Sulfadiazine is an antibiotic. Used together with pyrimethamine, a dihydrofolate reductase inhibitor, it is the treatment of choice for toxoplasmosis, which is caused by a protozoan parasite. It is a second-line treatment for otitis media, prophylaxis of rheumatic fever, chancroid, chlamydia, and infections by Haemophilus influenzae. It is also used as adjunct therapy for chloroquine-resistant malaria and several forms of bacterial meningitis. It is taken by mouth. Sulfadiazine is available in multiple generic tablets of 500 mg. For urinary tract infections, the usual dose is 4 to 6 grams daily in 3 to 6 divided doses.Common side effects include nausea, diarrhea, headache, fever, rash, depression, and pancreatitis. It should not be used in people who have severe liver problems, kidney problems, or porphyria. If used during pregnancy, it may increase the risk of kernicterus in the baby. While the company that makes it does not recommend use during breastfeeding, use is believed to be safe if the baby is otherwise healthy. It is in the sulfonamide class of medications.Sulfadiazine was approved for medical use in the United States in 1941. It is on the World Health Organizations List of Essential Medicines. Sulfadiazine is available as a generic medication. Medical uses
It eliminates bacteria that cause infections by stopping the production of folate inside the bacterial cell, and is commonly used to treat urinary tract infections and burns. In combination, sulfadiazine and pyrimethamine can be used to treat toxoplasmosis, the disease caused by Toxoplasma gondii. Mechanism of action
Sulfadiazine works by inhibiting the enzyme dihydropteroate synthetase.
Some eyes have up to 28,000 such sensors arranged hexagonally, which can give a full 360° field of vision. Compound eyes are very sensitive to motion. Some arthropods, including many Strepsiptera, have compound eyes of only a few facets, each with a retina capable of creating an image. With each eye producing a different image, a fused, high-resolution image is produced in the brain. Possessing detailed hyperspectral colour vision, the Mantis shrimp has the worlds most complex colour vision system. Trilobites, now extinct, had unique compound eyes. Clear calcite crystals formed the lenses of their eyes. They differ in this from most other arthropods, which have soft eyes. The number of lenses in such an eye varied widely; some trilobites had only one while others had thousands of lenses per eye. In contrast to compound eyes, simple eyes have a single lens. Jumping spiders have one pair of large simple eyes with a narrow field of view, augmented by an array of smaller eyes for peripheral vision. Some insect larvae, like caterpillars, have a type of simple eye (stemmata) which usually provides only a rough image, but (as in sawfly larvae) can possess resolving powers of 4 degrees of arc, be polarization-sensitive, and capable of increasing its absolute sensitivity at night by a factor of 1,000 or more. Ocelli, some of the simplest eyes, are found in animals such as some of the snails. They have photosensitive cells but no lens or other means of projecting an image onto those cells.