Zolmed/Zolmed Forte

Zolmed/Zolmed Forte

sulfamethoxazole + trimethoprim




Full Prescribing Info
Cotrimoxazole: Sulfamethoxazole, trimethoprim.
Each capsule contains: Sulfamethoxazole 400 mg and Trimethoprim 80 mg.
Each 5 mL (1 teaspoonful) contains: Sulfamethoxazole 200 mg and Trimethoprim 40 mg.
Each 5 mL (1 teaspoonful) contains: Sulfamethoxazole 400 mg and Trimethoprim 80 mg.
Each Tablet contains: Sulfamethoxazole 800 mg and Trimethoprim 160 mg.
Cotrimoxazole is a mixture of the medium-acting sulfonamide, sulfamethaxazole, and the diaminopyrimidine, trimethoprim, in the proportion of 5 parts of sulfamethoxazole to 1 part of trimethoprim. It is used in the infections caused by susceptible bacteria, particularly those of the urinary, respiratory, and gastrointestinal tracts. It is used to treat nocardiosis and is usually the drug of choice for the management of Pneumocystis pneumonia.
Pharmacology: Pharmacodynamics: Mechanism of Action: The antimicrobial activity of the combination of trimethoprim and sulfamethoxazole results from its actions in two steps of the enzymatic pathway for the synthesis of tetrahydrofolic and sulfonamides inhibits the incorporation of PABA into folic acid, and trimethoprim presents the reduction of dihydrofolate to tetrahydrofolate, the latter in the form of folate essential for one carbon transfer reactions. The synergistic interaction between sulfonamide and trimethoprim is predictable from their respective mechanism. There is an equal to the ratio of the concentration of the two agents for synergism, and this is equal to the ratio of the inhibitory concentration of the drugs acting independently. The most effective ratio for the greatest number of the microorganism 20 parts of sulfamethoxazole to one part of trimethoprim. The minimal inhibitory concentration for sulfamethoxazole alone is 3 mcg/mL, while that for trimethoprim is 0.3 mg/mL. When the combination is tested a ratio of 20.1 inhibitory concentrations and 0.1 mcg/mL and 0.85 mcg/mL, respectively the combination is actually bactericidal for one microorganism.
Bacterial Resistance: Sulfamethoxazole is lower than it is to either of the agent alone. Since microorganism that has acquired resistance to one of the components may still be killed by the other. Trimethoprim-resistant microorganisms may arise by mutations. Resistance in gram negative bacteria is often associated with the acquisition of a plasmid that codes for an altered dihydrofolate reductase. Sulfamethoxazole increased only from 0.2% to 1.5% over a period.
Pharmacokinetics: Cotrimoxazole is rapidly ad well absorbed from the gastrointestinal tract and peak plasma concentrations are reached between 1 to 4 hours after an oral dose; effective plasma concentration are maintained for up to 24 hours after an oral therapeutic dose. Steady-state concentrations are reached after dosing for 2 to 3 days. Plasma concentrations of trimethoprim and sulfamethoxazole ae generally around the optimal ratio of 1:20 although they may vary from 1:20 to 1:30 or more.
The ratio of the to drugs is usually much lower in the tissues (often around 1:2 to 1:5) since trimethoprim, the more lipophilic drug penetrates many tissues better than sulfamethoxazole and has much larger volume of distribution. In urine, the ratio may vary from 1:1 to 1:5 depending on the pH. Cotrimoxazole is excreted mainly by the kidneys through both glomerular filtration and tubular secretion; about 505 is excreted in the urine within 24 hours as uchanged drug.
Urinary tract infections, bactericidal, respiratory tract infections, gastro-intestinal infections, infections by Pneumocystis carinii, prophylaxis in neutropenic patients, genital infections and miscellaneous infections.
Dosage/Direction for Use
6-12 years: (5 mL) one teaspoonful three times a day or as prescribed by the physician.
Adult Dosage: 800/160 mg Tablet: One (1) tablet every 12 hours after meals.
400 mg/80 mg capsule: one (1) to two (2) capsule every 12 hours after meals or as prescribed by the physician.
Sodium metabisulfite contains a sulfite that may cause allergic type reactions, including anaphylactic symptoms and life threatening or less severe asthmatic episode in certain susceptible persons.
Special Precautions
Cotrimoxazole should not be given to patients with history of sensitivity to it or to sulphonamide or trimethoprim and to patients with actual or possible folate deficiency, during pregnancy, and in patients receiving trimethoprim.
Use In Pregnancy & Lactation
No adverse effects have been seen in breast-fed infants whose mothers were taking cotrimoxazole, and the last available guidance from the American Academy of Pediatrics considered that it was therefore usually compatible with breast feeding.
Adverse Reactions
Trimethoprim sulfamethoxazole may cause or precipitate megaloblastosis, leukopenia or thrombocytopenia, skin rash, recurrent fever, neutropenia and raised liver enzyme values.
Drug Interactions
For Sulfamethoxazole: The action of sulfonamides may be antagonized by p-aminobenzoic acid and its derivatives, particularly potassium aminobenzoate and the procaine group of local anesthetics.
Sulfamethoxazole and other sulfonamides may potentiate the effects of some drugs, such as oral anticoagulants, methotrexate, and phenytoin; this may be due to displacement of the drug from plasma protein binding sites or to inhibition of metabolism.
For Trimethoprim: Trimethoprim may increase serum concentrations of some drugs, including phenytoin, digoxin, procainamide, rosiglitazone, and repaglinidine, potentiating their effect. This may be due to competitive inhibition of renal excretion, decreased metabolism, or both. It has been suggested that trimethoprim may potentiate the effects of warfarin. Trimethoprim has been reported to reduce the renal excretion and increase blood concentrations of zidovudine, zalcitabine, and lamivudine. Trimethoprim and dapsone increase each other's serum concentrations, whereas rifampicin may decrease trimethoprim concentrations.
Store at a temperature not exceeding 30°C.
MIMS Class
Antibacterial Combinations
ATC Classification
J01EE01 - sulfamethoxazole and trimethoprim ; Belongs to the class of combinations of sulfonamides and trimethoprim, including derivatives. Used in the systemic treatment of infections.
Zolmed cap 400 mg/80 mg x 100's. Zolmed oral susp 200 mg/40 mg/5 mL x 60 mL. Zolmed Forte tab 800 mg/160 mg x 100's. Zolmed Forte oral susp 400 mg/80 mg/5 mL x 60 mL.
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