Bactrim: Potent Dual-Antibiotic Therapy for Bacterial Infections
Bactrim
| Product dosage: 480mg | |||
|---|---|---|---|
| Package (num) | Per pill | Price | Buy |
| 90 | $0.46 | $41.00 (0%) | 🛒 Add to cart |
| 120 | $0.42 | $54.67 $50.00 (9%) | 🛒 Add to cart |
| 180 | $0.38 | $82.00 $68.00 (17%) | 🛒 Add to cart |
| 270 | $0.36 | $123.00 $97.00 (21%) | 🛒 Add to cart |
| 360 | $0.34
Best per pill | $164.00 $121.00 (26%) | 🛒 Add to cart |
Bactrim is a combination antibiotic medication containing sulfamethoxazole and trimethoprim. This synergistic formulation is designed to combat a wide spectrum of susceptible bacterial strains by sequentially inhibiting two crucial steps in bacterial folate synthesis. It is a cornerstone in the treatment of various common and opportunistic infections, particularly those affecting the urinary tract, respiratory system, and gastrointestinal tract. Its broad-spectrum efficacy and well-established pharmacokinetic profile make it a first-line choice for many clinicians in both outpatient and inpatient settings.
Features
- Dual-Antibiotic Formulation: Contains a fixed 5:1 ratio of sulfamethoxazole to trimethoprim for synergistic bactericidal activity.
- Broad-Spectrum Coverage: Effective against both Gram-positive and Gram-negative bacteria, including Staphylococcus aureus, Escherichia coli, Klebsiella species, Proteus mirabilis, Shigella, and Salmonella.
- Multiple Dosage Forms: Available in oral tablets (standard and double strength), oral suspension for pediatric use, and intravenous solution for severe infections.
- Bactericidal Mechanism: Works by sequentially blocking dihydrofolic acid synthesis (via sulfamethoxazole) and its reduction to tetrahydrofolic acid (via trimethoprim), effectively halting bacterial DNA and RNA production.
- Established Safety Profile: Decades of clinical use with well-documented pharmacokinetics and a predictable side effect profile.
Benefits
- Effective Treatment for Resistant Infections: The dual mechanism reduces the likelihood of bacterial resistance development compared to single-agent therapies.
- Rapid Onset of Action: Achieves therapeutic serum concentrations quickly, leading to prompt symptomatic relief in conditions like urinary tract infections and acute exacerbations of chronic bronchitis.
- Convenient Dosing Regimen: Typically administered twice daily, improving patient adherence and compliance over therapies requiring more frequent dosing.
- Proven Efficacy in Prophylaxis: Demonstrated effectiveness in preventing opportunistic infections in immunocompromised patients, particularly Pneumocystis jirovecii pneumonia in HIV/AIDS patients.
- Cost-Effective Therapy: As a generic medication, it provides significant cost savings compared to newer branded antibiotics while maintaining clinical effectiveness.
- Flexible Administration Options: Availability of oral suspension makes it suitable for pediatric populations who cannot swallow tablets.
Common use
Bactrim is indicated for the treatment of a variety of bacterial infections caused by susceptible microorganisms. Primary indications include urinary tract infections (including cystitis and pyelonephritis) caused by susceptible strains of E. coli, Klebsiella-Enterobacter, Proteus mirabilis, Proteus vulgaris, and Proteus morganii. It is also commonly prescribed for acute otitis media in children caused by Haemophilus influenzae or Streptococcus pneumoniae, acute exacerbations of chronic bronchitis in adults due to susceptible strains of Haemophilus influenzae or Streptococcus pneumoniae, and traveler’s diarrhea caused by enterotoxigenic E. coli. Additionally, Bactrim is the drug of choice for the treatment and prophylaxis of Pneumocystis jirovecii pneumonia in immunocompromised individuals, particularly those with HIV/AIDS. Off-label uses may include treatment of certain skin and soft tissue infections, nocardiosis, and toxoplasmosis prophylaxis.
Dosage and direction
Dosage must be individualized based on the type and severity of infection, renal function, and patient characteristics. For urinary tract infections and shigellosis in adults and children over 2 months: The usual adult dosage is 160 mg trimethoprim/800 mg sulfamethoxazole (one double-strength tablet) every 12 hours for 10-14 days. For children: 8 mg/kg trimethoprim and 40 mg/kg sulfamethoxazole per 24 hours, administered in two divided doses every 12 hours for 10 days. For acute otitis media in children: 8 mg/kg trimethoprim and 40 mg/kg sulfamethoxazole per 24 hours in two divided doses every 12 hours for 10 days. For Pneumocystis jirovecii pneumonia treatment: 15-20 mg/kg trimethoprim and 75-100 mg/kg sulfamethoxazole per 24 hours in equally divided doses every 6-8 hours for 14-21 days. For prophylaxis of Pneumocystis jirovecii pneumonia: 160 mg trimethoprim/800 mg sulfamethoxazole daily or three times weekly. Dosage adjustment is required in patients with renal impairment (creatinine clearance 15-30 mL/min): Use 50% of the standard dosage; if creatinine clearance is below 15 mL/min, use is not recommended. Tablets should be taken with a full glass of water, and patients should maintain adequate fluid intake to prevent crystalluria.
Precautions
Bactrim should be used with caution in patients with impaired renal or hepatic function, severe allergies or bronchial asthma, glucose-6-phosphate dehydrogenase (G6PD) deficiency, folate deficiency (e.g., elderly, chronic alcoholics), or porphyria. Regular monitoring of complete blood counts is recommended during prolonged therapy due to the risk of hematologic toxicity. Serum potassium should be monitored, especially in elderly patients and those taking angiotensin-converting enzyme inhibitors or potassium-sparing diuretics, due to the risk of hyperkalemia. Patients should be advised that Bactrim may cause photosensitivity reactions, and appropriate sun protection measures should be taken. Use during pregnancy should be avoided, particularly near term, due to the potential for kernicterus in the newborn. Caution is advised when administering to elderly patients, who may be more susceptible to adverse reactions, particularly severe skin reactions and bone marrow suppression.
Contraindications
Bactrim is contraindicated in patients with known hypersensitivity to trimethoprim, sulfonamides, or any component of the formulation. It should not be used in patients with documented megaloblastic anemia due to folate deficiency. Contraindicated in pregnancy at term and during the nursing period because sulfonamides may cause kernicterus in infants. Should not be used in infants less than 2 months of age due to the risk of kernicterus. Contraindicated in patients with severe hepatic damage or marked renal impairment (creatinine clearance less than 15 mL/min). Should not be used for the treatment of streptococcal pharyngitis due to inadequate efficacy and potential increased risk of rheumatic fever.
Possible side effect
Common side effects (≥1%) include nausea, vomiting, loss of appetite, and headache. Gastrointestinal disturbances such as diarrhea, abdominal pain, and glossitis may occur. Dermatological reactions including rash, pruritus, and photosensitivity are frequently reported. Less common but more serious adverse reactions include Stevens-Johnson syndrome, toxic epidermal necrolysis, agranulocytosis, aplastic anemia, thrombocytopenia, leukopenia, hemolytic anemia, megaloblastic anemia, hypoprothrombinemia, and methemoglobinemia. Hepatic reactions including hepatitis, cholestatic jaundice, and hepatic necrosis may occur. Renal toxicity including interstitial nephritis and renal failure has been reported. Other potential side effects include hyperkalemia, hyponatremia, aseptic meningitis, peripheral neuritis, ataxia, vertigo, tinnitus, and pancreatitis. Allergic reactions ranging from mild rash to anaphylaxis may occur.
Drug interaction
Bactrim may potentiate the effects of warfarin and other oral anticoagulants, requiring close monitoring of prothrombin time. It may enhance the hypoglycemic effects of sulfonylureas, potentially leading to hypoglycemia. Concurrent use with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers may increase the risk of hyperkalemia. Bactrim may increase serum levels of phenytoin, potentially leading to toxicity. It may decrease the efficacy of oral contraceptives; additional contraceptive methods are recommended. Concurrent use with methotrexate may increase methotrexate toxicity due to displacement from plasma protein binding sites. Bactrim may increase the risk of cyclosporine nephrotoxicity. Thiazide diuretics may increase the risk of thrombocytopenia in elderly patients. Concurrent use with drugs that cause bone marrow suppression may increase hematologic toxicity.
Missed dose
If a dose is missed, it should be taken as soon as remembered. However, if it is almost time for the next scheduled dose, the missed dose should be skipped and the regular dosing schedule resumed. Patients should not double the dose to make up for a missed dose. Maintaining consistent antibiotic levels is important for efficacy, so patients should be advised to try to take doses at evenly spaced intervals. If multiple doses are missed, patients should contact their healthcare provider for guidance on how to proceed with treatment.
Overdose
Symptoms of overdose may include nausea, vomiting, dizziness, headache, mental depression, confusion, and bone marrow depression. Massive overdose may result in jaundice, hepatocellular necrosis, thrombocytopenia, agranulocytosis, and crystalluria with possible renal failure. Treatment is supportive and symptomatic. Gastric lavage may be performed if ingestion was recent. Maintain adequate fluid intake to prevent crystalluria and acidify urine to promote excretion. Monitor blood counts and appropriate blood chemistries, including electrolytes. Hemodialysis may be moderately effective in eliminating both components, particularly in patients with renal impairment. Leucovorin may be administered in doses of 5-15 mg daily to reverse the folate antagonistic effects, particularly in cases of bone marrow suppression.
Storage
Store at controlled room temperature 20°-25°C (68°-77°F). Protect from light and moisture. Keep the container tightly closed. Do not freeze the oral suspension. Keep out of reach of children. Do not use after the expiration date printed on the packaging. Unused medication should be properly disposed of according to local regulations and should not be flushed down the toilet or poured into drains unless instructed to do so.
Disclaimer
This information is provided for educational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any new medication or changing your treatment regimen. The information provided here may not cover all possible uses, directions, precautions, drug interactions, or adverse effects. Your healthcare provider is the best source of information regarding your specific medical condition and treatment options. Never disregard professional medical advice or delay in seeking it because of something you have read in this product information.
Reviews
Clinical studies and decades of use demonstrate Bactrim’s efficacy in treating susceptible infections, with success rates typically exceeding 85% for urinary tract infections when caused by susceptible organisms. Many clinicians appreciate its reliable activity against common pathogens and cost-effectiveness compared to newer antibiotics. However, increasing bacterial resistance patterns, particularly among urinary pathogens, have somewhat limited its utility in some regions. Patient reviews often note effective resolution of symptoms but also frequently mention gastrointestinal side effects. The medical community generally regards Bactrim as a valuable antibiotic when used appropriately for indicated infections, with careful attention to contraindications and monitoring requirements.