Angiotensin Ii Antagonist: From 1 Different Sources
any one of a class of drugs that block the action of the hormone *angiotensin II, which constricts blood vessels; they are therefore useful in treating *hypertension. These drugs include candesartan, irbesartan, losartan, telmisartan, and valsartan. Side-effects are usually mild.
A substance formed in tissues or blood vessels when there needs to be local or even massive vasoconstriction. The primary precursor is renin, made by the kidneys, and elevated when the blood seems dehydrated or low in volume; the next substance needed for this reaction is a liver protein, angiotensinogen; when both are present in the blood, local factors can then form this pressor substance. Excess production is often implicated in high blood pressure.... angiotensin
The ENZYME that converts angiotensin I to angiotensin II (see ANGIOTENSIN) is called angiotensin-converting enzyme. Angiotensin II controls the blood pressure and is the most potent endogenous pressor substance produced in the body; angiotensin I has no such pressor activity. Inhibition of the enzyme that converts angiotensin I to angiotensin II will thus have marked effects on lowering the blood pressure, and ACE inhibitors have a valuable role in treating heart failure when thiazides and beta blockers cannot be used or fail to work, especially after myocardial infarction (see HEART, DISEASES OF). Captopril was the ?rst ACE inhibitor to be synthesised: it reduces peripheral resistance by causing arteriolar dilatation and thus lowers blood pressure. Other drugs such as enalapril, lisinopril, cilazapril, quinapril and ramipril have since been developed. Some kidney disorders increase the production of angiotensin II and so cause HYPERTENSION.... angiotensin-convertingenzyme (ace) inhibitors
These are drugs that block the action of HISTAMINE at the H2 receptor (which mediates the gastric and some of the cardiovascular effects of histamine). By reducing the production of acid by the stomach, these drugs – chie?y cimetidine, ranitidine, famotidine and nizatidine – are valuable in the treatment of peptic ulcers (healing when used in high dose; preventing relapse when used as maintenance therapy in reduced dose), re?ux oesophagitis (see OESOPHAGUS, DISEASES OF), and the ZOLLINGERELLISON SYNDROME. These drugs are now being supplanted by PROTON-PUMP INHIBITORS and HELICOBACTER PYLORI eradication therapy. (See also DUODENAL ULCER.)... h2 receptor antagonists
A substance that converts angiotensin I to its active form, angiotensin. Drugs that reduce the action of this enzyme are known as ACE inhibitor drugs and are used in the treatment of hypertension and heart failure.... angiotensin converting enzyme
A group of drugs used in the treatment of hypertension (high blood pressure). They have a similar action to ACE inhibitors but do not cause a dry cough. Examples are losartan and valsartan.... angiotensin ii antagonists
See H-receptor antagonists.... histamine-receptor antagonists
A drug that blocks the action of a hormone.... hormone antagonist
A group of drugs used to treat the nausea and vomiting caused by radiotherapy and anticancer drugs. They are also used to control nausea and vomiting following surgery. Common serotonin antagonists include granisetron and ondansetron.... serotonin antagonists
one of a class of drugs that prevent the action of *leukotrienes by blocking their receptors on cell membranes, such as those in the airways. These drugs are used in the management of asthma for their effects in relaxing the smooth muscle of the airways and in reducing inflammation in the bronchial linings. Examples are montelukast and zafirlukast; side-effects may include headache and abdominal pain or gastrointestinal upsets.... leukotriene receptor antagonist
see anti-oestrogen.... oestrogen-receptor antagonist
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