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Trimethoprim and sulfamethoxazole

National Institute of Allergy and Infectious Diseases (NIAID) · FDA-approved active Small molecule

Trimethoprim and sulfamethoxazole is a Sulfonamide antibiotic combination Small molecule drug developed by National Institute of Allergy and Infectious Diseases (NIAID). It is currently FDA-approved for Urinary tract infections, Pneumocystis jirovecii pneumonia (PCP) prophylaxis and treatment, Acute otitis media. Also known as: Septra®).

Trimethoprim and sulfamethoxazole is a fixed-dose combination antibiotic that inhibits bacterial folate synthesis by blocking two sequential enzymes in the pathway.

Trimethoprim and sulfamethoxazole is a fixed-dose combination antibiotic that inhibits bacterial folate synthesis by blocking two sequential enzymes in the pathway. Used for Urinary tract infections, Pneumocystis jirovecii pneumonia (PCP) prophylaxis and treatment, Acute otitis media.

At a glance

Generic nameTrimethoprim and sulfamethoxazole
Also known asSeptra®)
SponsorNational Institute of Allergy and Infectious Diseases (NIAID)
Drug classSulfonamide antibiotic combination
TargetDihydropteroate synthase and dihydrofolate reductase
ModalitySmall molecule
Therapeutic areaInfectious Disease
PhaseFDA-approved

Mechanism of action

Sulfamethoxazole inhibits bacterial dihydropteroate synthase, while trimethoprim inhibits dihydrofolate reductase. Together, they sequentially block the synthesis of dihydrofolate and tetrahydrofolate, which are essential cofactors for bacterial nucleotide synthesis. This synergistic dual inhibition is bactericidal against a broad spectrum of gram-positive and gram-negative bacteria.

Approved indications

Common side effects

Key clinical trials

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

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Frequently asked questions about Trimethoprim and sulfamethoxazole

What is Trimethoprim and sulfamethoxazole?

Trimethoprim and sulfamethoxazole is a Sulfonamide antibiotic combination drug developed by National Institute of Allergy and Infectious Diseases (NIAID), indicated for Urinary tract infections, Pneumocystis jirovecii pneumonia (PCP) prophylaxis and treatment, Acute otitis media.

How does Trimethoprim and sulfamethoxazole work?

Trimethoprim and sulfamethoxazole is a fixed-dose combination antibiotic that inhibits bacterial folate synthesis by blocking two sequential enzymes in the pathway.

What is Trimethoprim and sulfamethoxazole used for?

Trimethoprim and sulfamethoxazole is indicated for Urinary tract infections, Pneumocystis jirovecii pneumonia (PCP) prophylaxis and treatment, Acute otitis media, Traveler's diarrhea, Toxoplasmosis prophylaxis in immunocompromised patients.

Who makes Trimethoprim and sulfamethoxazole?

Trimethoprim and sulfamethoxazole is developed and marketed by National Institute of Allergy and Infectious Diseases (NIAID) (see full National Institute of Allergy and Infectious Diseases (NIAID) pipeline at /company/national-institute-of-allergy-and-infectious-diseases-niaid).

Is Trimethoprim and sulfamethoxazole also known as anything else?

Trimethoprim and sulfamethoxazole is also known as Septra®).

What drug class is Trimethoprim and sulfamethoxazole in?

Trimethoprim and sulfamethoxazole belongs to the Sulfonamide antibiotic combination class. See all Sulfonamide antibiotic combination drugs at /class/sulfonamide-antibiotic-combination.

What development phase is Trimethoprim and sulfamethoxazole in?

Trimethoprim and sulfamethoxazole is FDA-approved (marketed).

What are the side effects of Trimethoprim and sulfamethoxazole?

Common side effects of Trimethoprim and sulfamethoxazole include Rash, Nausea, Vomiting, Diarrhea, Headache, Stevens-Johnson syndrome.

What does Trimethoprim and sulfamethoxazole target?

Trimethoprim and sulfamethoxazole targets Dihydropteroate synthase and dihydrofolate reductase and is a Sulfonamide antibiotic combination.

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