Quick Facts

• Supports management of: Urinary tract infections (UTIs)
• Used for: Acute exacerbations of chronic bronchitis
• Indicated for: Certain forms of ear infections in pediatric patients
• Employed in: The treatment and prevention of Pneumocystis jirovecii pneumonia (PJP)
• May also address: Travelers’ diarrhea and shigellosis

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Cotrimoxazole Teva is a combination antimicrobial agent used to support the management of various bacterial infections. Its therapeutic function involves addressing organisms susceptible to its components.

The medication is indicated for acute urinary tract infections (UTIs) and certain acute episodes of chronic bronchitis in adults. It may be utilized to manage acute otitis media, which are certain ear infections, in pediatric patients.

Furthermore, the drug is prescribed for the treatment and prophylaxis (prevention) of Pneumocystis jirovecii pneumonia (PJP), a key opportunistic infection, particularly in individuals who are immunosuppressed. The agent also serves a role in addressing certain enteric infections, such as shigellosis and travelers’ diarrhea. Consult official guidance for a full overview of uses and risk information.

Regulatory References

1. NIH MedlinePlus guidance

Who Can and Cannot Use Cotrimoxazole Teva?

The eligibility profile for Cotrimoxazole Teva is strictly defined by regulatory health authorities, identifying populations for whom use is permitted, restricted, or absolutely prohibited.

Category	Eligibility Rule
General Use	Permitted in adults and children aged 2 months and older (FDA standard) or 6 weeks and older (EMA standard).
Absolute Contraindications	Prohibited for patients with known hypersensitivity to the components (sulfonamides or trimethoprim), severe liver or renal failure (Creatinine Clearance below 15 mL/min), and specific blood disorders like megaloblastic anemia due to folate deficiency, acute porphyria, and a history of drug-induced immune thrombocytopenia.
Age Prohibition	Use is contraindicated in infants less than two months of age for standard indications.
Reproductive Status	Use is contraindicated at term in pregnancy and generally not recommended during lactation, especially for high-risk infants.
Restrictions/Caution	Patients with moderate renal impairment (CrCl 15 to 30 mL/min) require modified dosing. Caution is strongly advised for elderly patients and individuals predisposed to folate deficiency or G6PD deficiency.

This structure ensures that eligibility is based solely on patient health status and age, in alignment with official regulatory labeling.

Interactions with other medicines and products

Cotrimoxazole Teva, a combination of Sulfamethoxazole and Trimethoprim, has officially documented interaction patterns that can affect the plasma exposure and toxicity of co-administered medicines.

Contraindicated Combinations

Co-administration with Dofetilide is strictly contraindicated. The Trimethoprim component inhibits the renal secretion of Dofetilide, leading to increased plasma concentrations and a serious risk of cardiac arrhythmia. Co-administration with Clozapine is also contraindicated by some regulatory authorities due to an increased risk of severe neutropenia.

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Pharmacokinetic and Pharmacodynamic Interactions

The medicine is documented to alter the clearance of several drugs. The Sulfamethoxazole component can inhibit the metabolism (CYP2C9) of Warfarin and Phenytoin, which potentiates the anticoagulant activity and prolongs the half-life of Phenytoin, respectively. Trimethoprim inhibits renal transporters, causing a documented increase in the exposure (AUC) of medicines like Lamivudine.

Co-administration with antifolates such as Methotrexate or Pyrimethamine results in an additive antifolate effect, increasing the risk of haematological toxicity. Combining with ACE Inhibitors or potassium supplements carries a documented risk of hyperkalaemia due to additive effects on potassium levels. Administration of Folinic Acid is known to interfere with the antimicrobial efficacy of Cotrimoxazole.

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Population-Specific Notes

Elderly patients taking Cotrimoxazole with Thiazide Diuretics are noted to have an increased risk of thrombocytopenia. This population also has a documented risk of elevated plasma Digoxin levels when co-administered with Trimethoprim.

Dual Sequential Blockade of Folic Acid Synthesis

The core mechanism involves the sequential inhibition of two enzymes—dihydropteroate synthase (DHPS) and dihydrofolate reductase (DHFR)—which are required for the production of Tetrahydrofolic acid ( FH4) in bacteria. This dual blockade selectively disrupts a pathway unique to microbes, initiating a mechanistic cascade that prevents continued bacterial proliferation.

Disruption of Bacterial Genetic Material

By depleting the FH4 co-factor, the drug prevents the bacteria from synthesizing the fundamental purine and pyrimidine bases required for building DNA and RNA. This functional deficit halts bacterial cell division and replication, a physiological consequence that results in bactericidal activity.

Mechanistic Selectivity and Constraints

The mechanism relies on selectivity, as human cells acquire folate from diet and possess a structurally distinct DHFR enzyme, resulting in a low Trimethoprim affinity. However, this effect is physiologically constrained by bacterial defense mechanisms, such as gene mutations in the target enzymes or the overproduction of the natural enzyme substrate, which reduce the drug's binding affinity and subsequent functional inhibition.

How to Use Cotrimoxazole Teva

Cotrimoxazole (Sulfamethoxazole/Trimethoprim) is administered according to standardized regimens. The medicine is available for both oral ingestion via tablets or liquid suspension and for Intravenous (IV) Infusion using a solution concentrate. The specific route and dose depend on the type of infection being addressed.

For most acute infections, such as urinary tract infections or chronic bronchitis exacerbations, the treatment duration is typically 10 to 14 days, following a standard dose, usually one Double-Strength tablet, taken twice daily (every 12 hours). Conversely, prophylaxis regimens, such as for the prevention of Pneumocystis jirovecii pneumonia (PJP), are designed for long-term use and may follow a schedule of once daily or three times per week on alternate days.

Administration and Dosage Principles

Standard requirements for use indicate that the oral dosage is often taken with food or a large amount of fluid to mitigate potential gastric irritation. If the IV concentrate is used, it must first be diluted in a compatible solution, such as 5% Dextrose in Water, and then administered via slow infusion over 60 to 90 minutes; rapid injection is strictly prohibited.

Population-Specific Rules

Dosing requires adjustment for specific patient groups. For pediatric patients over two months of age, the dose is determined based on the child's body weight. A reduction in dosage is required for patients with impaired renal function; for example, if Creatinine Clearance is between 15 and 30 mL/min, the standard dose should be halved. In the event of a missed oral dose, it should be taken as soon as possible, but not doubled, to resume the regular schedule.

Cotrimoxazole Teva: Research Evidence Overview

This overview summarizes the formal research base and clinical studies conducted for the combination of sulphamethoxazole and trimethoprim (Co-trimoxazole). Research has explored the drug's use primarily through Randomized Controlled Trials (RCTs) and systematic reviews, focusing on key indications.

Evidence for Urinary Tract Infections (UTIs)

Studies have investigated acute treatment and long-term prophylaxis in adults and children. Researchers applied short-term RCTs to monitor the eradication of bacteria and measured clinical cure (symptom resolution). Findings describe patterns observed in these studies, though current data are limited for frail older adult populations, and ongoing concern exists regarding evolving bacterial resistance patterns.

Evidence for Pneumocystis jirovecii Pneumonia (PJP)

Foundational studies and cohort data have examined the medication's use in PJP prophylaxis and, in acute treatment settings, monitored survival rates and hospital admission frequency in immunocompromised patients (including those with HIV). Research consistently notes the drug's use as a comparator agent in many treatment settings, but certainty remains low regarding the dosage required across all susceptible groups.

Evidence in Other Conditions and Populations

Research has also explored the drug's use in pediatric acute otitis media and in adults with acute exacerbations of chronic bronchitis (AECB). The evidence for these uses is characterized by shorter follow-up durations and mixed findings regarding bacteriologic eradication. Limited information is available for long-term outcomes across these indications. Furthermore, studies exploring complex comorbidities in older adults are limited, meaning subgroup findings are uncertain.

Research Gaps and Uncertainty

A major ongoing concern across all indications is the increasing microbial resistance to the drug's components, which was associated with reduced clinical response in some studies. Comparative evidence is lacking for its use against the newest antibiotic classes, and current data are still emerging in complex or frail patient subgroups, indicating that research is ongoing in these areas.

Common questions about Cotrimoxazole Teva (FAQ)

Q: What is Cotrimoxazole Teva used for?

A: Cotrimoxazole Teva is a combination of two antibiotic medicines, sulfamethoxazole and trimethoprim. It is used to address infections caused by certain types of bacteria, such as those affecting the:

• Urinary system (bladder and urinary tract)
• Respiratory system (e.g., bronchitis)
• Ears (e.g., otitis media)
• Intestines (e.g., certain types of diarrhea)

It is also used for the prevention and treatment of a specific type of pneumonia (Pneumocystis jirovecii pneumonia or PCP) in individuals with weakened immune systems.

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Q: Is Cotrimoxazole Teva effective against all infections?

A: No. As an antibiotic, Cotrimoxazole Teva is active only against bacteria and some other microorganisms. It is not effective against infections caused by viruses, such as the common cold or flu. Like all antibiotics, it is only suitable for infections where the responsible microorganism is known to be susceptible to this medicine.

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Q: What are the main contraindications for taking Cotrimoxazole Teva?

A: Cotrimoxazole Teva is generally not suitable for individuals with certain health conditions. You should not take this medicine if you have:

• A known allergy to sulfamethoxazole, trimethoprim, or any medicines containing a sulfonamide structure (like some diabetes or water tablets).
• Severe problems with liver function.
• Severe problems with kidney function.
• A history of certain blood disorders, such as megaloblastic anemia caused by folate deficiency.
• A rare inherited blood disorder called porphyria.

It is also generally not given to infants under six weeks of age.

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Q: Does Cotrimoxazole Teva cause sensitivity to sunlight?

A: Yes, a known effect of taking Cotrimoxazole Teva is photosensitivity, which means your skin may become more sensitive to sunlight and ultraviolet (UV) light. This may increase the risk of sunburn or rash during treatment.

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Q: What are some of the common or serious side effects I should be aware of?

A: Common side effects may include:

• Nausea or vomiting
• Diarrhea
• Headache
• Skin rashes (often mild)

Serious, though rare, side effects can occur, including severe skin reactions (like Stevens-Johnson syndrome or Toxic Epidermal Necrolysis), blood disorders, and severe allergic reactions. If you experience a severe rash, blistering of the skin, flu-like symptoms, difficulty breathing, or swelling of the face, stop taking the medicine and seek urgent medical attention.

Official Storage and Disposal Guidance

Cotrimoxazole (Sulfamethoxazole/Trimethoprim) must be stored according to specific regulatory requirements to maintain stability. The product should be kept at controlled room temperature (e.g., 20 C to 25 C / 68 F to 77 F), protected from freezing and excessive heat.

Protect all forms, particularly the suspension and tablets, from light by storing them in their original, tightly closed container and keeping them in the outer carton. The product must be kept out of the reach of children.

For disposal, unused or expired Cotrimoxazole should not be flushed down the toilet or poured down a drain. Instead, follow instructions on the label, or use a drug take-back program. If no program is available, mix the medication with an unappealing substance, place it in a sealed bag, and discard it in household trash.