Sulfameth/Trimethoprim 800/160 Mg

Sulfamethoxazole/Trimethoprim ⁸⁰⁰⁄₁₆₀ mg, commonly referred to as Bactrim, Septra, or cotrimoxazole, is a combination antibiotic that consists of two active ingredients: sulfamethoxazole and trimethoprim. This medication is used to treat a wide range of bacterial infections, including urinary tract infections, bronchitis, traveler’s diarrhea, methicillin-resistant Staphylococcus aureus (MRSA) skin infections, and certain types of pneumonia.

Mechanism of Action

Sulfamethoxazole and trimethoprim work together to inhibit the growth and reproduction of bacteria. Sulfamethoxazole belongs to the class of sulfonamide antibiotics, which work by inhibiting the synthesis of folic acid in bacteria, a compound that is essential for bacterial growth and reproduction. Trimethoprim, on the other hand, is a dihydrofolate reductase inhibitor, which further inhibits the synthesis of tetrahydrofolic acid, another crucial component for bacterial DNA synthesis. By combining these two mechanisms, sulfamethoxazole/trimethoprim effectively prevents bacteria from producing the necessary components for growth, thereby leading to the death of the bacteria.

Indications

This antibiotic is prescribed for various bacterial infections, including but not limited to:

• Urinary Tract Infections (UTIs): Effective against E. coli, Klebsiella, Proteus, and Enterobacter species.
• Acute Bronchitis: When caused by susceptible strains of Streptococcus pneumoniae or Haemophilus influenzae.
• Traveler’s Diarrhea: Due to susceptible strains of Enterobacteriaceae.
• Pneumocystis Jiroveci Pneumonia (PCP): For the treatment and prevention of PCP in patients with HIV/AIDS.
• MRSA Skin Infections: Including uncomplicated skin and skin structure infections.

Dosage and Administration

The dosage of sulfamethoxazole/trimethoprim varies depending on the type of infection being treated. For adults, the typical dosage for urinary tract infections and acute bronchitis is one sulfamethoxazole/trimethoprim DS (double strength) tablet (800 mg/160 mg) every 12 hours for 10 to 14 days. For the treatment of PCP, the dosage is typically one DS tablet every 12 hours for 14 to 21 days. It’s crucial to complete the full course of treatment as prescribed by the healthcare provider, even if symptoms improve before completing the medication.

Side Effects

Common side effects of sulfamethoxazole/trimethoprim include:

• Nausea and vomiting
• Diarrhea
• Abdominal pain
• Headache
• Rash
• Fever

More severe but rare side effects can include:

• Stevens-Johnson syndrome
• Toxic epidermal necrolysis
• Agranulocytosis
• Thrombocytopenia
• Severe hypersensitivity reactions

Contraindications and Precautions

Sulfamethoxazole/trimethoprim is contraindicated in patients with a known hypersensitivity to trimethoprim or sulfonamides. It should also be avoided in patients with severe renal impairment, when the creatinine clearance is less than 15 mL/min, and in patients with marked hepatic dysfunction. Caution is advised in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency, as sulfonamides may cause hemolysis. Patients with HIV/AIDS on this medication for PCP prophylaxis or treatment should be monitored for signs of toxicity.

Warnings and Interactions

This medication can interact with other drugs, including:

• Warfarin: Increases the risk of bleeding.
• Phenytoin: May increase phenytoin levels.
• Methotrexate: May increase the risk of methotrexate toxicity.
• Digoxin: May increase digoxin levels.

It is essential to consult a healthcare provider about all medications, supplements, and herbal products being taken before starting sulfamethoxazole/trimethoprim.

Conclusion

Sulfamethoxazole/trimethoprim ⁸⁰⁰⁄₁₆₀ mg is a potent antibiotic combination used for treating a variety of bacterial infections. Its effectiveness and relatively minimal side effect profile make it a common choice for physicians. However, as with any antibiotic, it is crucial to follow the prescribed dosage and complete the full treatment course to maximize effectiveness and minimize the risk of resistance and side effects. Additionally, monitoring for potential side effects and drug interactions is important to ensure safe and effective treatment.

Frequently Asked Questions