The concentration of azithromycin in the tissues can be over 50 times higher than in plasma due to ion trapping and its high lipid solubility. Azithromycins half-life allows a large single dose to be administered and yet maintain bacteriostatic levels in the infected tissue for several days.Following a single dose of 500 mg, the apparent terminal elimination half-life of azithromycin is 68 hours. Biliary excretion of azithromycin, predominantly unchanged, is a major route of elimination. Over the course of a week, about 6% of the administered dose appears as an unchanged drug in urine. History
A team of researchers at the pharmaceutical company Pliva in Zagreb, Croatia,—Gabrijela Kobrehel, Gorjana Radobolja-Lazarevski, and Zrinka Tamburašev, led by Slobodan Đokić—discovered azithromycin in 1980. The company Pliva patented it in 1981. In 1986, Pliva and Pfizer signed a licensing agreement, which gave Pfizer exclusive rights for the sale of azithromycin in Western Europe and the United States. Pliva put its azithromycin on the market in Central and Eastern Europe under the brand name Sumamed in 1988. Pfizer launched azithromycin under Plivas license in other markets under the brand name Zithromax in 1991. Patent protection ended in 2005. Society and culture
Available forms
Azithromycin is available as a generic medication. Azithromycin is commonly administered in film-coated tablet, capsule, oral suspension, intravenous injection, granules for suspension in sachet, and ophthalmic solution. Usage
In 2010, azithromycin was the most prescribed antibiotic for outpatients in the US, whereas in Sweden, where outpatient antibiotic use is a third as prevalent, macrolides are only on 3% of prescriptions.
Pyrantel is a medication used to treat a number of parasitic worm infections. This includes ascariasis, hookworm infections, enterobiasis (pinworm infection), trichostrongyliasis, and trichinellosis. It is taken by mouth.Side effects include nausea, headache, dizziness, trouble sleeping, and rash. A lower dose should be used in people with liver disease. While it does not appear to be harmful during pregnancy, it has not been studied for this use. It is unclear if it is safe for use during breastfeeding. It is in the antihelmintic family of medications. It works by paralyzing worms.Pyrantel was initially described in 1965. It is on the World Health Organizations List of Essential Medicines. Pyrantel is available as a generic medication. It costs less than US$25 per course of treatment in the United States. It may also be used to treat worms in a number of other animals. Pregnancy and breastfeeding
Pyrantel pamoate is considered a pregnancy category C drug for use during pregnancy for humans, but is in category A for canines and felines. Pyrantel is considered safe to use in nursing animals. Mechanism of action
Pyrantel pamoate acts as a depolarizing neuromuscular blocking agent, thereby causing sudden contraction, followed by paralysis, of the helminths. This has the result of causing the worm to "lose its grip" on the intestinal wall and be passed out of the system by natural process. Since Pyrantel is poorly absorbed by the hosts intestine, the host is unaffected by the small dosage of medication used.