Academic literature on the topic 'Paracetamol absorption'

The Absorption Ratio method involves measuring the absorbance at two wavelengths, namely the iso-absorptive point and the maximum wavelength. Its method could be an option in determining the level of a drug. The aim of this study was to determine whether the absorption ratio method can be used to determine the levels of paracetamol (PCT), propyphenazone (PRO) and caffeine (CAF) in tablet form. The absorption ratio method was used to determine the levels of the mixed drug compound without the separation stage and using the maximum wavelength and iso-absorptif point. The result of the study showed that the absorption ratio method used to solve multicomponent problems in tablet form can be performed and satisfy the validation requirements of the method according to international Conference on Harmonization Q2 (R1) (ICH) guidelines. The absorption ratio method was a simple and accurate to be used determine PCT, PRO, CAF in tablet form. Keywords : Paracetamol, propyphenazone, caffeine, absorption ratio

Antiemetics modify gastric emptying, a rate-limiting step in drug absorption. The absorption of effervescent paracetamol in water solution was studied in three groups of 10 female patients during acute migraine attacks. Paracetamol was preceded 30 min earlier by a rectal dose of metoclopramide, prochlorperazine maleate, or placebo. Each patient was retested with paracetamol when headache-free. Migraine attacks delayed slightly the absorption of paracetamol solution. Prior administration of rectal prochlorperazine had a minor delaying effect on paracetamol absorption. The peak concentration, the time to reach the peak, and the area under the time-concentration curve from 0 to 6 h of paracetamol were similar with the three treatments.

1 The disposition and kinetics of paracetamol, dextropropoxyphene and their metabolites were investigated in an addict who claimed to be taking 80–100 Distalgesic tablets daily regularly. 2 Plasma concentrations of paracetamol, dextropropoxyphene and their principal metabolites were measured after an oral dose of 15 Distalgesic tablets. 3 The absorption of paracetamol and dextropropoxyphene was rapid with peak plasma concentrations at 15 and 30 min respectively. The elimination half-life for paracetamol was 2.3 h. Nordextropropoxyphene remained at steady state with very high plasma concentrations (5 mg/l). The urinary excretion of paracetamol and metabolites was not abnormal. The total recovery of paracetamol was only 31% of the dose. 4 Apart from raised plasma γ-glutamyltransferase activity there was no biochemical evidence for paracetamol-induced hepatocellular damage despite ingestion of 97.5 g of paracetamol over the 11 days of the withdrawal period.

AbstractIn microwave drying technology, research into the dynamic absorbing properties of the powder is indispensable. In this study, the reflection loss coefficient of paracetamol powder under different temperature, water content, and thickness was calculated based on the principle of electromagnetic wave transmission. The results show that the absorption performance of powder fluctuates dynamically with a series of absorption peaks, and the position of the absorption peak shifts toward the smaller thickness direction as the water content increases or the temperature rises. Because of the influence of the powder thickness on absorbing efficiency, the powder thickness should be adjusted in real time to increase drying efficiency. This study provides the thickness range for which the absorption performance of paracetamol powder under different conditions is over 99%. This study is of great significance for understanding the drying mechanism and optimizing process parameters for microwave drying of pharmaceutical powder.

Several sophisticated techniques to study in vivo GI transit and regional absorption of pharmaceuticals are available and increasingly used. Examples of such methods are Magnetic Marker Monitoring (MMM) and local drug administration with remotely operated capsules. Another approach is the paracetamol and sulfapyridine double marker method which utilizes observed plasma concentrations of the two substances as markers for GI transit. Common for all of these methods is that they generate multiple types of observations e.g. tablet GI position, drug release and plasma concentrations of one or more substances. This thesis is based on the hypothesis that application of mechanistic nonlinear mixed-effect models could facilitate a better understanding of the interrelationship between such variables and result improved predictions of the processes involved in oral absorption. Mechanistic modeling approaches have been developed for application to data from MMM studies, paracetamol and sulfapyridine double marker studies and for linking in vitro and in vivo drug release. Models for integrating information about tablet GI transit, in vivo drug release and drug plasma concentrations measured in MMM studies was outlined and utilized to describe drug release and absorption properties along the GI tract for felodipine and the investigational drug AZD0837. A mechanistic link between in vitro and in vivo drug release was established by estimation of the mechanical stress in different regions of the GI tract in a unit equivalent to rotation speed in the in vitro experimental setup. The effect of atropine and erythromycin on gastric emptying and small intestinal transit was characterized with a semi-mechanistic model applied to double marker studies in fed and fasting dogs. The work with modeling of in vivo drug absorption has highlighted the need for, and led to, further development of mixed-effect modeling methodology with respect to model diagnostics and the handling of censored observations.

L’hypersensibilité incluant les allergies médicamenteuses est un des multiples effets secondaires médicamenteux. On note à la fois un sous-diagnostic de ces hypersensibilités, par non-déclaration des cas les plus bénins, et un sur-diagnostic, par utilisation systématique du terme « allergie » devant des symptômes survenant au cours d’un traitement. Un faux diagnostic d’allergie fondé exclusivement sur l’histoire clinique peut limiter les indications thérapeutiques chez les patients et conduire à une perte de chance par l’utilisation de médicaments moins efficaces, plus dangereux ou plus coûteux. De plus, une allergie à un médicament peut laisser penser que le patient est allergique à tous les médicaments de la même classe. Le test de provocation (TP) est considéré le « gold standard » pour identifier un médicament responsable d’une hypersensibilité médicamenteuse. Ce travail s’inscrit dans une démarche d’optimisation des TP basée sur les preuves, visant à la fois la satisfaction du patient et les coûts engendrés, tout en préservant la sécurité des tests. J’ai utilisé l’expérience de 20 ans recensée dans la base d’allergies médicamenteuses, DAHD (Drug Allergy and Hypersensitivity Database), j’ai exploité rétrospectivement les données cliniques, recensé les cas présents dans la base pour en extraire les TP positifs et j’ai réalisé une analyse de survie pour passer des protocoles de TP aux anti-inflammatoire non-stéroïdiens (AINS) d’une étape avec paliers purement empiriques, à un protocole basé sur des données (Article 1) en tenant compte des spécificités liées à ces médicaments (multitude de molécules impliquées, chacune avec un pouvoir hypersensibilisant clairement différent). Avec les conclusions obtenues pour ce premier travail, pour mon deuxième papier, j’ai repris des données brutes déjà existantes liées à l’expérience de l’équipe pour les hypersensibilités au paracétamol, et en suivant la même méthodologie, j’ai proposé des paliers optimaux raccourcis pour le TP au paracétamol (en surlignant la particularité de l’hypersensibilité aux AINS versus paracétamol) (Article 2) en appuyant sur les facteurs de risques pour un TP positif
Drug hypersensitivity (DH) including drug allergies is one of the many side effects of medications. The knowledge on DH is both influenced by an under-diagnosis (the non-reporting of the mildest cases) and over-diagnosis, by systematic use of the term "allergy" to symptoms occurring during a course of treatment, whether they are actually evocative of DH or not. A false diagnosis of DH based solely on clinical history may limit the therapeutic indications in patients and lead to a loss of chance through the use of less effective, more dangerous or more expensive drugs. The drug provocation test (DPT) is considered to be the "gold standard" to identify a drug responsible for DH. This work uses an original methodology for the DH field and is part of an evidence-based approach to achieve the optimization of DPT, aimed to both increase patient satisfaction and diminish the costs incurred by the allergy work-up, while preserving the DPT’s safety. I used the 20-year experience in the DAHD, the Drug Allergy and Hypersensitivity Database of the Allergy Unit in Montpellier, France, to retrospectively assess the clinical data, identify cases and extract positive DPT to NSAIDs. I then performed on these positive DPT a survival analysis in order to pass protocols from a stage with purely empirical increments of doses, to data-driven protocols (Article 1) taking into account the specificities related to these drugs (e.g., multitude of molecules involved, each with a clearly different hypersensitive potential). With the conclusions obtained for this first work, for my second paper, I took over already existing raw data related to the team's experience with paracetamol HS, and following a similar methodology, I proposed optimized, shortened thresholds for paracetamol DPT (Article 2)

Transpyloric flow is the final step in gastric emptying prior to intestinal absorption of nutrients and medications. The details of this process are still incompletely understood. Transpyloric flow is bi-directional, contrasting with the general perception of solely forward flow implied by studies of gross gastric emptying. The degree to which the patterns of bi-directional transpyloric flow reflect emptying of meals of varied physicochemical composition, its mechanical determinants and effect on delivery of oral medications have been evaluated by the studies presented in this thesis.

Poisons: general principles 180 Diagnosis of poisoning 182 Poisons: supportive care 183 Reducing absorption of poison 184 Antidotes for poisons 186 Opioid poisoning 188 Salicylate poisoning 189 Paracetamol poisoning 190 Tricyclic antidepressant poisoning 194 Benzodiazepine poisoning 196 Clomethiazole poisoning 196 Phenothiazine poisoning 196 Barbiturate poisoning ...

This chapter in the Oxford Handbook of Emergency Medicine encompasses toxicology in the emergency department (ED). It examines poisons in general, including diagnosis, supportive care, reducing absorption, and antidotes. Specific poisoning is explored in detail, through opioid, salicylate, paracetamol, tricyclic antidepressant, benzodiazepine, clomethiazole, phenothiazine, barbiturate, lithium, sulfonylurea, beta-blocker, calcium channel antagonist, digoxin, angiotensin-converting enzyme (ACE) inhibitor, theophylline, salbutamol, iron, ethanol, methanol, ethylene glycol, paraquat, petrol, paraffin, organophosphate, cyanide, carbon monoxide, chlorine, and CS gas (tear gas) poisoning. Chemical incidents are discussed, as well as accidental poisoning from plants, berries, mushrooms, and button batteries. It also examines novel psychoactive substances (NPS), recreational drugs, serotonin syndrome, and body packers.