Trimethoprim

Trimethoprim is a bacteriostatic antibiotic used mainly in the prophylaxis and treatment of urinary tract infections.Target: DHFRTrimethoprim (TMP), an inhibitor of dihydrofolate reductase, decreases the level of tetrahydrofolate supplying one-carbon units for biosynthesis of nucleotides, proteins, and panthotenate. TMP caused induction of DnaK, DnaJ, GroEL, ClpB, and IbpA/B Hsps. Among these Hsps, IbpA/B were most efficiently induced by TMP and coaggregated with the insoluble proteins [1]. Trimethoprim binds to dihydrofolate reductase and inhibits the reduction of dihydrofolic acid (DHF) to tetrahydrofolic acid (THF). THF is an essential precursor in the thymidine synthesis pathway and interference with this pathway inhibits bacterial DNA synthesis. Trimethoprim's affinity for bacterial dihydrofolate reductase is several thousand times greater than its affinity for human dihydrofolate reductase. Sulfamethoxazole inhibits dihydropteroate synthetase, an enzyme involved further upstream in the same pathway. Trimethoprim and sulfamethoxazole are commonly used in combination due to their synergistic effects. This drug combination also reduces the development of resistance that is seen when either drug is used alone [2].

Signaling Pathways >> Cell Cycle/DNA Damage >> Antifolate

Research Areas >> Inflammation/Immunology

[1]. Laskowska, E., et al., Trimethoprim induces heat shock proteins and protein aggregation in E. coli cells. Curr Microbiol, 2003. 47(4): p. 286-9.

[2]. Brogden, R.N., et al., Trimethoprim: a review of its antibacterial activity, pharmacokinetics and therapeutic use in urinary tract infections. Drugs, 1982. 23(6): p. 405-30.

Levomefolic acid | Folinic acid (Calcium) | Pralatrexate | Calcium Levofolinate | Calcium N5-methyltetrahydrofolate | Diaveridine | LY 254155 | LY309887

DATA ITEMS CITED :

24

MOLECULAR FORMULA :

C14-H18-N4-O3

MOLECULAR WEIGHT :

290.36

WISWESSER LINE NOTATION :

T6N CNJ BZ DZ E1R CO1 DO1 EO1

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Human - woman

DOSE/DURATION :

56 mg/kg/7D-I

TOXIC EFFECTS :

Kidney, Ureter, Bladder - hematuria Blood - other changes Musculoskeletal - joints

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Human - woman

DOSE/DURATION :

60 mg/kg/10D-I

TOXIC EFFECTS :

Blood - thrombocytopenia

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

200 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

1460 mg/kg

TOXIC EFFECTS :

Behavioral - somnolence (general depressed activity) Lungs, Thorax, or Respiration - acute pulmonary edema Nutritional and Gross Metabolic - weight loss or decreased weight gain

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

>5 gm/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

2764 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

1870 mg/kg

TOXIC EFFECTS :

Behavioral - convulsions or effect on seizure threshold Lungs, Thorax, or Respiration - acute pulmonary edema Lungs, Thorax, or Respiration - dyspnea

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

>5 gm/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

132 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LDLo - Lowest published lethal dose

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Mammal - dog

DOSE/DURATION :

90 mg/kg

TOXIC EFFECTS :

Vascular - BP lowering not characterized in autonomic section

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

31800 mg/kg/30D-I

TOXIC EFFECTS :

Blood - changes in bone marrow (not otherwise specified)

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Primate - monkey

DOSE/DURATION :

27300 mg/kg/13W-I

TOXIC EFFECTS :

Brain and Coverings - recordings from specific areas of CNS Nutritional and Gross Metabolic - weight loss or decreased weight gain Related to Chronic Data - death

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rabbit

DOSE/DURATION :

31800 mg/kg/30D-I

TOXIC EFFECTS :

Blood - changes in bone marrow (not otherwise specified) Related to Chronic Data - death

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

DOSE :

2250 mg/kg

SEX/DURATION :

female 11-13 day(s) after conception

TOXIC EFFECTS :

Reproductive - Fertility - post-implantation mortality (e.g. dead and/or resorbed implants per total number of implants) Reproductive - Effects on Embryo or Fetus - fetotoxicity (except death, e.g., stunted fetus)

MUTATION DATA

TEST SYSTEM :

Rodent - rat

DOSE/DURATION :

800 mg/kg/8D

REFERENCE :

JOURAA Journal of Urology. (Williams & Wilkins Co., 428 E. Preston St., Baltimore, MD 21202) V.1- 1917- Volume(issue)/page/year: 112,348,1974 *** REVIEWS *** TOXICOLOGY REVIEW HFHBAG Hartford Hospital Bulletin. (Hartford Hospital, 80 Seymour St., Hartford, CT 06115) V.1- 1938/39- Volume(issue)/page/year: 29,364,1974 *** NIOSH STANDARDS DEVELOPMENT AND SURVEILLANCE DATA *** NIOSH OCCUPATIONAL EXPOSURE SURVEY DATA : NOES - National Occupational Exposure Survey (1983) NOES Hazard Code - X4630 No. of Facilities: 918 (estimated) No. of Industries: 4 No. of Occupations: 9 No. of Employees: 21309 (estimated) No. of Female Employees: 16105 (estimated)