Trimethoprim

Trimethoprim

Clinical data
Pronunciation	/traɪˈmɛθəprɪm/
Trade names	Proloprim, Monotrim, Triprim, others
AHFS/Drugs.com	Monograph
MedlinePlus	a684025
License data	US FDA: Trimethoprim
Pregnancy category	AU: B3 US: C (Risk not ruled out)
Routes of administration	Oral
ATC code	J01EA01 (WHO) QJ51EA01 (WHO)
Legal status
Legal status	AU: S4 (Prescription only) CA: ℞-only UK: POM (Prescription only) US: ℞-only
Pharmacokinetic data
Bioavailability	90–100%
Protein binding	44%
Metabolism	hepatic
Biological half-life	8-12 hours
Excretion	Urine (50–60%), faeces (4%)
Identifiers
IUPAC name 5-(3,4,5-Trimethoxybenzyl)pyrimidine-2,4-diamine
CAS Number	738-70-5 Y
PubChem CID	5578
DrugBank	DB00440 Y
ChemSpider	5376 Y
UNII	AN164J8Y0X
KEGG	D00145 Y
ChEBI	CHEBI:45924 Y
ChEMBL	CHEMBL22 Y
PDB ligand	TOP (PDBe, RCSB PDB)
ECHA InfoCard	100.010.915
Chemical and physical data
Formula	C14H18N4O3
Molar mass	290.32 g/mol
3D model (Jmol)	Interactive image
SMILES COc1cc(cc(c1OC)OC)Cc2cnc(nc2N)N
InChI InChI=1S/C14H18N4O3/c1-19-10-5-8(6-11(20-2)12(10)21-3)4-9-7-17-14(16)18-13(9)15/h5-7H,4H2,1-3H3,(H4,15,16,17,18) Y Key:IEDVJHCEMCRBQM-UHFFFAOYSA-N Y

Trimethoprim (TMP) is an antibiotic used mainly in the treatment of bladder infections. Other uses include for middle ear infections and travelers' diarrhea. With sulfamethoxazole or dapsone it may be used for Pneumocystis pneumonia in people with HIV/AIDS. It is taken by mouth.

Common side effects include nausea, changes in taste, and rash. Rarely it may result in blood problems such as not enough platelets or white blood cells. May cause sun sensitivity. There is evidence of potential harm during pregnancy in some animals but not humans. It works by blocking folate metabolism via dihydrofolate reductase in some bacteria which results in their death.

Trimethoprim was first used in 1962. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. It is available as a generic medication and is not very expensive. In the United States 10 days of treatment is about 21 USD.

It is primarily used in the treatment of urinary tract infections, although it may be used against any susceptible aerobic bacterial species. It may also be used to treat and prevent Pneumocystis jiroveci pneumonia. It is generally not recommended for the treatment of anaerobic infections such as Clostridium difficile colitis (the leading cause of antibiotic-induced diarrhea). Trimethoprim has been used in trials to treat retinitis.