DRUGS & SUPPLEMENTS
INDICATIONS AND USAGE
To reduce the development of drug-resistant bacteria and maintain the effectiveness of Trimethoprim tablets, USP and other antibacterial drugs, Trimethoprim tablets, USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.
For the treatment of initial episodes of uncomplicated urinary tract infections due to susceptible strains of the following organisms: Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Enterobacter species, and coagulase-negative Staphylococcus species, including S. saprophyticus.
Cultures and susceptibility tests should be performed to determine the susceptibility of the bacteria to Trimethoprim. Therapy may be initiated prior to obtaining the results of these tests.
Trimethoprim is contraindicated in individuals hypersensitive to Trimethoprim and in those with documented megaloblastic anemia due to folate deficiency.
Serious hypersensitivity reactions have been reported rarely in patients on Trimethoprim therapy. Trimethoprim has been reported rarely to interfere with hematopoiesis, especially when administered in large doses and/or for prolonged periods.
The presence of clinical signs such as sore throat, fever, pallor, or purpura may be early indications of serious blood disorders (see OVERDOSAGE, Chronic).
Complete blood counts should be obtained if any of these signs are noted in a patient receiving Trimethoprim and the drug discontinued if a significant reduction in the count of any formed blood element is found.
Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including Trimethoprim tablets, USP, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile.
C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.
If CDAD is suspected or confirmed, ongoing antiobiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.
Prescribing Trimethoprim tablets, USP in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.
Trimethoprim should be given with caution to patients with possible folate deficiency. Folates may be administered concomitantly without interfering with the antibacterial action of Trimethoprim. Trimethoprim should also be given with caution to patients with impaired renal or hepatic function.
Information for Patients
Patients should be counseled that antibacterial drugs including Trimethoprim tablets, USP should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When Trimethoprim tablets, USP are prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by Trimethoprim tablets, USP or other antibacterial drugs in the future.
Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued. Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with and without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic. If this occurs, patients should contact their physician as soon as possible.
Trimethoprim may inhibit the hepatic metabolism of phenytoin. Trimethoprim, given at a common clinical dosage, increased the phenytoin half-life by 51% and decreased the phenytoin metabolic clearance rate by 30%. When administering these drugs concurrently, one should be alert for possible excessive phenytoin effect.
Drug/Laboratory Test Interactions
Trimethoprim can interfere with a serum methotrexate assay as determined by the Competitive Binding Protein Technique when a bacterial dihydrofolate reductase is used as the binding protein. No interference occurs, however, if methotrexate is measured by a radioimmunoassay (RIA).
The presence of Trimethoprim may also interfere with the Jaffé alkaline picrate reaction assay for creatinine, resulting in overestimations of about 10% in the range of normal values.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Long-term studies in animals to evaluate carcinogenic potential have not been conducted with Trimethoprim.
Trimethoprim was demonstrated to be nonmutagenic in the Ames assay. In studies at two laboratories, no chromosomal damage was detected in cultured Chinese hamster ovary cells at concentrations approximately 500 times human plasma levels; at concentrations approximately 1000 times human plasma levels in these same cells, a low level of chromosomal damage was induced at one of the laboratories. No chromosomal abnormalities were observed in cultured human leukocytes at concentrations of Trimethoprim up to 20 times human steady-state plasma levels. No chromosomal effects were detected in peripheral lymphocytes of human subjects receiving 320 mg of Trimethoprim in combination with up to 1600 mg of sulfamethoxazole per day for as long as 112 weeks.
Impairment of Fertility
No adverse effects on fertility or general reproductive performance were observed in rats given Trimethoprim in oral dosages as high as 70 mg/kg/day for males and 14 mg/kg/day for females.
Pregnancy category C
Trimethoprim has been shown to be teratogenic in the rat when given in doses 40 times the human dose. In some rabbit studies, the overall increase in fetal loss was associated with doses six times the human therapeutic dose.
While there are no large, well-controlled studies on the use of Trimethoprim in pregnant women, Brumfitt and Pursell,3 in a retrospective study, reported the outcome of 186 pregnancies during which the mother received either placebo or Trimethoprim in combination with sulfamethoxazole. The incidence of congenital abnormalities was 4.5% (3 of 66) in those who received placebo and 3.3% (4 of 120) in those receiving Trimethoprim and sulfamethoxazole. There were no abnormalities in the 10 children whose mothers received the drug during the first trimester. In a separate survey, Brumfitt and Pursell also found no congenital abnormalities in 35 children whose mothers had received Trimethoprim and sulfamethoxazole at the time of conception or shortly thereafter.
Because Trimethoprim may interfere with folic acid metabolism, Trimethoprim should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
The oral administration of Trimethoprim to rats at a dose of 70 mg/kg/day commencing with the last third of gestation and continuing through parturition and lactation caused no deleterious effects on gestation or pup growth and survival.
Trimethoprim is excreted in human milk. Because Trimethoprim may interfere with folic acid metabolism, caution should be exercised when Trimethoprim is administered to a nursing woman.
Safety and effectiveness in pediatric patients below the age of 2 months have not been established. The effectiveness of Trimethoprim as a single agent has not been established in pediatric patients under 12 years of age.
Clinical studies of Trimethoprim tablets did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience4,5 has not identified differences in response between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy.
Case reports of hyperkalemia in elderly patients receiving trimethoprim-sulfamethoxazole have been published.6 Trimethoprim is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor potassium concentrations and to monitor renal function by calculating creatinine clearance.
The adverse effects encountered most often with Trimethoprim were rash and pruritus.
Rash, pruritus, and phototoxic skin eruptions. At the recommended dosage regimens of 100 mg b.i.d. or 200 mg q.d., each for 10 days, the incidence of rash is 2.9% to 6.7%. In clinical studies which employed high doses of Trimethoprim, an elevated incidence of rash was noted. These rashes were maculopapular, morbilliform, pruritic, and generally mild to moderate, appearing 7 to 14 days after the initiation of therapy.
Rare reports of exfoliative dermatitis, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, and anaphylaxis have been received.
Epigastric distress, nausea, vomiting, and glossitis. Elevation of serum transaminase and bilirubin has been noted, but the significance of this finding is unknown. Cholestatic jaundice has been rarely reported.
Thrombocytopenia, leukopenia, neutropenia, megaloblastic anemia, and methemoglobinemia.
Aseptic meningitis has been rarely reported.
Fever, and increases in BUN and serum creatinine levels.
Signs of acute overdosage with Trimethoprim may appear following ingestion of 1 gram or more of the drug and include nausea, vomiting, dizziness, headaches, mental depression, confusion, and bone marrow depression.
Treatment consists of gastric lavage and general supportive measures. Acidification of the urine will increase renal elimination of Trimethoprim. Peritoneal dialysis is not effective and hemodialysis is only moderately effective in eliminating the drug.
Use of Trimethoprim at high doses and/or for extended periods of time may cause bone marrow depression manifested as thrombocytopenia, leukopenia, and/or megaloblastic anemia. If signs of bone marrow depression occur, Trimethoprim should be discontinued and the patient should be given leucovorin; 5 to 15 mg leucovorin daily has been recommended by some investigators.
DOSAGE AND ADMINISTRATION
The usual oral adult dosage is 100 mg of Trimethoprim every 12 hours or 200 mg of Trimethoprim every 24 hours, each for 10 days. The use of Trimethoprim in patients with a creatinine clearance of less than 15 mL/min is not recommended. For patients with a creatinine clearance of 15 to 30 mL/min, the dose should be 50 mg every 12 hours.
Trimethoprim tablets, USP, 100 mg: White, round, convex tablet, debossed “9”, scored, “3” on one side and debossed “21 58” on the other, in bottles of 100.
Store at 20° to 25°C (68° to 77°F).
Dispense in a tight, light-resistant container as defined in the USP with a child-resistant closure (as required).
Manufactured In Canada By:
TEVA CANADA LIMITED
Toronto, Canada M1B 2K9
TEVA PHARMACEUTICALS USA, INC.
North Wales, PA 19454
Rev. K 6/2016
Trimethoprim pharmaceutical active ingredients containing related brand and generic drugs:
Active ingredient is the part of the drug or medicine which is biologically active. This portion of the drug is responsible for the main action of the drug which is intended to cure or reduce the symptom or disease. The other portions of the drug which are inactive are called excipients; there role is to act as vehicle or binder. In contrast to active ingredient, the inactive ingredient's role is not significant in the cure or treatment of the disease. There can be one or more active ingredients in a drug.
Trimethoprim available forms, composition, doses:
Form of the medicine is the form in which the medicine is marketed in the market, for example, a medicine X can be in the form of capsule or the form of chewable tablet or the form of tablet. Sometimes same medicine can be available as injection form. Each medicine cannot be in all forms but can be marketed in 1, 2, or 3 forms which the pharmaceutical company decided based on various background research results.
Composition is the list of ingredients which combinedly form a medicine. Both active ingredients and inactive ingredients form the composition. The active ingredient gives the desired therapeutic effect whereas the inactive ingredient helps in making the medicine stable.
Doses are various strengths of the medicine like 10mg, 20mg, 30mg and so on. Each medicine comes in various doses which is decided by the manufacturer, that is, pharmaceutical company. The dose is decided on the severity of the symptom or disease.
Trimethoprim destination | category:
Destination is defined as the organism to which the drug or medicine is targeted. For most of the drugs what we discuss, human is the drug destination.
Drug category can be defined as major classification of the drug. For example, an antihistaminic or an antipyretic or anti anginal or pain killer, anti-inflammatory or so.
Trimethoprim Anatomical Therapeutic Chemical codes:
A medicine is classified depending on the organ or system it acts [Anatomical], based on what result it gives on what disease, symptom [Therapeutical], based on chemical composition [Chemical]. It is called as ATC code. The code is based on Active ingredients of the medicine. A medicine can have different codes as sometimes it acts on different organs for different indications. Same way, different brands with same active ingredients and same indications can have same ATC code.
Trimethoprim pharmaceutical companies:
Pharmaceutical companies are drug manufacturing companies that help in complete development of the drug from the background research to formation, clinical trials, release of the drug into the market and marketing of the drug.
Researchers are the persons who are responsible for the scientific research and is responsible for all the background clinical trials that resulted in the development of the drug.
Frequently asked QuestionsCan i drive or operate heavy machine after consuming Trimethoprim?
Depending on the reaction of the Trimethoprim after taken, if you are feeling dizziness, drowsiness or any weakness as a reaction on your body, Then consider Trimethoprim not safe to drive or operate heavy machine after consumption. Meaning that, do not drive or operate heavy duty machines after taking the capsule if the capsule has a strange reaction on your body like dizziness, drowsiness. As prescribed by a pharmacist, it is dangerous to take alcohol while taking medicines as it exposed patients to drowsiness and health risk. Please take note of such effect most especially when taking Primosa capsule. It's advisable to consult your doctor on time for a proper recommendation and medical consultations.Is Trimethoprim addictive or habit forming?
Medicines are not designed with the mind of creating an addiction or abuse on the health of the users. Addictive Medicine is categorically called Controlled substances by the government. For instance, Schedule H or X in India and schedule II-V in the US are controlled substances.
Please consult the medicine instruction manual on how to use and ensure it is not a controlled substance.In conclusion, self medication is a killer to your health. Consult your doctor for a proper prescription, recommendation, and guidiance.
ReviewsDrugs.com conducted a study on Trimethoprim, and the result of the survey is set out below. It is noteworthy that the product of the survey is based on the perception and impressions of the visitors of the website as well as the views of Trimethoprim consumers. We, as a result of this, advice that you do not base your therapeutic or medical decisions on this result, but rather consult your certified medical experts for their recommendations.
The information was verified by Dr. Arunabha Ray, MD Pharmacology