The effect of the first liver passage For a perorally administered pharmaceutical agent to exert its effects at the site of action, it usually must enter the systemic circulation. To do so, it must pass through the intestinal wall, the liver, and part of the circulatory system. Despite complete absorption in the intestine, the bioavailability … First-Pass Metabolism
Symptoms Gout is an inflammatory disease of the joints that manifests acutely in attacks of severe pain that worsens with pressure, touch, and movement. The joints are swollen with inflammation, and the skin is red and warm. Fever is observed. Gout often begins in the lower extremities and at the metatarsophalangeal joint (podagra). Urat crystals … Gout Causes and Treatment
Products Fexofenadine is commercially available in tablet form (Telfast, Telfastin Allergo, generic). It was approved in many countries in 1997 and has been available without a doctor’s prescription since 2010. Telfastin Allergo 120 for self-medication went on sale in February 2011. Fexofenadine is the successor product to terfenadine (Teldane), which had to be withdrawn from … Fexofenadine
Background That grapefruit juice can cause drug-drug interactions was discovered by chance in a clinical trial in 1989 and confirmed in an experiment by the same research group in 1991 (Bailey et al, 1989, 1991). This showed that simultaneous ingestion of grapefruit juice with the calcium channel blocker felodipine significantly increases the bioavailability of felodipine. … Interactions with Grapefruit Juice
Introduction Breast cancer resistance protein (BCRP or ABCG2) is an efflux transporter that belongs to the ABC superfamily (ATP-binding cassette). It is encoded by the gene first isolated from breast cancer cells in 1998. BCRP consists of 655 amino acids and has a molecular weight of 72 kDa. BCRP mediates resistance to structurally and pharmacologically … BCRP
What are prodrugs? Not all active pharmaceutical ingredients are directly active. Some must first be converted to the active substance by an enzymatic or non-enzymatic conversion step in the body. These are the so-called . The term was introduced by Adrien Albert in 1958. It is estimated that up to 10% of all active ingredients … Prodrugs
Products Probenecid is commercially available in tablet form (Santuril). Santuril has been approved in many countries since 2005. Structure and properties Probenecid (C13H19NO4S, Mr = 285.4 g/mol) is a white crystalline powder that is practically insoluble in water. Effects Probenecid (ATC M04AB01) inhibits tubular reabsorption of uric acid and secretion of organic anions. It thus … Probenecid
Products Lip creams containing aciclovir have been approved in many countries since 1997 (Zovirax Lip Cream, generic). Structure and properties Aciclovir (C8H11N5O3, Mr = 225.2 g/mol) exists as a white crystalline powder that is sparingly soluble in water. It mimics 2′-deoxyguanosine. Effects Aciclovir (ATC D06BB03) is antiviral against herpes simplex viruses. It is a prodrug … Aciclovir Lip Cream
Background The human organism has several mechanisms to metabolize endogenous and foreign substances. One of these mechanisms is glucuronidation, which occurs primarily in the liver. In this process, enzymes from the superfamily of UDP-glucuronosyltransferases (UGT) transfer a molecule of glucuronic acid from UDP-glucuronic acid to the substrate. Using acetaminophen as an example, alcohols, phenols, carboxylic … Meulengracht’s Disease
Products Pramipexole is commercially available in tablet and sustained-release tablet form (Sifrol, Sifrol ER, generics). It has been approved in many countries since 1997; generics were released in 2010 and entered the market in January 2011. Sifrol ER sustained-release tablets were relaunched by the original manufacturer in 2010. Structure and properties Pramipexole (C10H17N3S, Mr = … Pramipexole
