV-positive patients — Nigeria has one of the largest HIV-positive populations in the world, and co-trimoxazole preventive therapy (CPT) is a cornerstone of HIV care. It is also effective for urinary tract infections, certain respiratory infections, and some types of diarrhoea when used appropriately. The key message for Nigerians is clear: Septrin is a real antibiotic with real side effects and real resistance consequences — it should only be taken when properly indicated, not as a first response to every illness.

## What is Co-trimoxazole (Sulfamethoxazole/Trimethoprim) used for?

- Urinary tract infections (UTIs) — one of the most appropriate uses of co-trimoxazole, particularly for uncomplicated lower UTIs in women
- Acute otitis media (ear infections) in children — a common reason for co-trimoxazole prescription in Nigerian paediatric clinics
- Prophylaxis against opportunistic infections in HIV-positive patients (co-trimoxazole preventive therapy or CPT) — a lifesaving intervention in Nigeria's HIV programme
- Pneumocystis jirovecii pneumonia (PCP) prevention and treatment — an important opportunistic infection in people with advanced HIV/AIDS
- Acute exacerbations of chronic bronchitis in adults
- Traveller's diarrhoea caused by susceptible bacteria
- Toxoplasmosis prophylaxis and treatment in immunocompromised patients
- Nocardia infections and certain other specific bacterial infections as directed by a doctor

## Dosage

Always follow a doctor's or pharmacist's instructions; this is general reference information.

- Adults: The standard adult dose is 960mg (two 480mg tablets, or one double-strength 960mg tablet) taken twice daily for 5 to 7 days for most infections. For urinary tract infections, 960mg twice daily for 3 to 5 days is often sufficient. For HIV prophylaxis (CPT), the standard dose is 960mg once daily, taken every day indefinitely or until immune recovery on antiretroviral therapy as determined by the doctor. Take with a full glass of water and ensure adequate fluid intake throughout the course to prevent crystal formation in the kidneys.
- Children: Dosing in children is based on the trimethoprim component: 4mg TMP per kilogram per dose, given twice daily. For children aged 6 months to 5 years: 240mg (5ml of suspension or half a 480mg tablet) twice daily. For children aged 6 to 12 years: 480mg (10ml suspension or one 480mg tablet) twice daily. Co-trimoxazole suspension (240mg/5ml) is the preferred formulation for young children. Always use the measuring device provided. Co-trimoxazole should NOT be given to infants under 6 weeks of age.
- Elderly: Elderly patients may require dose adjustment due to reduced kidney function. A lower dose or longer interval between doses may be necessary. Elderly patients are also at increased risk of serious side effects including severe skin reactions and blood disorders. Regular monitoring of blood counts and kidney function is advisable.

Drink plenty of water while taking co-trimoxazole — at least 6 to 8 glasses per day — to help prevent the drug crystallising in the kidneys. Do not take co-trimoxazole if you are allergic to sulfonamides or trimethoprim. Complete the full course of treatment even if you feel better after a day or two. For HIV prophylaxis, do not stop taking the daily dose without your doctor's instruction. Avoid prolonged sun exposure while on co-trimoxazole as it can cause photosensitivity.

## Side effects

Common: Nausea and vomiting — the most frequently reported side effect; Diarrhoea and abdominal discomfort; Loss of appetite; Skin rash — may be mild but can progress to a serious reaction; stop the drug if a rash appears; Headache.

Serious (seek medical help immediately): Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) — life-threatening skin reactions causing widespread blistering and peeling of the skin. More common in patients with HIV. If you develop a rash with blistering, mouth sores, or fever, stop co-trimoxazole immediately and seek emergency care; Blood disorders — including anaemia, low white blood cell count (agranulocytosis), and low platelet count (thrombocytopenia), which can cause unusual bleeding, bruising, or increased susceptibility to infections; Severe allergic reaction (anaphylaxis) — difficulty breathing, swelling of the face or throat, and widespread rash; Liver damage (hepatitis) — yellowing of the skin or eyes, dark urine, severe fatigue; Kidney damage — crystal formation in the kidneys (crystalluria), particularly when fluid intake is inadequate; Hyperkalaemia (dangerously high potassium levels) — particularly in elderly patients or those with kidney problems.

When to see a doctor: Stop taking co-trimoxazole immediately and seek emergency medical attention if you develop a skin rash — even a mild one — as it can rapidly progress to a life-threatening reaction. Seek urgent care if you develop mouth sores, blistering skin, fever with rash, yellowing of the skin or eyes, unusual bruising or bleeding, sore throat with fever, or significantly reduced urine output. In Nigeria, where many people self-medicate with Septrin, it is particularly important to be aware of these warning signs. If you are HIV-positive and develop a rash on co-trimoxazole prophylaxis, do not simply continue — see your doctor, as desensitisation protocols may be needed.

## Warnings

Do not take if: Known allergy to sulfonamide drugs or trimethoprim — this is an absolute contraindication. Many Nigerians with sulfa allergies are unaware of the risk; Severe liver disease or jaundice; Severe kidney impairment (creatinine clearance below 15ml/min) without dialysis support; Infants under 6 weeks of age; Megaloblastic anaemia due to folate deficiency — co-trimoxazole further depletes folate; Porphyria; Pregnancy in the first trimester and near term (see pregnancy section).

Interactions: Warfarin — co-trimoxazole significantly increases the anticoagulant effect of warfarin, risking dangerous bleeding; INR must be closely monitored; Methotrexate — co-trimoxazole increases methotrexate toxicity by displacing it from protein binding and reducing its clearance; this combination should be avoided; Phenytoin — co-trimoxazole increases phenytoin blood levels, risking toxicity; ACE inhibitors and ARBs (lisinopril, losartan) — combined with co-trimoxazole, the risk of dangerously high potassium levels increases significantly, especially in elderly patients; Oral hypoglycaemics (glibenclamide, glipizide) — co-trimoxazole can increase their blood sugar-lowering effect, causing hypoglycaemia; Dapsone — increased risk of both drugs' side effects; Lamivudine — co-trimoxazole can increase lamivudine levels; relevant for HIV patients on both drugs in Nigeria.

Pregnancy & breastfeeding: Co-trimoxazole should be avoided during pregnancy, particularly in the first trimester (risk of neural tube defects due to folate antagonism) and near term (risk of neonatal jaundice and kernicterus). However, for HIV-positive pregnant women already on co-trimoxazole preventive therapy, WHO guidelines recommend continuing CPT throughout pregnancy because the benefits of preventing opportunistic infections outweigh the risks — this should be done under close medical supervision with concurrent folic acid supplementation. Co-trimoxazole passes into breast milk in small amounts but is generally considered compatible with breastfeeding at standard prophylactic doses. The drug should not be given to breastfeeding mothers of premature infants or babies with jaundice or G6PD deficiency.

## Brands in Nigeria

Well-known NAFDAC-registered brands: Septrin (GlaxoSmithKline (GSK), made in UK); Bactrim (Roche, made in Switzerland); Emtrim (Emzor, made in Nigeria); Tutrim (Tuyil Pharmaceutical, made in Nigeria); Caretrim (Dizpharm Nigeria Limited, made in Nigeria).
Full searchable brand list: https://ogbogwu.com/drugs/co-trimoxazole/brands/

## How to verify it is genuine

1. Check for a valid NAFDAC registration number on the packaging — given the widespread availability of co-trimoxazole in Nigeria, the risk of counterfeit products is significant
2. Use the NAFDAC Mobile Authentication Service (MAS): scratch the verification panel and send the code to 38353, or use the NAFDAC Green Book portal at greenbook.nafdac.gov.ng
3. Purchase from licensed pharmacies and registered patent medicine stores — avoid buying Septrin from roadside vendors, bus stops, or unregistered market stalls
4. Check the packaging for clear manufacturer details, batch number, manufacturing date, and expiry date. For GSK Septrin, verify the distinctive blister pack design and print quality
5. Genuine co-trimoxazole tablets should be smooth, uniformly coloured, and of consistent size. Reject any tablets that appear crumbly, discoloured, or have an unusual smell
6. Be cautious of unusually cheap Septrin — if a strip of adult-strength tablets costs far below what other pharmacies charge, the product may be substandard or counterfeit

Verify any NAFDAC number free (no login): https://ogbogwu.com/nafdac-checker/

## FAQs

### Can Septrin cure typhoid?

Many Nigerians use Septrin (co-trimoxazole) for typhoid, but it is no longer a reliable treatment. Resistance to co-trimoxazole among Salmonella typhi — the bacteria that causes typhoid — has risen dramatically in Nigeria and across sub-Saharan Africa. Studies show that 50-80% of Salmonella typhi isolates in Nigeria are now resistant to co-trimoxazole. This means that in many cases, taking Septrin for typhoid will not work and will only delay effective treatment while the infection worsens. Current recommended antibiotics for typhoid include ciprofloxacin, azithromycin, and ceftriaxone. If you suspect typhoid fever (persistent high fever, headache, abdominal pain), see a doctor for proper diagnosis and appropriate antibiotic treatment rather than self-medicating with Septrin.

### Why do HIV patients take Septrin every day?

HIV-positive patients in Nigeria are often placed on daily co-trimoxazole (960mg once daily) as preventive therapy, commonly called CPT (co-trimoxazole preventive therapy). This is because HIV weakens the immune system, leaving patients vulnerable to opportunistic infections like Pneumocystis pneumonia, toxoplasmosis, certain diarrhoeal diseases, and malaria. Daily co-trimoxazole has been shown to dramatically reduce illness and death from these infections, even in patients who are also taking antiretroviral therapy (ARVs). The WHO and Nigerian national HIV guidelines recommend CPT for all HIV-positive adults and children, particularly those with low CD4 counts. CPT is one of the most cost-effective interventions in HIV care — it costs very little and saves many lives. Patients should continue CPT until their doctor determines that their immune system has recovered sufficiently on ARV treatment.

### Is it safe to give Septrin to children?

Co-trimoxazole can be given to children aged 6 weeks and older, and it remains an important paediatric antibiotic in Nigeria, particularly for ear infections and urinary tract infections. The suspension formulation (240mg/5ml) is specifically designed for children and allows accurate dosing by weight. However, many Nigerian parents give Septrin to children for any fever or illness without a proper diagnosis — this is dangerous. Septrin will not treat malaria, viral infections, or most childhood fevers, and unnecessary use exposes children to the risk of serious side effects (including severe skin reactions) and promotes antibiotic resistance. Children should only receive Septrin when prescribed by a healthcare professional for a confirmed or strongly suspected bacterial infection. If your child develops a rash while taking Septrin, stop it immediately and seek medical attention.

### Why is taking Septrin for every illness dangerous?

Septrin (co-trimoxazole) is Nigeria's most self-medicated antibiotic, and this widespread misuse is causing serious harm in two ways. First, co-trimoxazole has potentially serious side effects — including life-threatening skin reactions (Stevens-Johnson syndrome), blood disorders, and kidney damage — that are not justified when the drug is taken for conditions it cannot treat, such as malaria, viral fevers, or headaches. Second, every unnecessary use of Septrin helps bacteria develop resistance to it, meaning it will no longer work when it is truly needed. Nigeria already has very high rates of co-trimoxazole resistance among common bacteria. If this continues, we risk losing an antibiotic that is vital for protecting HIV patients, treating UTIs, and managing childhood infections. The responsible approach is to take Septrin only when a qualified healthcare professional has determined it is the right treatment for your specific condition.

## Sources

- NAFDAC Greenbook (official register of approved products in Nigeria)
- WHO Model List of Essential Medicines
- British National Formulary (BNF)
- Nigerian Standard Treatment Guidelines (Federal Ministry of Health)