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Biomedical subjects

S S Adams

Publications and source records attributed to S S Adams.

At least 19 recordsLinked to original sources

The propionic acids: a personal perspective.

In searching during the early 1950s for new drugs for the treatment of rheumatoid arthritis, little information was available to allow a rational approach. The mode of action of the few drugs available was unknown and even the analgesic action of aspirin could not be demonstrated in animals. A speculative concept was developed that aspirin possessed a specific unidentified action in rheumatoid arthritis and that this and its analgesic properties were related to its ability to delay the development of ultraviolet (UV) erythema in the guinea pig. A series of substituted phenoxypropionic acids proved to be active as antierythemic agents, but the most potent was inactive clinically in rheumatoid arthritis. Refinements to the testing systems led to a series of substituted phenylacetic acids, three of which although active in rheumatoid arthritis produced unacceptable adverse reactions (ADRs). Attempts to relate laboratory data to clinical ADRs suggested that the substituted phenylpropionic acids (originally rejected because of concerns about toxicity) might be better tolerated than we had anticipated. Ibuprofen was selected from this large group. It was proven to be effective and well tolerated and became "the first of the propionics" when it was launched in 1969. In the 1970s, ibuprofen proved to be effective as a prescription drug in a range of painful nonrheumatic conditions and on the basis of its good safety record was approved as an OTC analgesic in 1983 in the United Kingdom and in 1984 in the USA. It has proven to be popular and effective and much safer than aspirin or acetaminophen in overdosage.

Analgesia

Effects of lys-beta-urogastrone in vivo.

Lys-beta-urogastrone, an analogue of human beta-urogastrone with an additional N-terminal lysine, was shown to have similar effects in mice and sheep to mouse epidermal growth factor (mEGF). Lys-beta-urogastrone in doses of 0.18-3.24 micrograms g-1 body weight caused both precocious separation of eyelids and eruption of incisors in neonatal mice. In 17 sheep, intravenous infusion of the urogastrone analogue over c. 24 h led, towards the end of infusion, to erythema of the muzzle, caused reductions in voluntary food intake (with doses greater than or equal to 50 micrograms kg-1) and generally easier manual harvesting of the fleece (with infusions greater than or equal to 81 micrograms kg-1), with spontaneous shedding of the fleece (c. 14 days after infusions of greater than or equal to 116 micrograms kg-1). In five sheep infusions of 25, 38, 50, 83 and 118 micrograms kg-1 fleece-free body weight, plasma concentrations of lys-beta-urogastrone were near maximal 20 h after the infusions started and were, respectively, 1.1, 1.7, 5.5, 18 and 79 micrograms l-1 plasma. Plasma concentrations of gastrin, somatostatin and pancreatic polypeptide were determined in these five sheep. Plasma gastrin rose sixfold by the end of infusions of 25 micrograms kg-1 of the urogastrone analogue, and tenfold with the higher doses of infusion. Although plasma somatostatin concentrations were variable, a consistent trend was observed; lower levels were apparent during the lys-beta-urogastrone infusions. There was no discernible trend in pancreatic polypeptide concentrations.

Animals

The disposition and metabolism of flurbiprofen in several species including man.

Flurbiprofen was rapidly absorbed in all species studied. 2. Half-lives of elimination measured 0 to 12 h after a single dose were: mouse 3.4 h, rat 2.5 h, dog 10.1 h, baboon 3.1 h and man 3.9 h. A second phase of elimination was seen in the dog. Flurbiprofen accumulated in the circulation of the dog on repeated dosing. 3. After dosing with [14C]flurbiprofen, tissue levels of radioactivity in dog and baboon were similar to that in plasma. In the rat, levels were slightly elevated in liver, kidney, large intestine and thyroid after repeated dosing. 4. The dog excreted equal amounts of radioactivity in urine and faeces. In other species renal excretion was the more important route. 5. Six metabolites have been detected, the most important being: 2-(2-fluoro-4'-hydroxy-4-biphenylyl)propionic acid (metabolite 1), 2-(i-fluoro-3',4'-dihydroxy-4-biphenylyl)propionic acid (metabolite 2) and 2-(2-fluoro-3'-hydroxy-4'-methoxy-4-biphenylyl)propionic acid (metabolite 3). The proportions of the metabolites and the extents of their conjugation varied among the species. 6. Metabolites were detected in the circulation of rat, mouse and baboon but not in dog and man. 7. Flurbiprofen did not affect the hepatic drug-metabolizing enzyme system of rat. 8. Flurbiprofen was extensively bound to serum protein of rat, dog, baboon and man.

Adolescent

Inhibition of prostaglandin synthesis and leucocyte migration by flurbiprofen.

The carrageenan air pouch technique in the rat was used to investigate the effects of flurbiprofen, a non-steroidal anti-inflammatory agent, on prostaglandin production and leucocyte migration. tthere is a suggestion that flurbiprofen was capable of inhibiting prostaglandin synthesis at doses lower than those which were effective in reducing leucocyte migration. Therefore, these two effects may reflect independent actions of the drug. The possible clinical relevance of these experiments has been noted since the effects of flurbiprofen on prostaglandin synthesis and leucocyte migration are produced in the rat at peak plasma concentrations which are less than those found in man after a single dose of 50 mg.

Animals

Some biological properties of flurbiprofen, an anti-inflammatory, analgesic and antipyretic agent.

2-(2-Fluoro-4-biphenyl)propionic acid (flurbiprofen) possesses peripheral analgesic, anti-inflammatory and antipyretic properties. It does not possess glucocorticoid or adrenocortical-stimulating properties. It is a highly potent agent which in acute pharmacological test systems produced a significant pharmacological effect in single oral doses varying from 0.04 to 0.47 mg/kg. The peak plasma concentrations attained after these doses were generally of the order of 1 to 3 mug/ml. Doses of 0.33 mg/kg/day, which gave peak plasma concentrations of 0.6 mug/ml, produced a significant inhibition of rat adjuvant arthritis, both developing and established. The very shallow dose-response curves for flurbiprofen compared with acetylsalicylic acid, especially in the mouse and the rat test systems, are not due to an unreliable or abnormal absorption, which suggests that in these species the mode of action of flurbiprofen is not identical with that of acetylsalicylic acid.

Adrenalectomy