Sulfameth/Trimethoprim 800/160 Mg Tb

Sulfamethoxazole and trimethoprim is a combination antibiotic used to treat various types of bacterial infections, including urinary tract infections, bronchitis, and traveler’s diarrhea. The dosage of ⁸⁰⁰⁄₁₆₀ mg is a common strength for this medication, with 800 mg of sulfamethoxazole and 160 mg of trimethoprim.

Introduction to Sulfamethoxazole and Trimethoprim

Sulfamethoxazole and trimethoprim are two antibiotics that work together to combat bacterial infections. Sulfamethoxazole belongs to a class of antibiotics known as sulfonamides, which inhibit the growth and multiplication of bacteria by interfering with their ability to produce folic acid. Trimethoprim, on the other hand, is a dihydrofolate reductase inhibitor that blocks the conversion of folic acid to its active form, thereby interfering with bacterial DNA synthesis.

Mechanism of Action

The combination of sulfamethoxazole and trimethoprim is effective against a wide range of bacteria, including both Gram-positive and Gram-negative organisms. The sulfa component of the antibiotic, sulfamethoxazole, competes with para-aminobenzoic acid (PABA) for incorporation into folic acid, thereby inhibiting the growth of bacteria. Trimethoprim, meanwhile, inhibits the enzyme dihydrofolate reductase, which is necessary for the conversion of dihydrofolic acid to tetrahydrofolic acid. This synergistic effect allows the combination to be more effective than either component alone.

Pharmacokinetics

Sulfamethoxazole and trimethoprim are both well absorbed after oral administration, with peak serum concentrations achieved within 1-4 hours. The elimination half-life of sulfamethoxazole is approximately 10 hours, while that of trimethoprim is approximately 8-10 hours. The combination is excreted primarily in the urine, with a small amount also excreted in the feces.

Indications and Dosage

The ⁸⁰⁰⁄₁₆₀ mg dosage of sulfamethoxazole and trimethoprim is commonly used to treat various types of bacterial infections, including:

• Urinary tract infections (UTIs): 1 tablet every 12 hours for 10-14 days
• Bronchitis: 1 tablet every 12 hours for 14 days
• Traveler’s diarrhea: 1 tablet every 12 hours for 5-10 days

It is essential to complete the full prescribed course of treatment, even if symptoms improve before finishing the medication.

Side Effects and Precautions

Common side effects of sulfamethoxazole and trimethoprim include:

• Nausea and vomiting
• Diarrhea
• Abdominal pain
• Rash
• Itching

More severe side effects, such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and agranulocytosis, can occur but are rare. Patients with a history of allergic reactions to sulfonamides or trimethoprim should exercise caution when taking this medication.

Interactions and Contraindications

Sulfamethoxazole and trimethoprim can interact with various medications, including:

• Warfarin: increased risk of bleeding
• Methotrexate: increased risk of toxicity
• Phenytoin: decreased effectiveness of phenytoin

The combination is contraindicated in patients with a known hypersensitivity to sulfonamides or trimethoprim, as well as in those with severe renal impairment or marked hepatic dysfunction.

Conclusion

Sulfamethoxazole and trimethoprim is a widely used antibiotic combination effective against a range of bacterial infections. The ⁸⁰⁰⁄₁₆₀ mg dosage is commonly prescribed for urinary tract infections, bronchitis, and traveler’s diarrhea. While generally well-tolerated, the combination can cause side effects and interact with other medications. Patients should be aware of the potential risks and benefits and follow the prescribed dosage and treatment duration to ensure effective treatment and minimize the risk of complications.