What Is Sulfameth/Trimethoprim 800/160? Treatment Guide

Sulfamethoxazole/Trimethoprim, commonly known as Bactrim, Septra, or Cotrim, is a combination antibiotic consisting of two active ingredients: Sulfamethoxazole (800mg) and Trimethoprim (160mg). This medication is primarily used to treat various bacterial infections by preventing the growth and spread of bacteria.

Introduction to Sulfamethoxazole/Trimethoprim

The combination of Sulfamethoxazole and Trimethoprim works synergistically. Sulfamethoxazole belongs to a class of drugs known as sulfonamides, which work by inhibiting the growth of bacteria. Trimethoprim, on the other hand, belongs to the class of dihydrofolate reductase inhibitors. It works by inhibiting the reduction of dihydrofolic acid to tetrahydrofolic acid, a reaction necessary for the synthesis of nucleic acids in bacteria. By combining these two drugs, the spectrum of antibacterial activity is widened, and the risk of resistance development is decreased.

Uses of Sulfamethoxazole/Trimethoprim

Sulfamethoxazole/Trimethoprim is used to treat a wide range of bacterial infections, including but not limited to:

• Urinary Tract Infections (UTIs): Including acute uncomplicated cystitis, acute pyelonephritis, and complicated UTIs.
• Ear Infections: Such as acute otitis media.
• Bronchitis: Acute exacerbations of chronic bronchitis.
• Traveler’s Diarrhea: Caused by susceptible strains of Escherichia coli.
• Pneumocystis jirovecii Pneumonia (PCP): For the treatment and prevention of PCP, a type of infection that occurs in people with weakened immune systems, such as those with HIV/AIDS.

Dosage and Administration

The dosage of Sulfamethoxazole/Trimethoprim varies depending on the type of infection being treated. For adults, the usual dosage for most infections is one Sulfamethoxazole/Trimethoprim DS (double strength) tablet (800mg/160mg) every 12 hours. However, for certain infections like PCP, the dosage is one DS tablet every 8 hours. It’s crucial to follow the exact dosage and schedule provided by the healthcare provider to ensure the infection is fully treated and to minimize the risk of side effects.

Side Effects and Precautions

While Sulfamethoxazole/Trimethoprim is effective against a wide range of bacterial infections, it can cause side effects. Common side effects include:

• Nausea and Vomiting
• Diarrhea
• Rash
• Increased Sensitivity to the Sun
• Fever
• Headache

Rare but serious side effects can include severe allergic reactions, liver damage, and blood disorders. It’s essential to monitor for these adverse reactions and seek medical help immediately if symptoms occur.

Contraindications and Warnings

Sulfamethoxazole/Trimethoprim should not be used in patients with a known hypersensitivity to sulfonamides or trimethoprim. It should also be avoided or used with caution in patients with certain medical conditions, such as severe renal impairment, marked hepatic dysfunction, or blood dyscrasias. Pregnant women, especially those in the late stages of pregnancy, should use this medication with caution and under the guidance of a healthcare provider due to the potential risk of kernicterus in the newborn.

Interaction with Other Medications

Sulfamethoxazole/Trimethoprim can interact with a variety of medications, including but not limited to:

• Warfarin: May increase the risk of bleeding.
• Phenytoin: May increase phenytoin levels.
• Methotrexate: May increase the risk of methotrexate toxicity.
• Diuretics: May increase the risk of hyperkalemia.

It’s crucial for patients to inform their healthcare provider about all medications they are taking before starting Sulfamethoxazole/Trimethoprim.

Conclusion

Sulfamethoxazole/Trimethoprim ⁸⁰⁰⁄₁₆₀ is a potent antibiotic used to treat a variety of bacterial infections. While it can be highly effective, it must be used with caution and under the guidance of a healthcare professional due to potential side effects and interactions with other medications. Always follow the exact dosage and administration schedule provided by the healthcare provider to ensure the best treatment outcomes and minimize risks.