Zidovudine (AZT) or tenofovir (TDF) are recommended as less toxic and equally effective alternatives." Mechanism of action
Stavudine is a nucleoside analog of thymidine. It is phosphorylated by cellular kinases into an active triphosphate. Stavudine triphosphate inhibits HIVs reverse transcriptase by competing with the natural substrate, thymidine triphosphate. Reverse transcriptase is the enzyme the virus uses to make a DNA copy of its RNA in order to insert its genetic material into the hosts DNA. Upon incorporation into the DNA strand, stavudine triphosphate causes termination of DNA replication. Pharmacokinetics
Absorption: Stavudine has rapid absorption and good oral bioavailability  (F = 0.86).Distribution: Stavudine does not bind to proteins in the blood.Metabolism: The clearance of stavudine is affected minimally by hepatic metabolism. Oxidation and glucuronidation produce minor metabolites.Elimination: Stavudine is mostly eliminated in the urine and mostly in its unchanged form. Drug interactions
Simultaneous use of zidovudine is not recommended, as it can inhibit the intracellular phosphorylation of stavudine. Other anti-HIV drugs do not possess this property. Stavudine is not protein-bound nor does it inhibit the major cytochrome P450 isoforms. Thus, significant drug interactions with drugs metabolized through these pathways or drugs that are protein-bound are unlikely. History
Stavudine was first created by Jerome Horwitz in the 1960s and was originally named D4T. When the AIDS epidemic occurred in the 1980s, William Prusoff and Dr. Tai-Shun Lin discovered the anti-HIV properties of Stavudine.
Pharmacology
Ropinirole acts as a D2, D3, and D4 dopamine receptor agonist with highest affinity for D3, which are mostly found in the limbic areas. It is weakly active at the 5-HT2, and α2 receptors and is said to have virtually no affinity for the 5-HT1, GABA, mAChRs, α1, and β-adrenoreceptors.Ropinirole is metabolized primarily by cytochrome P450 CYP1A2 to form two metabolites; SK&F-104557 and SK&F-89124, both of which are renally excreted, and at doses higher than clinical, is also metabolized by CYP3A4. At doses greater than 24 mg, CYP2D6 may be inhibited, although this has been tested only in vitro. Society and culture
It is manufactured by GlaxoSmithKline (GSK), Mylan Pharmaceuticals, Cipla, Dr. Reddys Laboratories and Sun Pharmaceutical. The discovery of the drugs utility in RLS has been used as an example of successful drug repurposing. Lawsuits
In November 2012, GlaxoSmithKline was ordered by a Rennes appeals court to pay Frenchman Didier Jambart 197,000 euros ($255,824); Jambart had taken ropinirole from 2003 to 2010 and exhibited risky hypersexual behavior and gambled excessively until stopping the medication. References
External links
"Ropinirole". Drug Information Portal. U.S. National Library of Medicine. "Ropinirole hydrochloride". Drug Information Portal. U.S. National Library of Medicine.