Trimethoprim 7mg/5ml oral suspension
Requires a prescription from a doctor or prescriber
Official documents, adverse reaction reporting, and safety monitoring
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Official medicine documents
Safety monitoring data
Yellow Card reports
The MHRA Yellow Card scheme collects reports of suspected side effects from healthcare professionals and patients. View the Drug Analysis Profile (iDAP) for real-world adverse reaction data.
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Suspected adverse reactions reported for Trimethoprim
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Interactive Drug Analysis Profiles for all medicines
Report a side effect
Submit a Yellow Card report to the MHRA
Data from the MHRA Yellow Card scheme. A reported reaction does not necessarily mean the medicine caused it. Contains public sector information licensed under the Open Government Licence v3.0.
EudraVigilance
The European Medicines Agency (EMA) collects suspected adverse reaction reports from across the EU/EEA through the EudraVigilance system. Search for safety data on this medicine.
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Suspected adverse reactions reported for Trimethoprim
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EudraVigilance data is published by the European Medicines Agency (EMA). A suspected adverse reaction is not necessarily caused by the medicine.
1 branded products available
WHO defined daily dose (DDD)
400 mg
Not a recommended dose. The DDD is the assumed average maintenance dose per day for a drug used for its main indication in adults. It is a statistical measure used for research and comparison purposes only.
Source: WHO Collaborating Centre for Drug Statistics Methodology, distributed via the NHS dm+d supplementary BNF/ATC mapping files (NHSBSA). Contains public sector information licensed under the Open Government Licence v3.0.
Therapeutically similar medicines
Similarity is based on WHO Anatomical Therapeutic Chemical (ATC) classification and on a factual NHS dm+d therapeutic-grouping code prefix. Source data: NHS dm+d via TRUD (OGL v3.0), WHO ATC/DDD Index.
NHS prescribing volume and spending trends
Guidelines from the National Institute for Health and Care Excellence
NICE clinical guidance(14)
Urinary tract infection (recurrent): antimicrobial prescribing (NG112)
Prostatitis (acute): antimicrobial prescribing (NG110)
Pyelonephritis (acute): antimicrobial prescribing (NG111)
Urinary tract infection (lower): antimicrobial prescribing (NG109)
Urinary tract infection (catheter-associated): antimicrobial prescribing (NG113)
Leg ulcer infection: antimicrobial prescribing (NG152)
Clostridium difficile infection: risk with broad-spectrum antibiotics (ESMPB1)
Point-of-care tests for urinary tract infections to improve antimicrobial prescribing: early value assessment (HTG674)
Chronic obstructive pulmonary disease (acute exacerbation): antimicrobial prescribing (NG114)
Diverticular disease: diagnosis and management (NG147)
Urinary tract infections in adults (QS90)
Complicated urinary tract infections: ceftolozane/tazobactam (ESNM74)
Acne vulgaris: management (NG198)
Patiromer for treating hyperkalaemia (TA623)
Source: National Institute for Health and Care Excellence (NICE). Contains public sector information licensed under the Open Government Licence v3.0.
Check stock at pharmacies and supply information
Pharmacy stock checkers
Search for this medicine at major UK pharmacy chains. These links open the retailer's own website — results depend on their current online catalogue.
Supply & safety information
Official UK regulator monitoring and safety alerts
Pharmacy links redirect to the retailer's own search and do not represent real-time stock levels. Shortage and safety information sourced from MHRA drug safety updates (gov.uk, Crown Copyright under OGL v3.0).
Codes for healthcare professionals and prescribing systems
These codes are used by healthcare IT systems and prescribers to identify this medicine.
NHS UK identifiers
Browse tools
SNOMED CT and dm+d codes from NHS TRUD (Technology Reference data Update Distribution), licensed under the Open Government Licence v3.0. BNF code shown is the factual mapping value distributed by NHS Business Services Authority (NHSBSA) in the dm+d supplementary file under OGL v3.0; it is not affiliated with, nor licensed from, the publishers of the British National Formulary. ATC codes from the WHO Collaborating Centre for Drug Statistics Methodology (whocc.no).
Active and completed clinical studies from ClinicalTrials.gov
Source: ClinicalTrials.gov, a database of the U.S. National Library of Medicine (NLM), National Institutes of Health (NIH). Data accessed via ClinicalTrials.gov API v2. Trial information is provided for research purposes and does not constitute medical advice.
Academic studies and reviews for this medicine's active substance
Showing the 50 most relevant studies.
Reviews & meta-analyses: 13 · Randomised trials: 12 · 1968–2026
Showing the 50 most relevant studies, sorted by most relevant.
David A. Talan, Walter E. Stamm, Thomas M. Hooton, et al.
PubMed, 2000
- Acute Disease
- Anti-Infective Agents
- Anti-Infective Agents, Urinary
Stefan Z. Wiktor, M. Sassan‐Morokro, A. Grant, et al.
Lancet, 1999
- HIV-1
- Anti-Infective Agents
- Hospitalization
X. Anglaret, G. Chêne, A. Attia, et al.
Lancet, 1999
- HIV-1
- Analysis of Variance
- Anti-Infective Agents
Sharon Safrin, Dianne M. Finkelstein, Judith Feinberg, et al.
Annals of Internal Medicine, 1996
- Anti-Infective Agents
- Clindamycin
- Dapsone
Masoud Soheilian, Mohammad-Mehdi Sadoughi, Mehdi Ghajarnia, et al.
Ophthalmology, 2005
- Antibodies, Protozoan
- Antiprotozoal Agents
- Chorioretinitis
J. Ko, C. Kang, P. Cornejo-Juárez, et al.
Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases, 2019
Marion E. T. McMurdo, Ishbel S. Argo, G. Phillips, et al.
Journal of Antimicrobial Chemotherapy, 2008
- Vaccinium macrocarpon
- Anti-Bacterial Agents
- Plant Extracts
G. Schmitz, David Bruner, R. Pitotti, et al.
Annals of emergency medicine, 2010
Ploenchan Chetchotisakd, Wirongrong Chierakul, Wipada Chaowagul, et al.
The Lancet, 2013
- Anti-Bacterial Agents
- Doxycycline
- Melioidosis
Yunivita V, Maharani AJ, Bernadus CA, et al.
2026
Sources: aggregated from Europe PMC (EMBL-EBI), OpenAlex, Crossref, PubMed and other open scholarly databases. Retracted articles are excluded. Study information is provided for research purposes and does not constitute medical advice.
Pharmacology and chemical data from DrugBank
Key facts
Drug status
Approved
Major interactions
68 found
Half-life
8-10 hours
Mechanism
Trimethoprim is a reversible inhibitor of dihydrofolate reductase, one of the pr…
Food interactions
None known
Human targets
1 target
Data: DrugBank · CC BY-NC 4.0
Pharmacokinetics at a glance
Absorption
3 days
[A191368]…
Half-life
8-10 hours
[L11890]
Protein binding
44%
[L11890]
Volume of distribution
Metabolism
65%
Elimination
10-20%
[L11893]…
Clearance
51.7 - 91.3 mL/min
[A191368]
Pharmacokinetic data: DrugBank · CC BY-NC 4.0
[L11893][L11890]
In various formulations in combination with [sulfamethoxazole], trimethoprim is indicated for the following infections caused by bacteria with documented susceptibility: urinary tract infections, acute otitis media in pediatric patients (when clinically indicated), acute exacerbations of chronic bronchitis in adults, enteritis caused by susceptible Shigella, prophylaxis and treatment of Pneumocystis jiroveci pneumonia, and travelers' diarrhea caused by enterotoxigenic E. coli.
[L11830][L11863]
Trimethoprim is available as an ophthalmic solution in combination with [polymyxin B] for the treatment of acute bacterial conjunctivitis, blepharitis, and blepharoconjunctivitis caused by susceptible bacteria.
[L11887]
Known interactions with other medications. Always consult a healthcare professional.
Showing 50 of 1254 interactions
[L11917]
Prescribing information for trimethoprim states that signs of overdose may be evident following ingestion of doses >1 gram, and may include nausea, vomiting, dizziness, headaches, mental depression, confusion, and bone marrow depression.
[L11893]
Treatment should consist of general supportive measures and gastric lavage, if applicable. Urinary acidification may increase renal elimination of trimethoprim. Hemodialysis is only moderately effective in eliminating trimethoprim and peritoneal dialysis is of no benefit.
[L11893]
Trimethoprim is often given in combination with sulfamethoxazole, which inhibits the preceding step in bacterial protein synthesis - given together, sulfamethoxazole and trimethoprim inhibit two consecutive steps in the biosynthesis of bacterial nucleic acids and proteins.[L11830] As a monotherapy trimethoprim is considered bacteriostatic, but in combination with sulfamethoxazole is thought to exert bactericidal activity.[L11887][A191089]
As antimicrobial susceptibility patterns are geographically distinct, local antibiograms should be consulted to ensure adequate coverage of relevant pathogens prior to use.
How the body processes this drug — absorption, distribution, metabolism, and elimination
[A191368]
Average peak serum concentrations of approximately 1 µg/mL (Cmax) are achieved within 1 to 4 hours (Tmax) following the administration of a single 100mg dose.
[L11893]
Trimethoprim appears to follow first-order pharmacokinetics,[A191368] as a single 200mg dose results in serum concentrations approximately double that of a 100mg dose.
[L11893]
The steady-state AUC of orally administered trimethoprim is approximately 30 mg/L·h.
[A191368]
[L11890]
[L11890]
[L11830]
Trimethoprim distributes efficiently into vaginal fluids, with observed concentrations approximately 1.6-fold higher than those seen in the serum.
[L11893]
It may pass the placental barrier and into breast milk.
[L11830]
Trimethoprim is also sufficiently excreted in the feces to markedly reduce and/or eliminate trimethoprim-susceptible fecal flora.
[L11893]
[A191149]
Minor products include N-oxide metabolites (<5%) and benzylic metabolites in even smaller quantities.
[A191149]
The parent drug is considered to be the therapeutically active form.
[L11893]
The majority of trimethoprim biotransformation appears to involve CYP2C9 and CYP3A4 enzymes, with CYP1A2 contributing to a lesser extent.
[A191149]
[L11893]
Following oral administration, 50% to 60% of trimethoprim is excreted in the urine within 24 hours, approximately 80% of which is unchanged parent drug.
[L11890]
[A191368]
Proteins and enzymes this drug interacts with in the body
Binds its own mRNA and that of DHFR2
Enzymes involved in drug metabolism — important for understanding drug interactions
Proteins that transport this drug across cell membranes
PMID:2897240 PMID:35970996 PMID:8898203 PMID:9038218 PMID:35507548
Catalyzes the flop of phospholipids from the cytoplasmic to the exoplasmic leaflet of the apical membrane. Participates mainly to the flop of phosphatidylcholine, phosphatidylethanolamine, beta-D-glucosylceramides and sphingomyelins .
PMID:8898203
Energy-dependent efflux pump responsible for decreased drug accumulation in multidrug-resistant cells PMID:2897240 PMID:35970996 PMID:9038218
PMID:16330770 PMID:17509534
Plays a physiological role in the excretion of cationic compounds including endogenous metabolites, drugs, toxins through the kidney and liver, into urine and bile respectively .
PMID:16330770 PMID:17495125 PMID:17509534 PMID:17582384 PMID:18305230 PMID:19158817 PMID:21128598 PMID:24961373
Mediates the efflux of endogenous compounds such as creatinine, vitamin B1/thiamine, agmatine and estrone-3-sulfate .
PMID:16330770 PMID:17495125 PMID:17509534 PMID:17582384 PMID:18305230 PMID:19158817 PMID:21128598 PMID:24961373
May also contribute to regulate the transport of cationic compounds in testis across the blood-testis-barrier (Probable)
Plays a physiological role in the excretion of drugs, toxins and endogenous metabolites through the kidney
ATC J04AM08
ATC J01EE03
ATC J01EA01
ATC J01EE01
ATC J01EE04
ATC J01EE02
ATC J01EE05
ATC J01EE07
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Show
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Linked compound data from DrugBank Open Data (CC BY-NC 4.0)
Trimethoprim
Additional database identifiers
Drugs Product Database (DPD)
8452
ChemSpider
5376
BindingDB
18069
PDB
TOP
ZINC
ZINC000006627681
GenBank Gene Database
J01609
GenBank Protein Database
146006
UniProt Accession
DYR_ECOLI
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2861
GenAtlas
DHFR
GeneCards
DHFR
GenBank Gene Database
J00140
GenBank Protein Database
182724
Guide to Pharmacology
2603
UniProt Accession
DYR_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2623
GenAtlas
CYP2C9
GeneCards
CYP2C9
GenBank Gene Database
AY341248
Guide to Pharmacology
1326
UniProt Accession
CP2C9_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2637
GenAtlas
CYP3A4
GeneCards
CYP3A4
GenBank Gene Database
M18907
Guide to Pharmacology
1337
UniProt Accession
CP3A4_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2596
GenAtlas
CYP1A2
GeneCards
CYP1A2
GenBank Gene Database
Z00036
Guide to Pharmacology
1319
UniProt Accession
CP1A2_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2622
GenAtlas
CYP2C8
GeneCards
CYP2C8
GenBank Gene Database
M17397
Guide to Pharmacology
1325
UniProt Accession
CP2C8_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:40
GenAtlas
ABCB1
GeneCards
ABCB1
GenBank Gene Database
M14758
GenBank Protein Database
307180
Guide to Pharmacology
768
UniProt Accession
MDR1_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:25588
GeneCards
SLC47A1
GenBank Gene Database
AK001709
GenBank Protein Database
7023138
Guide to Pharmacology
1216
UniProt Accession
S47A1_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:26439
GeneCards
SLC47A2
Guide to Pharmacology
1217
UniProt Accession
S47A2_HUMAN
DrugBank citations
If you use DrugBank data in your research, please cite the following publications:
Show earlier publications
Structured knowledge from the free knowledge base
ATC classifications (Wikidata)
Linked open data from Wikidata (Q422665), a free and open knowledge base operated by the Wikimedia Foundation. Data is available under the Creative Commons CC0 1.0 Public Domain Dedication. WHO INN from the World Health Organization.