Product Information
Registration Status: ActiveMORTIN-DS TABLET is approved to be sold in Singapore with effective from 1998-10-10. It is marketed by NAINA MOHAMED & SONS PTE LTD, with the registration number of SIN10250P.
This product contains Sulfamethoxazole 800mg, and Trimethoprim 160mg in the form of TABLET. It is approved for ORAL use.
This product is manufactured by MICRO LABS LTD in INDIA.
It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.
Description
A bacteriostatic antibacterial agent that interferes with folic acid synthesis in susceptible bacteria. Its broad spectrum of activity has been limited by the development of resistance. (From Martindale, The Extra Pharmacopoeia, 30th ed, p208)
Indication
For the treatment bacterial infections causing bronchitis, prostatitis and urinary tract infections.
Mechanism of Action
Sulfonamides inhibit the enzymatic conversion of pteridine and p-aminobenzoic acid (PABA) to dihydropteroic acid by competing with PABA for binding to dihydrofolate synthetase, an intermediate of tetrahydrofolic acid (THF) synthesis. THF is required for the synthesis of purines and dTMP and inhibition of its synthesis inhibits bacterial growth. Pyrimethamine and trimethoprim inhibit dihydrofolate reductase, another step in THF synthesis, and therefore act synergistically with the sulfonamides.
Pharmacokinetics
- Absorption
- Rapidly absorbed following oral administration. Also well-absorbed topically.
- Distribution
- Metabolism
- Hepatic. The metabolism of sulfamethoxazole occurs predominately by N4-acetylation, although the glucuronide conjugate has been identified.
- Elimination
Toxicity
Sulfamethoxazole may cause nausea, vomiting, diarrhea and hypersensitivity reactions. Hematologic effects such as anemia, agranulocytosis, thrombocytopenia and hemolytic anemia in patients with glucose-6-phosphate dehydrogenase deficiency may also occur. Sulfamethoxazole may displace bilirubin from albumin binding sites causing jaundice or kernicterus in newborns.
Active Ingredient/Synonyms
3-(p-Aminophenylsulfonamido)-5-methylisoxazole | 3-Sulfanilamido-5-methylisoxazole | 4-Amino-N-(5-methyl-3-isoxazolyl)benzenesulfonamide | Gantanol (tn) | SMX | Sulfamethoxazole | Sulfamethoxazole |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.
Description
A pyrimidine inhibitor of dihydrofolate reductase, it is an antibacterial related to pyrimethamine. The interference with folic acid metabolism may cause a depression of hematopoiesis. It is potentiated by sulfonamides and the trimethoprim-sulfamethoxazole combination is the form most often used. It is sometimes used alone as an antimalarial. Trimethoprim resistance has been reported. [PubChem]
Indication
For the treatment of urinary tract infections, uncomplicated pyelonephritis (with sulfamethoxazole) and mild acute prostatitis. May be used as pericoital (with sulfamethoxazole) or continuous prophylaxis in females with recurrent cystitis. May be used as an alternative to treat asymptomatic bacteriuria during pregnancy (only before the last 6 weeks of pregnancy). Other uses include: alternative agent in respiratory tract infections (otitis, sinusitus, bronchitis and pneumonia), treatment of Pneumocystis jirovecii pneumonia (acute or prophylaxis), Nocardia infections, and traveller's diarrhea.
Mechanism of Action
Trimethoprim binds to dihydrofolate reductase and inhibits the reduction of dihydrofolic acid (DHF) to tetrahydrofolic acid (THF). THF is an essential precursor in the thymidine synthesis pathway and interference with this pathway inhibits bacterial DNA synthesis. Trimethoprim's affinity for bacterial dihydrofolate reductase is several thousand times greater than its affinity for human dihydrofolate reductase. Sulfamethoxazole inhibits dihydrofolate synthetase (aka dihydropteroate synthetase), an enzyme involved further upstream in the same pathway. Trimethoprim and sulfamethoxazole are commonly used in combination due to their synergistic effects. This drug combination also reduces the development of resistance that is seen when either drug is used alone.
Pharmacokinetics
- Absorption
- Readily and almost completely absorbed in the GI tract with peak serum concentrations attained 1-4 hours after oral administration. Widely distributed to tissues and fluids including kidney, lung, seminal fluid, aqueous humour, middle ear fluid, sputum, vaginal secretions, bile, bone and CSF.
- Distribution
- Metabolism
- Hepatic metabolism to oxide and hydroxylated metabolites.
- Elimination
Toxicity
LD50=4850 (orally in mice)
Active Ingredient/Synonyms
2,4-Diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine | 5-[(3,4,5-Trimethoxyphenyl)methyl]-2,4-pyrimidinediamine | Trimethoprim | Triméthoprime | Trimethoprimum | Trimetoprima | Trimethoprim |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.