Oxytetracycline

Chloramphenicol is a bacteriostatic antimicrobial originally derived from the bacterium Streptomyces venezuelae, isolated by David Gottlieb, and introduced into clinical practice in 1949.

It was the first antibiotic to be manufactured synthetically on a large scale. Chloramphenicol is effective against a wide variety of microorganisms; it is still very widely used in low income countries because it is exceedingly cheap, but has fallen out of favour in the West due to a very rare but very serious side effect: aplastic anemia.

The usual dose is 50 mg/kg/day in four divided doses: the usual dose in an adult male is therefore around 750 mg four times daily; this dose is doubled in severe illness. Half the dose is used in premature babies or neonates, because they do not metabolise the drug as effectively.

Chloramphenicol is available as 250 mg capsules or as a liquid (125 mg/5 ml). In some countries, chloramphenicol is sold as chloramphenicol palmitate ester. Chloramphenicol palmitate ester is inactive, and is hydrolysed to active chloramphenicol in the small intestine. There is no difference in bioavailability between chloramphenicol and chloramphenicol palmitate.

The intravenous (IV) preparation of chloramphenicol is the succinate ester, because pure chloramphenicol does not dissolve in water. This creates a problem: chloramphenicol succinate ester is an inactive prodrug and must first be hydrolysed to chloramphenicol; the hydrolysis process is incomplete and 30% of the dose is lost unchanged in the urine, therefore serum concentrations of chloramphenicol are only 70% of those achieved when chloramphenicol is given orally.For this reason, the chloramphenicol dose needs to be increased to 75 mg/kg/day when administered IV in order to achieve levels equivalent to the oral dose.The oral route is therefore preferred to the intravenous route.

Acenocoumarol is an anticoagulant that functions as a vitamin K antagonist (like warfarin). It is a derivative of coumarin and is marketed under the brand names Sintrom and Sinthrome.

Nicoumalone is an anticoagulant medicine, used to prevent blood clots which can be damaging to the body. The formation of blood clots involves a complicated interaction of substances. There are substances in the blood known as clotting factors, and factors II, VII, IX and X must be present for clotting to occur. Nicoumalone prevents the normal formation of factors II, VII, IX and X, and this prevents blood clots from forming. Nicoumalone is used to prevent blood clots in instances where clotting would be damaging eg:- -Deep vein thrombosis. In areas where blood flow is slow, such as the veins in the leg, blood clots more easily. If a clot forms here, it can travel in the bloodstream to the lungs where it causes damage (pulmonary embolism). -In certain heart conditions where the heart is pumping erratically eg. atrial fibrillation or rheumatic heart disease, clots can form in the heart. These can cause a heart attack or detach and travel around the blood vessels (embolus). Clots may travel to the brain, causing a stroke. -When an artificial heart valve has been inserted clots can form on

Fluticasone is a potent synthetic corticosteroid often prescribed as treatment for asthma and allergic rhinitis.

The related fluticasone propionate is marketed with the brand names Flixotide (UK) for asthma and Flixonase (UK) for allergic rhinitis by Allen & Hanburys. In the US, it is marketed for asthma as Flovent, and allergic rhinitis as Flonase, by GlaxoSmithKline. GlaxoSmithKline also markets a combination of fluticasone and salmeterol as Advair (US) or Seretide (UK).

The related fluticasone furoate is marketed by GlaxoSmithKline as Veramyst (US) for the treatment of allergic rhinitis.