Salicylates are popular anti-inflammatory agents not only because of their ability to block the inflammatory response, but also because of their antipyretic (fever-blocking) and analgesic (pain-blocking) properties. Salicylates are some of the oldest anti-inflammatory drugs used. They were extracted from willow bark, poplar trees, and other plants by ancient peoples to treat fever, pain, and what we now call inflammation. They are generally available without prescription and are relatively nontoxic when used as directed. Aspirin (Bayer, Empirin, and others), which is available OTC, is one of the most widely used drugs for treating inflammatory conditions.
Additional synthetic salicylates include balsalazide (Colazal), choline magnesium trisalicylate (Tricosal), diflunisal (Dolobid), mesalamine (Pentasa and others), olsalazine (Dipentum), salsalate (Argesic and others), and sodium thiosalicylate (Rexolate). A person who does not respond to one salicylate may respond to a different one.
Salicylates inhibit the synthesis of prostaglandin, an important mediator of the inflammatory reaction. The antipyretic effect of salicylates may be related to blocking of a prostaglandin mediator of pyrogens (chemicals that cause an increase in body temperature and that are released by active white blood cells) at the thermoregulatory center of the hypothalamus. At low levels, aspirin also affects platelet aggregation by inhibiting the synthesis of thromboxane A2, a potent vasoconstrictor that normally increases platelet aggregation and blood clot formation. At higher levels, aspirin inhibits the synthesis of prostacyclin, a vasodilator that inhibits platelet aggregation.
Salicylates are indicated for the treatment of mild to moderate pain, fever, and numerous inflammatory conditions, including rheumatoid arthritis and osteoarthritis.
轻度至中度疼痛、发烧和多种炎症疾病--包括类风湿关节炎和骨关节炎--的治疗都需要水杨酸盐类药。
Pharmacokinetics
药代动力学
Salicylates are readily absorbed directly from the stomach, reaching peak levels within 5 to 30 minutes. They are metabolized in the liver and excreted in the urine, with a half-life of 15 minutes to 12 hours, depending on the salicylate. Salicylates cross the placenta and enter breast milk; they are not indicated for use during pregnancy or lactation because of the potential adverse effects on the neonate and associated bleeding risks for the mother.
Salicylates are contraindicated in the presence of known allergy to salicylates, other NSAIDs (more common with a history of nasal polyps, asthma, or chronic urticaria), or tartrazine (a dye that has a cross-sensitivity with aspirin) because of the risk of allergic reaction; bleeding abnormalities because of the changes in platelet aggregation associated with these drugs; impaired renal function because the drug is excreted in the urine; chickenpox or influenza because of the risk of Reye syndrome in children and teenagers; surgery or other invasive procedures scheduled within 1 week because of the risk of increased bleeding; and pregnancy or lactation because of the potential adverse effects on the neonate or mother.
salicylates – n. 水杨酸盐类
antipyretic – a. 解热的
analgesic – a. 镇痛的
property – n. 特性
extract -- v. 提炼
willow – n. 柳树
poplar – n. 白杨树
Bayer – n. 拜尔
Empirin – n. 安匹林
balsalazide –巴柳氮
Colazal – n. 巴柳氮二钠
choline magnesium trisalicylate –三水杨酸胆碱镁
Tricosal – n. 三水杨酸胆碱镁片剂
diflunisal – n. 二氟尼柳
Dolobid – n. 二氟尼柳商品名
mesalamine – n. 氨水杨酸
Pentasa – n. 颇得斯安
olsalazine – n. 奥沙拉秦
Dipentum – n. 奥沙拉秦钠胶囊
salsalate – n. 双水杨酯
Argesic – n. 水杨酸甲酯和三乙醇胺软膏
sodium thiosalicylate – n. 硫柳酸钠
Rexolate – n. 硫柳酸钠商品名
pyrogens – n. 热原
thromboxane – n. 血栓烷
thromboxane A2 --血栓烷a2
★Video ★
Salicylates
★Test ★
1. A 22-year-old woman ingests an entire bottle of acetaminophen in an attempted suicide. She unexpectedly feels well for the next 24 h, at which time her boyfriend discovers what she has done and takes her to the ER. The toxic metabolite of acetaminophen exerts its deleterious effect by what mechanism?
A. Depletion of endogenous antioxidant
B. Hapten formation leading to autoantibody production
C. Inhibition of cytochrome C oxidase
D. Ischemia from decreased hepatic blood flow 2. A 60-year-old man with agitation is hospitalized on the medicine service for hyponatremia. He is being treated with intravenous fluids and haloperidol. He develops new onset of tremors and difficulty with ambulation and gait disturbance. What is the most likely explanation for these findings?
A. Iatrogenic
B. Infection
C. Neoplastic process
D. Viral encephalitis
答案 Key to Questions
1. A: Depletion of endogenous antioxidant.
Acetaminophen metabolism follows one of two pathways in the liver. Most (more than 90%) undergoes phase II metabolism directly and is excreted via the kidney. The remainder undergoes phase I metabolism by CYP1A2 or CYP2E1 to produce NAPQI, the toxic metabolite of acetaminophen. NAPQI requires glutathione for its next step of metabolism. Excess acetaminophen in the body produces so much NAPQI that liver glutathione (a natural, endogenous antioxidant) is depleted. Oxidative damage then occurs.
2. A: Iatrogenic.
Parkinsonian symptoms infrequently follow viral encephalitis or multiple small vascular lesions. Drugs such as the phenothiazines and haloperidol, whose major pharmacologic action is blockade of dopamine receptors in the brain, may also produce parkinsonian symptoms. These drugs should not be used in patients with Parkinson’s disease. This patient is being given haloperidol to treat agitation, which likely caused the parkinsonian symptoms.
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