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- What is sulfamethoxazole, and how does it work (mechanism of action)?
- What are the side effects of sulfamethoxazole?
- What is the dosage for sulfamethoxazole?
- Which drugs or supplements interact with sulfamethoxazole?
- Is sulfamethoxazole safe to take if I'm pregnant or breastfeeding?
- What else should I know about sulfamethoxazole?
What is sulfamethoxazole, and how does it work (mechanism of action)?
Sulfamethoxazole is an anti- bacterial sulfonamide. It prevents the formation of dihydrofolic acid, a compound that bacteria must be able to make in order to survive. Although it was once a very useful antibiotic, it is almost obsolete as a single agent today due to the development of bacterial resistance to its effects. Sulfamethoxazole is now used primarily in combination with trimethoprim, a combination product known as Bactrim or Septra.
Sulfamethoxazole may be used to treat acute, recurrent or chronic urinary tract infections (primarily pyelonephritis, pyelitis and cystitis) due to susceptible organisms (usually E. coli, Klebsiella-Enterobacter, staphylococcus, Proteus mirabilis and, less frequently, Proteus vulgaris) in the absence of obstructive uropathy or foreign bodies.
Meningococcal meningitis prophylaxis when sulfonamide-sensitive group A strains are known to prevail in family groups or larger closed populations. (The prophylactic usefulness of sulfonamides when group B or C infections are prevalent has not been proven and in closed population groups may be harmful.)
Trachoma. Inclusion conjunctivitis. Nocardiosis. Chancroid. Toxoplasmosis as adjunctive therapy with pyrimethamine. Malaria due to chloroquine-resistant strains of Plasmodium falciparum, when used as adjunctive therapy.
Sulfamethoxazole was approved by the FDA in 1961. According to the FDA database, all brand and generic formulations of sulfamethoxazole have been discontinued.
Is sulfamethoxazole available as a generic drug?
Do I need a prescription for sulfamethoxazole?
What are the side effects of sulfamethoxazole?
: Common side effects of sulfamethoxazole are:
Sulfamethoxazole should be stopped at the first appearance of a skin rash since the rash may become severe. Serious rashes include Stevens-Johnson syndrome (aching joints and muscles; redness, blistering, and peeling of the skin); toxic epidermal necrolysis (difficulty in swallowing; peeling, redness, loosening, and blistering of the skin). Sulfamethoxazole therapy also can cause extensive sunburn, following exposure to sunlight. Patients receiving sulfamethoxazole should avoid excessive exposure to sunlight and should wear sunscreen.
Other important rare side effects include:
Sulfamethoxazole may form crystals in the urine which may damage the kidney and cause bleeding into the urine. It is important to drink additional liquids during sulfonamide therapy to prevent these side effects.
What is the dosage for sulfamethoxazole?
Sulfamethoxazole usually is taken two or three times daily, with or without meals. It should be taken with 6 to 8 ounces of liquid to prevent crystals from forming in the urine. Persons with advanced kidney diseases may require lower doses.
Which drugs or supplements interact with sulfamethoxazole?
Sulfamethoxazole can enhance the blood-thinning effects of warfarin (Coumadin), possibly leading to bleeding. Sulfonamides such as sulfamethoxazole can increase the metabolism (break-down and elimination) of cyclosporine (causing loss of effectiveness of cyclosporine), and can add to the kidney damage caused by cyclosporine. All sulfonamides can crystallize in urine when the urine is acidic. Since methenamine (Hiprex, Urex, Mandelamine) causes an acidic urine, it should not be used with sulfonamides.
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Is sulfamethoxazole safe to take if I'm pregnant or breastfeeding?
The effects of the sulfonamide class of antibiotics on the fetus have not been adequately studied. Therefore, physicians may use them if the benefits are deemed to outweigh potential risks. On the other hand, use of sulfonamides near term (that is, near the ninth month of pregnancy) may cause bilirubin to be displaced from proteins in the infant's blood. Displacement of bilirubin can lead to a dangerous condition called kernicterus in which the bilirubin damages the brain. For this reason, sulfonamides should not be used near term birth.
What else should I know about sulfamethoxazole?
What preparations of sulfamethoxazole are available?
Tablets: 500 mg and 1 gm.
How should I keep sulfamethoxazole stored?
The tablets should be kept at room temperature, 15 C - 30 C (59 F - 86 F).
Sulfamethoxazole (Gantanol, Gantanol DS) is an antibiotic prescribed for the treatment of malaria, pinkeye due to chlamydia, toxoplasmosis, and urinary tract infections. According to the FDA database, all brand and generic formulations of sulfamethoxazole have been discontinued. Side effects, drug interactions, warnings and precautions, and patient safety information should be reviewed prior to taking any medication.
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Malaria is a disease that is spread by the bite of an infected Anopheles mosquito. Malaria symptoms include fever, chills, nausea, vomiting, and body aches. Treatment involves supportive care and antibiotics.
Pinkeye, also called conjunctivitis, is redness or irritation of the conjunctivae, the membranes on the inner part of the eyelids and the membranes covering the whites of the eyes. These membranes react to a wide range of bacteria, viruses, allergy-provoking agents, irritants, and toxic agents.
Sexually Transmitted Diseases in Women (STDs)
Sexually transmitted diseases (STDs) are among the most common infectious diseases in the United States. STDs can be spread through any type of sexual activity involving the sex organs, the anus or mouth, or through contact with blood during sexual activity. Examples of STDs include, chancroid, chlamydia, gonorrhea, granuloma inguinale, lymphogranuloma venereum, syphilis, genital herpes, genital warts, trichomoniasis, pubic lice (crabs), and scabies. Treatment is generally with antibiotics; however, some STDs that go untreated can lead to death.
Urinary Tract Infection (UTI)
A urinary tract infection (UTI) is an infection of the bladder, kidneys, ureters, or urethra. E. coli, a type of bacteria that lives in the bowel and near the anus, causes most UTIs. UTI symptoms include pain, abdominal pain, mild fever, urinary urgency and frequency. Treatment involves a course of antibiotics.
Whooping Cough (Pertussis)
Whooping cough (pertussis) is highly contagious respiratory infection that is caused by the bacteria Bordetella pertussis. There are an estimated 300,000 plus deaths annually from whooping cough (pertussis). Whooping cough commonly affects infants and young children but can be prevented with immunization with the vaccine. First stage whooping cough symptoms are a runny nose, sneezing, low-grade fever, a mild cough with the cough gradually becoming more severe. After one to two weeks, the second stage of whooping cough begins.
Chlamydia in Women
Chlamydia is the most common sexually transmitted disease in the U.S. Signs and symptoms of chlamydia, a bacterial infection, include vaginal discharge, abdominal pain, burning with urination, blood in the urine, and feelings of urinary urgency and frequency. Untreated chlamydia can cause pelvic inflammatory disease (PID), increased risk of ectopic pregnancy, and infertility. Chlamydia is diagnosed with a culture or by identification of the genetic material of the bacteria. Treatment of chlamydia consists of a course of antibiotics.
Toxoplasmosis (toxo) is a parasitic infection that causes flu-like symptoms, swollen lymph nodes, and muscle aches and pains that may last from a few days to several weeks. Toxoplasmosis can be contracted by touching the hands to the mouth after gardening, cleaning a cat's litter box, or anything that came into contact with cat feces. Toxoplasmosis can also be contracted by eating raw or partly cooked meat, especially pork or lamb, or touching the hands to the mouth after contact with raw or undercooked meat.
STDs in Men
Sexually transmitted diseases (STDs) are infections transmitted during sexual contact. They may be caused by viruses, bacteria, or parasites. STDs in men cause no symptoms or symptoms like genital burning, itching, sores, rashes, or discharge. Common infections that are sexually transmitted in men include gonorrhea, chlamydia, syphilis, hepatitis C and B, genital warts, human papillomavirus (HPV), and genital herpes. Some STDs in men are treatable while others are not. STDs are diagnosed with tests that identify proteins or genetic material of the organisms causing the infection. The prognosis of an STD depends on whether the infection is treatable or not. Use of latex condoms can help reduce the risk of contracting an STD but it does not eliminate the risk entirely.
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