Indications
Sulfamethoxazole/trimethoprim is used for treating infections due to susceptible bacteria:
- Genitourinary infections: Urinary tract infections, prostatitis
- Chronic and recurrent urinary tract infections in adult women.
- Respiratory tract infections: Acute exacerbations of chronic bronchitis, acute pneumonia or acute otitis media in children, acute sinusitis in adults.
- Gastrointestinal infections: Shigellosis, typhoid fever.
Dosage and administration
- Genitourinary infections
- Adults: 2 sachets, twice daily (taking every 12 hours) for 10 days.
- Or single dose of 4 sachets, but minimum term therapy of 3 or 7 days duration has been shown to be more effective.
- Children: 40mg sulfamethoxazole + 8 mg trimethoprim per kg body weight, 2 times daily (taking every 12 hours) for 10 days.
- Chronic and recurrent urinary tract infections in adult women:
½ sachet daily or 1 – 2 sachets once, 1 or 2 times every week.
- Respiratory tract infections:
- Acute exacerbations of chronic bronchitis:
Adults: 2 – 3 sachets, twice daily for 10 days.
- Acute otitis media or acute pneumonia in children: 40mg sulfamethoxazole + 8 mg trimethoprim per kg body weight within 24 hours, in 2divided doses for 5 – 10 days.
- Gastrointestinal infections
- Shigellosis:
- Adults: 2 sachets, twice daily (taking every 12 hours) for 5 days.
- Children: 40mg sulfamethoxazole + 8 mg trimethoprim per kg body weight within 24 hours, in 2divided doses for 5 days.
Contraindications
- Hypersensitivity to any component of this medicine.
- Severe renal insufficiency when Supertrim plasma level cannot be monitored.
- Known megaloblastic anemia due to folic acid deficiency.
- Pregnant women and nursing mothers.
- Children under 2 months.
Precautions
- Impaired renal or hepatic function.
- Possible folic acid deficiency (e.g., the elderly or high dose use of supertrim for long term).
- Trimethoprim and sulfamethoxazole may cause hemolytic anemia in patient with G-6PD deficiency.
Interactions
- Co-administration of Supertrim® and diuretics, especially thiazides, may increase the risk of thrombocytopenia in elderly patients.
- Sulfonamides may inhibit plasma protein binding and renal excretion of methotrexate and thus reduce the elimination, increase the effects of methotrexate.
- Concurrent use of Supertrim® and pyrimethamine (25 mg per week) increases the risk of megaloblastic anemia.
- Supertrim® inhibits the phenytoin metabolism in the liver which may result in the possible excessive phenytoin effect of phenytoin.
- Supertrim® may prolong prothrombin time in patients who are receiving warfarin.
Pregnancy and Lactation: Supertrim® should not be used during pregnancy and lactation.
Effects on ability to drive and use machines Supertrim® has no known influence on the ability to drive and use machines.
Undesirable effects
- The most common undesirable effects occur in the gastrointestinal tract (5%) and skin reactions occur in at least 2% of patients taking Supertrim® such as rash, erythema multiforme. The ADR is usually mild, but Stevens-Johnson syndrome and toxic epidermal necrolysis (Lyell’s syndrome) may rarely occur leading to death.
- The drug is not recommended for patients with known megaloblastic anemia or patients with severe liver disease, toxic hepatitis.
- Common: ADR >1/100
- Body as a whole: Fever.
- Gastrointestinal: Nausea, vomiting, diarrhea, glossitis.
- Skin: Pruritus, rash.
- Uncommon: 1/1000 < ADR < 1/100
- Blood: Eosinophilia, leukopenia, neutropenia, purpura.
- Skin: Urticaria.
- Rare: ADR< 1/1000
- Body as a whole: Anaphylactic reaction, serum sickness-like syndrome.
- Blood: Megaloblastic anemia, hemolytic anemia, thrombocytopenia, agranulocytosis and reductionin total blood cells.
- Liver: Jaundice, cholestatic liver, liver necrosis.
- Metabolism: Hyperkalemia,
- Psychiatry: Hallucinations.
- Genitourinary: Renal failure, interstitial nephritis, crystalluria.
- Ears: Tinnitus.
- Guidelines for ADR manangement
- ADR due to folic acid deficiency can be avoided when 5 – 10 mg doses of folic acid were administered daily without reducing the antibacterial effect. It should be noted that deficiency of folic acid in the body are not fully reflected through serum concentrations of folic acid.
- The risk of hyperkalemia also occurs at normal doses and should be considered; especially, when Supertrim® is used concomitantly with other agents causing hyperkalemia or in case of kidney failure.
- Patients should be advised to drink enough water to prevent Supertrim from urinarystone crystallization. Patients should avoid prolonged exposure to the sun to prevent photosensitivity reactions.
Inform your physician about unwanted effects encountered when using the drug.
Pharmacodynamic properties
- Supertrim® is the combination of sulfamethoxazole and trimethoprim.
- Sulfamethoxazole, a sulfonamide, competitively inhibits folic acid synthesis in microorganisms.
- Trimethoprim is a pyrimidine derivative, specifically inhibits bacterial dihydrofolate reductase.
- Trimethoprim and sulfamethoxazole combination inhibits two consecutive steps of folic acid metabolism, thereby effectively inhibits the synthesis of purine, thymine and finally bacterial DNA. This consecutive inhibition results in bactericidal effect. This synergistic mechanism fights against the development of drug-resistant bacteria and the effectiveness is maintained even if the bacteria are resistant to either trimethoprim or sulfamethoxazole alone.
- The following microorganisms are usually sensitive to Supertrim: Escherichia coli, Klebsiella sp., Enterobacter sp., Morganella morganii, Proteus mirabilis, indole-positive Proteus, including vulgaris, H. influenzae (including ampicillin-resistant strains), S. pneumoniae, Shigella flexneri and Shigella sonnei, Pneumocystis carinii.
- Supertrim® has some effects against Plasmodium falciparum and Toxoplasma gondii.
Pharmacokinetic properties
- Supertrim® is absorbed rapidly from gastrointestinal tract.
- The medicine is distributed throughout body tissues and fluids, including kidney, liver, lung, bronchial secretion, sputum, saliva, intraocular fluid, prostate and vagina.
- Sulfamethoxazole and trimethoprim are excreted primarily by the kidneys through both glomerular filtration and tubular secretion. Small amounts are excreted in the bile.
Overdose and Management
- Signs and symptoms of overdose include anorexia, nausea, vomiting, headache, unconsciousness. Hematopoietic disorders and jaundice are late manifestation of overdose. Myelosuppression.
- Management: Induce vomiting, gastric lavage. Urine is acidified to increase the excretion of trimethoprim. If there are signs of myelosuppression, 5-15 mg of leucovorin (folinic acid) should be used daily until hematopoietic is recovered.
KEEP OUT OF REACH OF CHILDREN
READ CAREFULLY THE INSTRUCTIONS BEFORE USE
FOR FURTHER INFORMATION, CONSULT YOUR PHYSICIAN
USE ONLY UNDER A PHYSICIAN’S PRESCRIPTION
Storage: Protect from humidity and light, below 300C.
Shelf life: 36 months from the manufacturing date.
Do not use after the expiry date print on the label.
