Ulcer medications

Medicinal chemists have used isosterism for the design of safe, effective drug substances for many years. During the development of anti-ulcer medications, for example, it was found that metiamide (38) greatly reduced acid secretion in the gastrointestinal tract by antagonizing H2-receptor sites. Its potential as auseful anti-ulcer medication was lessened by adverse effects caused by the thiourea moiety, a toxicophore (Table 4.1). This moiety is essential for H2-receptor blockade, but bestows toxicity. 

Isosteric replacement of the thiourea moiety with the cyanoguanidine moiety gave cimetidine (39), a potent H2-receptor antagonist that lacks the toxicity of 38. Cimet-idine is a widely used anti-ulcer medication because of its effectiveness in treating ulcers and relative safety. It is noteworthy that in this example, this isosteric modification selectively reduced toxicity without affecting pharmacological activity. 

Because benzodiazepines, as a class, are usually equally effective in treating anxiety (in combination with cognitive-behavioral theraphy), psychiatrists usually select which of these drugs to prescribe based on its side effect profile. This means that the physician will weigh all the individual factors of each patient, and decide which drug is best suited for the patient s individual needs based on which side effects that person can or cannot tolerate. For example, some of the benzodiazepines are more easily processed by the liver. This may be particularly useful in patients taking birth control pills, propranolol, disulfuram, ulcer medications, and other drugs that may affect liver function. In such cases, lorazepam (Ativan) may be chosen because it has less of an effect on the liver. 

As discussed in Section 5.4.4, individuals consuming large quantities of antacid formulations, anti-ulcerative medications, buffered analgesics, or antidiarrheal medications are exposed to higher than background doses of aluminum in their diet. Lione (1985a) estimated that from 126 to 728 mg and 840 to 5,000 mg were possible daily doses of aluminum consumed in buffered aspirins for rheumatoid arthritis and antacid products, respectively. These doses are from 6 to 40 times and 42 to 250 times greater, respectively, than aluminum doses obtained from consumption of foods (20-24 mg/day). 

Oxidation of Sulfides to Sulfoxides an Anti-ulcer Medication... 

Diuretics, by increasing kidney output, deplete calcium, magnesium, potassium, and zinc. This, in turn, depletes energy and lowers immune function. Over-the-counter antacids, as well as the peptic ulcer medication cimetidine, reduce iron and calcium assimilation, vitamin Bj , and intrinsic factor (without which Bi2 can t be absorbed). Drugs prescribed for heart disease reduce libido, and some of them render men impotent. 

The xanHiine derivatives are contraindicated in Hiose wiHi known hypersensitivity, peptic ulcers, seizure disorders (unless well controlled with appropriate anticonvulsant medication), serious uncontrolled arrhytinnias, and hyperthyroidism. 

Specific anticholinergic drug are occasionally used in die medical treatment of peptic ulcer. These drug have been largely replaced by histamine H2 antagonists, which appear to be more effective and have fewer adverse drug reactions. 

These drug are used for the medical treatment of agastric or duodenal ulcer, gastric hypersecretory (excessive gastric secretion of hydrochloric acid) conditions, and GERD. These drug may also be used as prophylaxis of stress-related ulcers and acute upper GI bleeding in critically ill patients. 

Willow bark (weidenrinde, white willow, purple osier willow, crack willow) S lixalba, purpurea, fragilis Analgesic Adverse reactions are those associated with the salicylates Do not use with aspirin or other NSAIDs. Do not use in patients with peptic ulcers and other medical conditions in which the salicylates are contraindicated. 

In severe cases, or those refractory to treatment, truncal and limb weakness may be accompanied by involvement of masticatory, bulbar, and respiratory muscles. However the most life-threatening clinical manifestations are those affecting the gastrointestinal tract, since stomach ulceration can occur and death from perforation and peritonitis are not unknown. Medication with steroidal antiinflammatory agents is necessary but weakens the childrens resistance to infection, so that systemic spread of usually self-limiting disorders, such as candidiasis, may occasionally occur. 

NSAIDs are one of the most widely used classes of medications in the United States, particularly in the elderly.4 More than 20,000 deaths occur in the United States per year as a direct result of adverse events related to NSAID use. Chronic NSAID ingestion leads to symptoms of nausea and dyspepsia in nearly half of patients. Peptic ulceration occurs in up to 30% of patients who use NSAIDs chronically, with gastrointestinal bleeding or perforation occurring in 1.5% of patients who develop an ulcer. NSAID-related peptic ulcers usually occur in the stomach duodenal ulcers are much less common. 

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