Package Leaflet: Information for the User
Septrin 80 mg/400 mg Tablets
(trimethoprim/sulfamethoxazole)
Read all of this leaflet carefully before you start taking this medicine because it contains important information for you.
Contents of the Package Leaflet
Septrin is an antibiotic that eliminates the bacteria that cause infections. It contains two different drugs called trimethoprim and sulfamethoxazole (a sulfonamide).
Antibiotics are used to treat bacterial infections and are not effective against viral infections such as the flu or the common cold.
It is essential that you follow the instructions regarding dosage, administration interval, and treatment duration as indicated by your doctor.
Do not store or reuse this medication. If you have any leftover antibiotic after completing treatment, return it to the pharmacy for proper disposal. Do not throw away medications down the drain or in the trash.
Septrin is indicated for the treatment of the following infections: treatment and prevention of pneumonia caused by Pneumocystis jiroveci (P. carinii), prevention of toxoplasmosis, nocardiosis, and melioidosis.
Septrin may also be useful for other infections: middle ear infections, lung infections in patients with chronic bronchitis, urinary tract infections (bladder, kidneys), infectious diarrhea, treatment of toxoplasmosis, genital and/or perianal lesions (granuloma inguinale or donovanosis), and brucellosis.
Do not take Septrin 80 mg/400 mg Tablets
Warnings and precautions
Consult your doctor or pharmacist before starting to take Septrin 80 mg/400 mg Tablets.
Rare cases of death have occurred due to severe reactions, including fulminant hepatic necrosis (severe liver damage), agranulocytosis (decrease in the number of a certain type of white blood cell), aplastic anemia (insufficiency of the bone marrow to produce different types of cells), other blood disorders, and hypersensitivity of the respiratory system.
Life-threatening skin rashes have been described with the use of Septrin, initially appearing as red or circular spots, often with a central blister.
Other additional signs that may appear are sores in the mouth, throat, nose, genitals, and conjunctivitis (swollen and red eyes).
These life-threatening skin rashes are often accompanied by flu-like symptoms. The rash can progress to the formation of generalized blisters or skin peeling.
The period of highest risk of severe skin reactions is during the first few weeks of treatment.
If you have developed Stevens-Johnson syndrome, toxic epidermal necrolysis, or acute febrile neutrophilic dermatosis with the use of Septrin, you should not use Septrin again at any time.
If you develop a rash or these skin symptoms, stop taking Septrin, go to a doctor immediately, and inform them that you are taking this medication.
If you experience a severe skin reaction: a red and scaly rash with bumps under the skin and blisters (generalized exanthematous pustulosis), contact a doctor as soon as possible and inform them that you are taking this medication.
Rare cases of hypersensitivity reactions with eosinophilia (increase in a certain type of white blood cell) and associated systemic symptoms have been reported with the use of Septrin.
As a consequence of colonization with Clostridium difficile, the use of Septrin may lead to the development of pseudomembranous colitis, which manifests as diarrhea.
If you experience an unexpected worsening of cough and shortness of breath, inform your doctor immediately.
Haemophagocytic lymphohistiocytosis
Very rare cases of excessive immune reactions due to unregulated activation of white blood cells, causing inflammation (haemophagocytic lymphohistiocytosis), which can be potentially fatal if not diagnosed and treated early, have been reported. If you experience multiple symptoms such as fever, swelling of the lymph nodes, feeling of weakness, dizziness, shortness of breath, bruising, or skin rash, either simultaneously or with a slight delay, contact your doctor immediately.
Taking Septrin 80 mg/400 mg Tablets with other medications
Tell your doctor or pharmacist if you are taking, have recently taken, or might take any other medications.
Septrin may enhance the effect and/or toxicity of some medications. It is essential that you inform your doctor if you are taking or have recently taken any of the following medications:
When trimethoprim is administered with medications such as procainamide and amantadine, there is a possibility of increased plasma concentration of one or both medications.
Pregnancy, breastfeeding, and fertility
If you are pregnant or breastfeeding, think you may be pregnant, or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medication.
Trimethoprim and sulfamethoxazole cross the placenta, and their safety in pregnant women has not been established. Trimethoprim/sulfamethoxazole should be avoided in pregnancy, unless the potential benefit to the mother is greater than the potential risk to the fetus; consideration may be given to supplementation with high doses of folate (up to 4 or 5 mg/day) if trimethoprim/sulfamethoxazole is used during pregnancy.
When Septrin is administered to the mother before birth, there may be a theoretical risk of kernicterus (severe neurological complication due to increased bilirubin levels in the blood) in the newborn. This theoretical risk is particularly important in children with a higher risk of hyperbilirubinemia, such as premature infants or those with glucose-6-phosphate dehydrogenase deficiency.
The administration of trimethoprim/sulfamethoxazole should be avoided in the final stages of pregnancy and in breastfeeding mothers, when the mothers or children have or are at particular risk of developing hyperbilirubinemia.
The medication is excreted in breast milk.
Driving and using machines
The influence of Septrin on the ability to drive and use machines is negligible or nonexistent.
Follow the instructions for administration of the medication contained in this leaflet or as indicated by your doctor. In case of doubt, consult your doctor or pharmacist again.
Remember to take your medication.
Your doctor will indicate the duration of your treatment with Septrin 80 mg/400 mg Tablets. Do not stop treatment before completion.
Septrin 80 mg/400 mg Tablets should be taken preferably after food intake. Take the tablets with a sufficient amount of liquid. If desired, the specified doses can be taken diluted in a small amount of water.
Your doctor will prescribe the most appropriate pharmaceutical form of Septrin according to age, weight, and dosage.
Septrin Pediatric 8 mg/40 mg/ml oral suspension and Septrin Pediatric 20 mg/100 mg tablets are the most suitable presentations for infants and children.
Standard dosage
Adults and children over 12 years:
Infants and children under 12 years: the pediatric forms of Septrin are recommended.
If after 7 days of treatment no clinical improvement is observed, the patient will be reevaluated.
As an alternative to the standard dosage, a treatment with 2 tablets of Septrin 80 mg/400 mg (160/800 mg of trimethoprim-sulfamethoxazole) every 12 hours for 3 days is suitable for the treatment of urinary tract infections and infectious diarrhea.
Special dosages
Elderly patients: (see section 2). If not otherwise specified, the standard dosage will be used.
Patients with renal insufficiency:
Adults and children over 12 years (no information is available for children under 12 years):
Creatinine clearance (ml/min) Recommended dosage
> 30 Standard dosage
15-30 Half of the standard dosage
< 15 Not recommended
Your doctor may perform blood tests every 2-3 days to measure the amount of medication in the blood.
Pneumocystis jiroveci (P. carinii) pneumonia
Treatment
Adults and children: 20 mg of trimethoprim and 100 mg of sulfamethoxazole/kg/day, in two or more divided doses, for two weeks.
Prophylaxis (prevention)
Adults:
The following dosing regimens can be used:
Children: in infants and children under 12 years, the pediatric forms of Septrin are recommended.
Toxoplasmosis
Primary prophylaxis (primary prevention)
Adults and children over 12 years:
Children: the pediatric forms of Septrin are recommended.
Treatment
Adults(no data are available for children): 5 mg/kg of trimethoprim/25 mg/kg of sulfamethoxazole/12 hours for 6 weeks.
Granuloma Inguinale (Donovanosis)
2 tablets of Septrin 80 mg/400 mg (160 mg of trimethoprim/800 mg of sulfamethoxazole) twice a day for a period of at least 3 weeks or until all lesions have completely disappeared.
Nocardiosis
10-15 mg/kg/day of trimethoprim/50-75 mg/kg/day of sulfamethoxazole in two or more divided doses for a period of 3-6 months. In immunocompromised patients, treatment should be more prolonged. All patients with central nervous system involvement should be treated for at least one year.
Brucellosis
Adults and children over 8 years:
2 tablets of Septrin 80 mg/400 mg every 12 hours (160 mg of trimethoprim/800 mg of sulfamethoxazole/12 hours) for 6 weeks.
Children under 8 years(in this group, it is considered the first choice of treatment): the pediatric forms of Septrin are recommended.
Melioidosis
8 mg/kg/day of trimethoprim and 40 mg/kg/day of sulfamethoxazole (maximum 320 mg of trimethoprim/1,600 mg of sulfamethoxazole) every 12 hours for 3-6 months.
If you take more Septrin 80 mg/400 mg Tablets than you should
Symptoms of overdose include: nausea, vomiting, dizziness, and confusion.
In acute overdose with trimethoprim, bone marrow depression has been observed.
If vomiting does not occur, it should be induced. Gastric lavage should be performed. Depending on the state of renal function, administration of fluids is recommended if urine elimination is low.
Both trimethoprim and sulfamethoxazole are dialyzable by hemodialysis. Peritoneal dialysis is not effective.
In case of overdose or accidental ingestion, consult the Toxicology Information Service. Phone: 91 562 04 20.
If you forget to take Septrin 80 mg/400 mg Tablets
Do not take a double dose to make up for forgotten doses.
Like all medicines, Septrin 80 mg/400 mg tablets may cause adverse effects, although not all people will experience them.
Severe Adverse Effects
Call emergency services immediately if you experience multiple symptoms such as fever, very low blood pressure, or increased heart rate after taking this medication, as it may be a symptom of shock.
The adverse effects described for Septrin 80 mg/400 mg tablets are classified by frequency and are as follows:
Hypoglycemia (decrease in blood glucose), hyponatremia (decrease in sodium in the blood), anorexia (metabolic disorder). Depression, hallucinations, aseptic meningitis, convulsions, peripheral neuritis (lesion and deterioration of peripheral nerves), ataxia (loss of coordination), vertigo, tinnitus (ringing in the ears), dizziness, cough, difficulty breathing, pulmonary infiltrates, glossitis (inflammation of the tongue), stomatitis (lesions in the mouth), pseudomembranous colitis (inflammation of the colon), pancreatitis (inflammation of the pancreas), hepatobiliary disorders (alteration of liver function), photosensitivity (skin reaction produced by interaction with light), exfoliative dermatitis (severe inflammation of the entire skin surface), fixed drug eruption (allergic reaction), erythema multiforme (allergic reaction affecting the skin), arthralgia (joint pain), myalgia (muscle pain), alteration of renal function, uveitis (inflammation of the eye). Skin rashes may appear that can threaten the patient's life (Stevens-Johnson syndrome, toxic epidermal necrolysis) (see section 2: Warnings and precautions).
In some cases, skin rashes have been observed that can threaten the patient's life, such as purple, raised, and painful blisters on the extremities and sometimes on the face and neck, with fever (Sweet's syndrome) (see section 2: Warnings and precautions).
Contact a doctor as soon as possible if you experience a severe skin reaction: a red and scaly rash with bumps under the skin and blisters (acute generalized exanthematous pustulosis). (See section 2: Warnings and precautions).
If you experience adverse effects, consult your doctor or pharmacist, even if they are adverse effects that do not appear in this leaflet.
Reporting of Adverse Effects:
If you experience any type of adverse effect, consult your doctor, pharmacist, or nurse, even if it is a possible adverse effect that does not appear in this leaflet. You can also report them directly through the Spanish Pharmacovigilance System for Human Use Medicines: www.notificaram.es. By reporting adverse effects, you can contribute to providing more information on the safety of this medication.
No special storage conditions are required.
Keep this medication out of the sight and reach of children.
Do not use this medication after the expiration date that appears on the packaging after CAD. The expiration date is the last day of the month indicated.
Medicines should not be disposed of through wastewater or household waste. Deposit the packaging and any unused medication in the SIGRE collection point at the pharmacy. In case of doubt, ask your pharmacist how to dispose of the packaging and any unused medication. This will help protect the environment.
Composition of Septrin 80 mg/400 mg Tablets
Appearance of the Product and Package Contents
Septrin 80 mg/400 mg tablets are white, round (with an approximate diameter of 11 mm), biconvex, and scored.
PVC/Aluminum blisters of 20 and 100 tablets.
Marketing Authorization Holder
TEOFARMA S.r.l.
Via F.lli Cervi, 8
27010 Valle Salimbene
Pavia – Italy
Manufacturer
Alcalá Farma, S.L
Avenida de Madrid 82, Alcalá de Henares
28802 Madrid Spain
Other Presentations
Packaging of 20 and 50 tablets.
Packaging of 20 and 100 tablets.
Container with 100 ml.
Date of the Last Revision of this Leaflet: July 2025
Detailed and updated information on this medication is available on the website of the Spanish Agency for Medicines and Health Products (AEMPS) http://www.aemps.gob.es/
The average price of SEPTRIN 80 mg/400 mg TABLETS in October, 2025 is around 7.24 EUR. Prices may vary depending on the region, pharmacy, and whether a prescription is required. Always check with a local pharmacy or online source for the most accurate information.