The combination of trimethoprim and sulfamethoxazole in Bactrim acts against bacterial infections. The drug is effective in lesions of the respiratory tract, urinary tract and skin. It is used in bronchitis, cystitis and some types of pneumonia. It is distinguished by a wide spectrum of action and availability for different age groups. Dosage is determined by a doctor depending on the nature and severity of the disease. It is used to inhibit bacterial growth.
no RX
Dosage | Package | Per Item | Per Pack | Order |
480 mg |
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The drug is known under the trade name Bactrim. This is the registered name used to designate this drug on the pharmaceutical market.
The international nonproprietary name of Bactrim is co-trimoxazole. It reflects the combination of two active substances: sulfamethoxazole and trimethoprim, which provide a synergistic antibacterial effect.
Bactrim is available in several forms, which allows you to choose the best option for use depending on the age of the patient and the nature of the disease:
The variety of release forms makes the drug convenient for use both in outpatient and inpatient settings.
Bactrim contains two active ingredients:
Auxiliary ingredients vary depending on the form of release. In tablets, the following are used:
Suspension includes flavorings (e.g., strawberry), sorbitol as a sweetener, cellulose dispersible for structural stability. Solution for infusion contains sodium hydroxide, ethanol and water for injection.
Bactrim has bactericidal action due to the combined effect of two components. Sulfamethoxazole blocks the synthesis of dihydrofolic acid in bacteria, preventing the formation of purines and pyrimidines necessary for the reproduction of microorganisms. Trimethoprim complements this process by inhibiting the enzyme dihydrofolate reductase, which disrupts the conversion of dihydrofolic acid into tetrahydrofolic acid, a key element for the synthesis of DNA and RNA in bacteria. The synergy of these substances makes the drug highly effective against a wide range of pathogens.
Bactrim is active against Gram-positive bacteria (Streptococcus pneumoniae, Staphylococcus aureus) and Gram-negative microorganisms (Escherichia coli, Proteus spp., Klebsiella spp., Haemophilus influenzae). It is also effective against some protozoa, such as Pneumocystis jirovecii.
The pharmacokinetic parameters of Bactrim ensure its stable therapeutic action.
After oral administration, sulfamethoxazole and trimethoprim are rapidly absorbed in the upper gastrointestinal tract. The maximum concentration in the blood is reached in 1-4 hours. Bioavailability is about 90% for both components. Food intake slows absorption but does not reduce overall efficacy.
The two substances are well distributed in the body, penetrating the lungs, kidneys, prostate, bile, cerebrospinal fluid and saliva. Sulfamethoxazole binds to plasma proteins by 70%, trimethoprim - by 44%. This ensures sufficient concentration in the foci of infection.
Sulfamethoxazole is metabolized in the liver to form acetylated and glucuronated derivatives, most of which are inactive. Trimethoprim undergoes less metabolism, about 80% is excreted unchanged.
Trimethoprim is metabolized in the liver to form acetylated and glucuronated derivatives.
The drug is excreted predominantly by the kidneys through tubular filtration and tubule secretion. The half-life of sulfamethoxazole is 10-12 hours, that of trimethoprim - 8-10 hours. In patients with normal renal function about 60% of the dose is excreted with urine within 24 hours.
Bactrim is indicated for the treatment of infections caused by co-trimoxazole-sensitive microorganisms. The main indications include:
The drug is often used for the prevention of pneumocystis pneumonia in immunocompromised patients, including HIV patients.
The use of Bactrim is prohibited in the following conditions:
With caution, the drug is prescribed in glucose-6-phosphate dehydrogenase deficiency and thyroid disease.
Bactrim tablets are taken orally, drinking plenty of water (at least 200 ml), preferably after meals to reduce gastric irritation. The suspension is shaken before use, measured with a measuring spoon. The solution for infusion is diluted in 0.9% sodium chloride solution or 5% glucose and administered by intravenous drip over 60-90 minutes.
Dosage is determined by the severity of infection and the age of the patient:
In renal insufficiency, the dose is adjusted:
In hepatic insufficiency, monitoring of the condition is required, but there are no strict guidelines for dose reduction.
Bactrim may cause the following adverse reactions:
If serious symptoms occur, discontinue use and consult a physician.
Exceeding the dose is manifested by nausea, vomiting, headache, confusion, bone marrow depression, hyperkalemia.
In overdose:
Hemodialysis is partially effective in eliminating trimethoprim.
Bactrim may interact:
Alcohol increases toxic effects on the liver and kidneys and should be avoided. Food slows absorption but does not affect efficacy.
Bactrim is contraindicated in the first trimester of pregnancy because of the risk of teratogenic effects. In the second and third trimesters it is used only for vital indications. In lactation the drug penetrates into milk, which requires temporary cessation of feeding.
The drug may cause dizziness or confusion, so driving should be avoided in case of such symptoms.
In elderly patients more often side effects occur, especially in case of renal dysfunction. In children, the drug is used with caution, strictly observing the dosage by weight.