Prescription medicine
Trimethoprim First approved as Trimpex
Trimethoprim (Trimpex) is a prescription medicine with an FDA approval on record since 1980. FDA's NDC Directory lists it from 4 generic labelers, and pharmacies paid $1.31 per trimethoprim 100 mg tablet in the October 7, 2026 NADAC survey.
- Generic listed
Check it at the source: the trimethoprim FDA label on DailyMed (effective January 26, 2024, Dr. Reddy's Labratories Inc.); the NDA 17952 record on Drugs@FDA; every trimethoprim label on DailyMed.
Highlights of the record
FDA label of January 26, 2024; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026; NADAC October 7, 2026
Used for
From the label: indications and usageTo 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.
Forms and strengths
- 100 mg
Tablet.
On the market
- Earliest approval on file
- May 30, 1980 Trimpex 200, Roche; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- 6 first June 6, 1985; 3 with a marketed status in Drugs@FDA
- Labelers listed (NDC)
- 5 of which 4 under generic applications, 1 under brand applications, repackagers included
Supply and safety
- Pharmacy cost (NADAC)
- $1.31 per tablet Trimethoprim 100 mg tablet
- Shortage (FDA)
- No current entry
- Recalls by its makers (FDA)
- No recall recorded
- FAERS reports
- 11,719 through July 30, 2026
What is trimethoprim used for?
From the label: indications and usageTo 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. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy. […]
Conditions named in the indications of trimethoprim's FDA labels, with every medicine labeled for each:
From other trimethoprim labelsBacterial infections and Urinary tract infections: For the treatment of initial episodes of uncomplicated urinary tract infections due to susceptible strains of the following organisms:
FDA pharmacologic class: Dihydrofolate Reductase Inhibitor Antibacterial.
Source: FDA drug label (Trimethoprim), NDA018679 (Dr Reddys Labs Sa), as published by Dr. Reddy's Labratories Inc., effective January 26, 2024 (SPL set 73ccebc1-7412-2424-d62c-a5180ec52d81), via openFDA; the full label on DailyMed
Is there a generic for trimethoprim (Trimpex)?
The FDA approved the first generic trimethoprim on June 6, 1985. 6 generic applications are approved; 3 of them carry a current (not discontinued) marketing status in Drugs@FDA; that status is not evidence that the generic is on sale.
FDA's NDC Directory lists trimethoprim from 4 labelers under a generic (ANDA) application and from 1 brand labeler. A listing means the company has registered the product for sale; it does not show that every pharmacy stocks it.
- 1980 earliest approval on file
- 1985 first generic approved
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
What do pharmacies pay for trimethoprim (Trimpex)?
In CMS's NADAC survey of October 7, 2026, pharmacies paid $1.31 per Trimethoprim 100 mg tablet, down 18% from $1.60 on October 8, 2025. The chart's scale runs from the lowest to the highest price shown, not from zero. NADAC is what retail pharmacies paid their wholesalers, per unit, in CMS's monthly survey; what a patient pays depends on insurance and the pharmacy.
- Trimethoprim 100 mg tablet (generic)
| Strength and form | Brand or generic | Pharmacy cost | 30 tablets, or one pen or vial | 12-month change |
|---|---|---|---|---|
| Trimethoprim 100 mg tablet | Generic | $1.31 per tablet | $39.20 | -18% |
Source: CMS National Average Drug Acquisition Cost (NADAC) survey, October 7, 2026: what retail pharmacies paid per unit; not a counter price
What does the trimethoprim label say about other medicines?
The trimethoprim label names 1 other medicine in its interaction, contraindication or warning sections. The labels of 19 other medicines name trimethoprim. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Phenytoin | drug interactions | Drug Interactions Trimethoprim may inhibit the hepatic metabolism of phenytoin. |
Other labels that name trimethoprim
Source: FDA drug label (Trimethoprim), NDA018679 (Dr Reddys Labs Sa), as published by Dr. Reddy's Labratories Inc., effective January 26, 2024 (SPL set 73ccebc1-7412-2424-d62c-a5180ec52d81), via openFDA; the full label on DailyMed
What do FAERS reports show for trimethoprim?
The FDA Adverse Event Reporting System holds 11,719 reports that list trimethoprim among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 1,536 are coded as a death and 5,088 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.
Reports received each year
The most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026
What else is labeled for the same conditions as trimethoprim?
25 other medicines are given the same way (oral) and in the same FDA class as trimethoprim or labeled mainly for the same use (bacterial infections), the same class first. Bacterial infections lists all 51 medicines labeled for it, by any route. The first 8 are below. They are listed as records, not as substitutes: whether one can replace another is a prescriber's decision.
| Medicine | Shared indication | Generic labelers (oral) | Pharmacy cost | Shortage |
|---|---|---|---|---|
| Doxycycline | Bacterial infections, Urinary tract infections | 71 labelers | $0.118 per tablet 100 mg tablet | A presentation being discontinued |
| Amoxicillin | Bacterial infections | 38 labelers | $0.0788 per capsule 500 mg capsule | No current entry |
| Amoxicillin and clavulanate | Bacterial infections, Urinary tract infections | 31 labelers | $0.0693 per mL 600-42.9 mg/5 mL sus | No current entry |
| Azithromycin | Bacterial infections | 47 labelers | $0.266 per tablet 250 mg tablet | A presentation being discontinued |
| Cephalexin | Bacterial infections, Urinary tract infections | 36 labelers | $0.120 per capsule 500 mg capsule | No current entry |
| Nitrofurantoin | Bacterial infections, Urinary tract infections | 47 labelers | $0.165 per capsule 50 mg capsule | A presentation being discontinued |
| Metronidazole | Bacterial infections | 40 labelers | $0.102 per tablet 250 mg tablet | In shortage |
| Clindamycin | Bacterial infections | 40 labelers | $0.103 per capsule 150 mg capsule | In shortage |
Source: FDA drug labels (indications), NDC Directory, NADAC of October 7, 2026, FDA shortages (October 8, 2026)
What next?
- Other dihydrofolate reductase inhibitor antibacterials
- the pharmacologic class, with prices and generics
- Trimethoprim side effects
- the label's list beside FAERS reports
- Check an interaction
- what two or more labels say about each other