Antipyretic Agents

Scheme 19 contains all the reactions observed in different examples, none being so complex (B-76MI40402). Most studies deal with the methylation of 3-methyl-1-phenyl-pyrazolone, since in this case one of the products obtained is antipyrine (2,3-dimethyl-l-phenyl-3-pyrazolin-5-one), one of the classical antipyretic agents (Section 4.04.4.1.1). 

Antipyretic agents are used for the treatment of fever. The most commonly used antipyretics are acetylsa-licylic acid and paracetamol (synonym acetaminophen). 

From a series of 5,6-diphenylpyridazines prepared in Italy [91], chloro derivatives of type (20, R = 4-Me2NC6H4, 4-MeOC6H4) have been found to be anti-inflammatory, analgesic and antipyretic agents superior to phenylbutazone when tested in mice or rats. 

The application of a mild topical corticosteroid, such as hydrocortisone, is effective in patients presenting with multiple mosquito bites. Paracetamol, which is an antipyretic agent is not indicated in mosquito bites. Fusidic acid cream is an anti-infective agent and is indicated if the mosquito bites have been scratched and there is risk of infection. Benzocaine (anaesthetic) and mepyramine (antihistamine) may relieve itchiness but are less effective in multiple mosquito bites than hydrocortisone. 

The salicylates are also potent antipyretic agents, with the exception of diflunisal, which is only weakly active. Aspirin acts at two distinct but related sites. It decreases prostaglandin-induced fever in response to pyrogens and induces a decrease in interleukin-1 modulation of the hypothalamic control of body temperature. Thus, the hypothalamic control of body temperature returns, vasodilation occurs, heat dissipates, and fever decreases. Other uses of aspirin include inhibition of platelet aggregation via inhibition of thromboxanes, which has been shown to decrease the incidence of blood clots, myocardial infarction, and transient ischemic attacks. 

Tolmetin (Tolectin) is an antiinflammatory, analgesic, and antipyretic agent that produces the usual gastric distress and ulceration observed with NSAIDs. However, tolmetin is better tolerated than aspirin and produces less tinnitus and vertigo. Tolmetin is a substitute for indomethacin in indomethacin-sensitive patients and is unique among such drugs in that it can be used to treat juvenile arthritis. 

Although equivalent to aspirin as an effective analgesic and antipyretic agent, acetaminophen differs in that it lacks anti-inflammatory properties. It does not affect uric acid levels and lacks... 

Antipyretic agents, (I.2.4]triazolo[l,5-a]-pyrimidines, 57, 126 Antipyrine, fluorination by acetyl hypofluorite, 59, 4... 

As early as in the tenth century in Middle Eastern medicine, the hemp was used as an antipyretic agent (cited by Lozano 2001). Moreau (1845) also mentioned the hypothermic effect of marijuana. 

Tolmetin is an antiinflammatory, analgesic, and antipyretic agent introduced into clinical practice in the United States in 1976. Tolmetin, in recommended doses (200 to 600 mg three times a day), appears to be approximately equivalent in efficacy to moderate doses of aspirin. Tolmetin possesses typical tNSAID properties and side effects... 

The terephthaloylisoxazolidine (82) is antiphlogistic, analgesic, and effective as an antipyretic agent.19 Similarly, compounds 83 are antiinflammatory, antipyretic, and diuretic.159... 

Aspirin and NSAIDs inhibit the COX enzymes and prostaglandin production they do not inhibit the lipoxygenase pathways of AA metabolism and hence do not suppress LT formation (see Chapter 25). Table 26-1 provides a classification of NSAIDs and other analgesic and antipyretic agents based on their chemical structures. 

Acetaminophen (paracetamol JV-acetyl-p-aminophenoF, TYLENOL, others) is an effective alternative to aspirin as an analgesic-antipyretic agent however, its anti-inflammatory effects are much weaker. While it is indicated for pain relief in patients with noninflammatory osteoarthritis, it is not a suitable substitute for aspirin or other NSAIDs in chronic inflammatory conditions such as rheumatoid arthritis. Acetaminophen is well tolerated and has a low incidence of GI side effects. It is available without a prescription. Acute overdosage can cause severe hepatic damage, and the number of accidental or deliberate poisonings with acetaminophen continues to grow. Chronic use of less than 2 g/day is not typically associated with hepatic dysfunction. 

C. Effects Acetaminophen is an analgesic and antipyretic agent lacking anti-inflammatory or antiplatelet effects. 

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