Antipyrine

Antipyrine is an analgesic and antipyretic agent. Target: Others Antipyrine is an analgesic and antipyretic that has been given by mouth and as ear drops. Antipyrine is often used in testing the effects of other drugs or diseases on drug-metabolizing enzymes in the liver. Antipyrine was one of the first important synthetic drugs. antipyrine went into widespread clinical use as an antipyretic the same year it was synthesized. Two years after its introduction, reports began to appear of its analgesic effects and in the succeeding years, as the use of antipyrine as an antipyretic declined, it gained considerable popularity as an analgesic. The plasma halflife of antipyrine is significantly longer and the clearance significantly lower in the elderly group. This finding of an impaired metabolism of antipyrine in the elderly has since been confirmed in a much larger study and subsequently other drugs have been shown to be metabolized more slowly in this age group [1].

References:
[1]. Stevenson, I.H., Factors influencing antipyrine elimination. Br J Clin Pharmacol, 1977. 4(3): p. 261-5.

Transplacental transport of paracetamol and its phase II metabolites using the ex vivo placenta perfusion model.[Pubmed:30849458]

Toxicol Appl Pharmacol. 2019 May 1;370:14-23.

In Europe, 50-60% of pregnant women uses paracetamol (PCM), also known as acetaminophen. While it was considered to be safe, recent studies have shown an association between prenatal exposure to PCM and increased incidences of autism, cryptorchidism, asthma and ADHD. In this study the transplacental transfer of PCM and its metabolites was investigated using an ex vivo human placenta perfusion model (closed circuit; n=38). Maternal-to-foetal (M-F) and foetal-to-maternal (F-M) transplacental transfer was determined at a concentration correlating with the maximum and steady state concentration in normal clinical use. Antipyrine (AP) was added as reference compound. Samples of the foetal and maternal perfusion medium were taken until 210 (PCM) or 360min (paracetamol sulphate (PCM-S) and paracetamol glucuronide (PCM-G). PCM and AP concentrations reached an equilibrium between foetal and maternal compartments within the duration of the perfusion experiment and irrespective of the transfer direction. The percentage placental transfer of PCM was 45% (M-F and F-M). For PCM-S, transfer was 39% (M-F) and 28% (F-M), while the PCM-G transfer was 34% (M-F) and 25% (F-M). During placenta perfusions with the metabolites slight conversion (3.5-4.1%) to PCM was observed. In conclusion, PCM crosses the placental barrier rapidly via passive diffusion. Differences in flow rate and villous placental structure explain the significantly faster M-F transfer than F-M transfer of PCM. The larger and more hydrophilic molecules PCM-S and PCM-G cross the placenta at a significantly lower rate. Moreover, their F-M transport is about 40% slower than M-F transport, suggesting involvement of a transporter.

Determination of the Transplacental Transfer of Paclitaxel and Antipyrine by High Performance Liquid Chromatography Coupled with Photodiode Array Detector.[Pubmed:30774296]

J Liq Chromatogr Relat Technol. 2018;41(5):232-238.

Ex vivo placental perfusion experiments are important in understanding the quantity and mechanisms of xenobiotic transport to the fetus during pregnancy. Our study demonstrates that paclitaxel and Antipyrine concentrations in placental perfusion medium containing physiological concentrations of human serum albumin during pregnancy (30 mg/mL) can be quantified by RP-HPLC and UV detection. A liquid-liquid extraction method was developed for the quantification of paclitaxel and celecoxib (internal standard) from perfusion medium. Antipyrine, which is a necessary marker in placental perfusions for determining the validity of experiments and calculating the clearance index of xenobiotics, was also analyzed by HPLC and UV detection. Antipyrine concentrations were determined by HPLC after precipitating the perfusion medium in acetonitrile and separating the precipitated proteins by centrifugation. Concentrations were fitted to linear regressions with R(2) values approaching 1. Lower limits of detection for paclitaxel and Antipyrine were 100 ng/mL and 200 ng/mL, respectively. Both methods demonstrated high intra-day and inter-day precision and trueness. Additionally, the use of these methods was demonstrated in a placental perfusion experiment using Taxol((R)) (paclitaxel dissolved in Cremophor-EL). The fetal transfer rate of Taxol was 6.6% after 1 hour.

History of NSAID Use in the Treatment of Headaches Pre and Post-industrial Revolution in the United States: the Rise and Fall of Antipyrine, Salicylic Acid, and Acetanilide.[Pubmed:30673879]

Curr Pain Headache Rep. 2019 Jan 23;23(1):6.

PURPOSE OF REVIEW: Non-steroid anti-inflammatory drugs (NSAIDs) constitute a vital class of medications in today's headache regimen. However, up until the nineteenth century, they were largely unknown to most of the medical community. The purpose of this review is to explore the evolution of NSAIDs in the treatment of headaches spurred on by the Industrial Revolution in the USA. RECENT FINDINGS: The currently available data on the impact of NSAIDs reflects their significant contribution to headache treatment. The emergence of mass production spurred on by the Industrial Revolution, lead to widespread use of Antipyrine, salicylic acid, and acetanilide. However, along with it came the growing awareness of consumer safety, leading to their ultimate downfall, and the subsequent birth of the Food and Drug Act.

Differential Metal Ion Sensing by an Antipyrine Derivative in Aqueous and beta-Cyclodextrin Media: Selectivity Tuning by beta-Cyclodextrin.[Pubmed:30412380]

Anal Chem. 2018 Nov 20;90(22):13607-13615.

beta-Cyclodextrin (beta-CD) is a nontoxic cyclic oligosachcharide that can encapsulate all or part of organic molecules of appropriate size and specific shape through noncovalent interaction. Herein, we report the influence of beta-CD complex formation of an Antipyrine derivative on its metal ion sensing behavior. In aqueous solution, the Antipyrine shows a turn-on fluorescence sensing of vanadyl ion, and in cyclodextrin medium it senses aluminum ion. The compound shows an unusual fluorescence quenching on binding with beta-cyclodextrin (log KSV = 2.34 +/- 0.02). The differential metal ion sensing is due to the partial blocking of the chelating moiety by the cyclodextrin molecule. The structure of the Antipyrine-cyclodextrin complex is optimized by two-dimensional rotating-frame Overhauser effect spectroscopy. The binding constant is determined by isothermal titration calorimetry (log K = 2.09 +/- 0.004). The metal ion binding site is optimized by quanutm mechanical calculations. The lower limit of detection of vanadyl and aluminum ions, respectively, are 5 x 10(-8) and 5 x 10(-7) mol dm(-3). This is the first report of selectivity of two different cations by a chemosensor in water and in beta-CD.