Levamisole is used as anthelmintic agent to get rid of the intestinal worms. It is (S)-(-)-enantiomer of tetramisole. This drug is used in veterinary to treat hookworm infections. Levamisole also finds therapeutic application in the treatment of colon cancer when given in conjunction with fluorouracil. Chirality and biological activity Tetramisole carries one chiral stereogenic …
Beta blockers, also spelled β-blockers, used as antihypertensive agents (lowering blood pressure), represent a class of chiral drugs that are marketed as racemates since the distomer exhibits no undesirable adverse effects. Three most important β-blockers viz. propranolol, atenolol, and metoprolol are marketed as racemic mixture. Chirality and biological activity β-blockers are aryloxy propanolamines with one stereogenic …
Levodopa, L-Dopa, belong to a class of medications called dopamine agonists. L-Dopa is used to increase dopamine concentrations in the treatment of Parkinson’s disease. Most commonly, clinicians use levodopa as a dopamine replacement agent for the treatment of Parkinson disease. L-dopa is the precursor to dopamine and crosses the blood-brain barrier to increase dopamine neurotransmission. Chirality and Biological activity L-dopa, …
(±)-Terodiline, the antianginal agent, perhaps represents the best authenticated example of a drug that had to be withdrawn from the world market as consequence of proven stereospecific toxicity. Terodiline has a close similarity to prenylamine from a structural and pharmacological view point. It was firs marketed as an antianginal agent but it exhibited urinary retention …
(±)-Prenylamine, an antianginal agent, was introduced in the market since early 1960. Reports associating Prenylamine with prolongation of the QT interval, ventricular tachycardia, and ventricular fibrillation started to appear. Some of these events had a fatal outcome and the drug was withdrawn from the market world-wide in 1988. Chirality and drug withdrawals Prenylamine is chemically …
Dilevalol is the (R,R)-diastereoisomer of labetalol. Labetalol has been in clinical use since 1977 for the treatment of hypertension. Labetalol is an adrenergic antagonist used to treat high blood pressure. It has a role as an antihypertensive agent, a sympatholytic agent, an alpha-adrenergic antagonist and a beta-adrenergic antagonist. Chirality and drug withdrawals Labetalol has two stereogenic …
Thalidomide was a racemic therapeutic and prescribed to pregnant women to control nausea and vomiting. The drug was withdrawn from world market when it became evident that the use in pregnancy causes phocomelia (clinical conditions where babies are born with deformed hand and limbs). Later in late 1970s, the thalidomide enantiomers were separated and enantioselective …
Indacrinone is an orally active, indanone-based loop diuretic patented by American pharmaceutical company Merck and Co as mixture of two enantiomers. In healthy volunteers, the racemic mixture of indacrinone exhibited greater natriuretic potency than furosemide, with a slower onset and longer duration of action. Furthermore, single doses of indacrinone decreased serum uric acid concentrations and …
Levocetirizine, is chiral switch cetirizine, employed for allergies. It is a third generation, non-sedating, selective histamine H1 receptor antagonist, with antihistamine, anti-inflammatory and potential anti-angiogenic activities. Levocetirizine is used to relieve the symptoms of hay fever and hives of the skin. It is an antihistamine that works by preventing the effects of a substance called histamine, which is …
Citalopram belongs to a class of antidepressant agents known as selective serotonin-reuptake inhibitors (SSRIs). It is indicated for the treatment of depression. Chirality and biological activity Citalopram has one stereocenter, to which a 4-fluoro phenyl group and an N, N-dimethyl-3-aminopropyl group are linked. As a consequence the molecule exists as an enantiomeric pair, the S-(+)-citalopram and …