pharmacopeia
GET
/api/v1/drug/trimethoprim
2D structure
5-[(3,4,5-trimethoxyphenyl)methyl]pyrimidine-2,4-diamine
SMILES COC1=CC(=CC(=C1OC)OC)CC2=CN=C(N=C2N)N
InChIKey IEDVJHCEMCRBQM-UHFFFAOYSA-N

Mechanism of action

Sourced from openFDA

Mechanism-of-action classes: Cytochrome P450 2C8 Inhibitors; Dihydrofolate Reductase Inhibitors; Folic Acid Metabolism Inhibitors; Organic Cation Transporter 2 Inhibitors.

Cytochrome P450 2C8Dihydrofolate ReductaseFolic Acid MetabolismOrganic Cation Transporter 2

Indications

Sourced from openFDA
  • & USAGE To reduce the development of drug-resistant bacteria and maintain the effectiveness of trimethoprim tablets, USP and other antibacterial drugs, trimethoprim tablets, USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy.

Contraindications

Sourced from openFDA
  • Trimethoprim is contraindicated in individuals hypersensitive to trimethoprim and in those with documented megaloblastic anemia due to folate deficiency.contraindicated

Dosage & administration

Sourced from openFDA

DOSAGE & ADMINISTRATION The usual oral adult dosage is 100 mg of trimethoprim every 12 hours or 200 mg of trimethoprim every 24 hours, each for 10 days. The use of trimethoprim in patients with a creatinine clearance of less than 15 mL/min is not recommended. For patients with a creatinine clearance of 15 to 30 mL/min, the dose should be 50 mg every 12 hours.

Warnings & precautions

Sourced from openFDA

Serious hypersensitivity reactions have been reported rarely in patients on trimethoprim therapy. Trimethoprim has been reported rarely to interfere with hematopoiesis, especially when administered in large doses and/or for prolonged periods. The presence of clinical signs such as sore throat, fever, pallor, or purpura may be early indications of serious blood disorders (see OVERDOSAGE , Chronic ). Complete blood counts should be obtained if any of these signs are noted in a patient receiving trimethoprim and the drug discontinued if a significant reduction in the count of any formed blood element is found. Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including trimethoprim tablets, USP, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile. C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents. If CDAD is suspected or confirmed, ongoing antiobiotic use not directed against C. difficile may need to be discontinued.

Adverse reactions

Sourced from openFDA

The adverse effects encountered most often with trimethoprim were rash and pruritus. Dermatologic Rash, pruritus, and phototoxic skin eruptions. At the recommended dosage regimens of 100 mg b.i.d. or 200 mg q.d., each for 10 days, the incidence of rash is 2.9% to 6.7%. In clinical studies which employed high doses of trimethoprim, an elevated incidence of rash was noted. These rashes were maculopapular, morbilliform, pruritic, and generally mild to moderate, appearing 7 to 14 days after the initiation of therapy. Hypersensitivity Rare reports of exfoliative dermatitis, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis (Lyell Syndrome), and anaphylaxis have been received. Gastrointestinal Epigastric distress, nausea, vomiting, and glossitis. Elevation of serum transaminase and bilirubin has been noted, but the significance of this finding is unknown. Cholestatic jaundice has been rarely reported. Hematologic Thrombocytopenia, leukopenia, neutropenia, megaloblastic anemia, and methemoglobinemia. Metabolic Hyperkalemia, hyponatremia. Neurologic Aseptic meningitis has been rarely reported. Miscellaneous Fever, and increases in BUN and serum creatinine levels.

Use in specific populations

Sourced from openFDA

Pregnancy Teratogenic Effects Pregnancy category C Trimethoprim has been shown to be teratogenic in the rat when given in doses 40 times the human dose. In some rabbit studies, the overall increase in fetal loss (dead and resorbed and malformed conceptuses) was associated with doses six times the human therapeutic dose. While there are no large, well-controlled studies on the use of trimethoprim in pregnant women, Brumfitt and Pursell, 3 in a retrospective study, reported the outcome of 186 pregnancies during which the mother received either placebo or trimethoprim in combination with sulfamethoxazole. The incidence of congenital abnormalities was 4.5% (3 of 66) in those who received placebo and 3.3% (4 of 120) in those receiving trimethoprim and sulfamethoxazole. There were no abnormalities in the 10 children whose mothers received the drug during the first trimester. In a separate survey, Brumfitt and Pursell also found no congenital abnormalities in 35 children whose mothers had received trimethoprim and sulfamethoxazole at the time of conception or shortly thereafter. Because trimethoprim may interfere with folic acid metabolism, trimethoprim should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Overdosage

Sourced from openFDA

Acute Signs of acute overdosage with trimethoprim may appear following ingestion of 1 gram or more of the drug and include nausea, vomiting, dizziness, headaches, mental depression, confusion, and bone marrow depression (see Chronic subsection). Treatment consists of gastric lavage and general supportive measures. Acidification of the urine will increase renal elimination of trimethoprim. Peritoneal dialysis is not effective and hemodialysis only moderately effective in eliminating the drug. Chronic Use of trimethoprim at high doses and/or for extended periods of time may cause bone marrow depression manifested as thrombocytopenia, leukopenia, and/or megaloblastic anemia. If signs of bone marrow depression occur, trimethoprim should be discontinued and the patient should be given leucovorin; 5 to 15 mg leucovorin daily has been recommended by some investigators.

Approval history

Sourced from openFDA
  • Jul 30, 1973NDANDA017377Sun Pharm Industries
  • Jul 30, 1982NDANDA018679Dr Reddys Labs Sa
  • Jan 7, 1983NDANDA018615Pharm Assoc
  • Aug 25, 1986ANDAANDA071017Sun Pharm Industries
  • Oct 31, 1991ANDAANDA073303Teva Pharms Usa
  • Feb 14, 1997ANDAANDA064120Bausch And Lomb Inc
  • Apr 13, 1998ANDAANDA064211Sandoz
  • Jan 27, 2005ANDAANDA076899Amneal Pharms Ny

FAERS reports

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Reference statistics only. FAERS reports are voluntarily submitted and are not incidence rates, safety signals, or causal evidence. Counts reflect reporting volume — how often a reaction was reported, not how often it occurs. For decision-grade use, consult openFDA and the FAERS Public Dashboard directly.
93,595 total reports matchedLatest report Share = reports listing the reaction ÷ total matched reports. Rows can sum to >100% because a single report often lists multiple reactions.
  1. 1Pyrexia6,8377.3%
  2. 2Off Label Use6,1726.6%
  3. 3Fatigue5,8616.3%
  4. 4Diarrhoea5,6036.0%
  5. 5Nausea5,5876.0%
  6. 6Dyspnoea4,9855.3%
  7. 7Rash4,9635.3%
  8. 8Pain4,5154.8%
  9. 9Vomiting4,3884.7%
  10. 10Drug Ineffective4,2494.5%
  11. 11Headache3,9044.2%
  12. 12Pneumonia3,7594.0%
  13. 13Drug Hypersensitivity3,5993.8%
  14. 14Pruritus3,3693.6%
  15. 15Acute Kidney Injury3,3623.6%

Literature

View JSON

Recent PubMed references pinned to Trimethoprim as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

Clinical trials

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The 10 most recently updated of 287 ClinicalTrials.gov registrations naming Trimethoprim as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

Frequently asked questions

How does Trimethoprim work?
Mechanism-of-action classes: Cytochrome P450 2C8 Inhibitors; Dihydrofolate Reductase Inhibitors; Folic Acid Metabolism Inhibitors; Organic Cation Transporter 2 Inhibitors.
What is Trimethoprim used for?
According to FDA labeling, Trimethoprim carries indications including: & USAGE To reduce the development of drug-resistant bacteria and maintain the effectiveness of trimethoprim tablets, USP and other antibacterial drugs, trimethoprim tablets, USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
What class of drug is Trimethoprim?
Trimethoprim is classified as Trimethoprim and derivatives, Dihydrofolate Reductase Inhibitor Antibacterial, Cytochrome P450 2C8 Inhibitors, Dihydrofolate Reductase Inhibitors, Folic Acid Metabolism Inhibitors, Organic Cation Transporter 2 Inhibitors, Increased Cellular Death.
What are the brand names for Trimethoprim?
Trimethoprim is marketed under brand names including Bactrim, Equisul SDT, Primsol, Sulfatrim, Uniprim.
What are the contraindications for Trimethoprim?
Trimethoprim labeling lists contraindications including: Trimethoprim is contraindicated in individuals hypersensitive to trimethoprim and in those with documented megaloblastic anemia due to folate deficiency.. Always consult the full prescribing information and a clinician.
Note. Data for trimethoprim is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.

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