China
Africa
Explore chapters and articles related to this topic
Miscellaneous
Published in Bobby Krishnachetty, Abdul Syed, Harriet Scott, Applied Anatomy for the FRCA, 2020
Bobby Krishnachetty, Abdul Syed, Harriet Scott
Effects on drug action Absent response of the heart to drugs that work by blocking the parasympathetic supply, i.e. glycopyrronium and atropine. Drugs that have a direct effect on the heart should be used instead (isoprenaline, glucagon, adrenaline and noradrenaline).Increased effect of certain drugs such as adrenaline and noradrenaline as there will be no reflex reaction of a reduced heart rate when the blood pressure increases
FDA Regulatory Acceptance of Bayesian Statistics
Published in Emmanuel Lesaffre, Gianluca Baio, Bruno Boulanger, Bayesian Methods in Pharmaceutical Research, 2020
For a pharmaceutical product, there is often little prior information derived from similar products since a similar pharmaceutical product often may have very different safety and efficacy profiles. The drug action is pharmacological and systemic and in contrast the device mechanism of action is usually physical, well-understood and local.
Historical Notes
Published in Albert A. Kurland, S. Joseph Mulé, Psychiatric Aspects of Opiate Dependence, 2019
Albert A. Kurland, S. Joseph Mulé
Altered biological disposition entails some changes in absorption, metabolism, excretion, and distribution, resulting in a change in the drug concentration of the active drug molecules at the site of drug action. The cellular mechanisms of particular cells on which the drug acts may be made less responsive. This might be brought about by the interaction with chemically specific sites or receptors located on the surface or within the cell and arbitrarily designated as cellular mechanisms of tolerance. The homeostatic mechanisms concerned with the maintenance of the constancy of the internal environment have their feedback of sensitive controlled mechanisms and/or the use of psychophysiological mechanisms altered in some manner, resulting in a state where, although the drug continues to exert its effect at the site of action, the overall response could be diminished by the adjustments taking place in other cells. This tends to counteract the overall response affecting physiologic as well as psychologic learning mechanisms of adjustment.
Herb–drug interactions: a mechanistic approach
Published in Drug and Chemical Toxicology, 2022
Ajay Kumar Sharma, Vijay Kumar Kapoor, Gurjot Kaur
Essentially, the extent of drug action is dependent on active drug molecules at the site of action which may be further dependent on drug’s metabolism in the body (liver) by enzyme systems. Cytochrome P450 (CYP) isoforms such as CYP1A1/2, CYP2B6, CYP2C8/9/19, CYP2D6, CYP2E1, CYP3A4/5, and CYP4A, are well reported to be important in the biotransformation of xenobiotics and endobiotics (Table 3). Interestingly, CYP450 enzymes showed the highest interactions (16 herbs in total) with the currently used herbs in the Indian medicinal systems. These interactions may have significant effects on the drugs that are taken in conjunction with the above herbs and are known as either substrates, inhibitors or inducers of the above-mentioned CYPs (Table 6). Table 6 describes the top four CYP450 enzymes and their currently known drug substrates, drug inhibitors and drug inducers. The herbs listed in Table 3 may have synergistic and/or antagonistic effects on the drug partners of these CYPs (Table 6). Such interactions have already been observed for Curcuma longa and Andrographis paniculata where CYP-mediated hydroxylation of tolbutamide, a CYP2C9 substrate, was inhibited either by alcoholic extract of the herb or by the isolated phytochemical constituent (andrographolide from Andrographis paniculata) (Al-Jenoobi 2010, Pekthong et al.2008).
The safety of available treatment options for short bowel syndrome and unmet needs
Published in Expert Opinion on Drug Safety, 2021
Loris Pironi, Emanuel Raschi, Anna Simona Sasdelli
Safety of medications is a multi-faceted issue, and two main aspects should be mentioned: 1) intrinsic toxicity of the active substance, caused by the mechanism of drug action, with on- and off-target effects depending on relevant receptor selectivity; 2) detrimental effects by nutritional supplements (e.g. vitamins and electrolytes) due to interference with the absorption of concomitant drugs and/or suboptimal restoration of deficiencies. In this scenario, routine monitoring of vitamins, calcium, potassium and magnesium, as well as plasma concentrations of drug with narrow therapeutic index (e.g. levothyroxine) are required. Gastric hypersecretion and lack of sufficient contact time with the intestinal mucosa leads to insufficient absorption of drugs such as omeprazole and loperamide, thus higher-than-recommended doses may be warranted [21]. Furthermore, clinicians should consider that excipients, usually considered to be inert from a pharmacological point of view, may pose safety concerns, especially, sucrose, saccharin and lactose [22]. Caution is needed in case of drug switches (including generic drugs) to prevent the occurrence of unwanted side effects: relevant SPCs of proton pump inhibitors (PPIs), loperamide, and prokinetics contain specific precautions to avoid their use in case of intolerance to some sugars, rare hereditary problems of galactose/fructose intolerance, sucrose-isomaltase insufficiency, the lactase deficiency typically observed among Lapp people or glucose-galactose malabsorption [22].
Synthesis and therapeutic delivery approaches for praziquantel: a patent review (2010-present)
Published in Expert Opinion on Therapeutic Patents, 2021
Tayo A. Adekiya, Pradeep Kumar, Pierre P.D. Kondiah, Viness Pillay, Yahya E. Choonara
Thus, the integration of nanomedicine approach using the drug delivery systems in infectious diseases treatment has posed several advantageous effects such as, better disease targeting most especially intracellular pathogens [52–54]. Others include longer time of drug action, the ability of the drug to cross membranes and enter cells, reduction of adverse effect, and cost-effectiveness from lower doses [52–54]. Recently, several studies have employed nanotechnology approach in improving the bioavailability and therapeutic efficacy of praziquantel for the treatment of schistosomiasis (Table 2). A study conducted by Amara and coworkers demonstrated that praziquantel-lipid nanocapsules (LNCs) with postabsorption targeting ability proved to be highly effective as oral nanocarriers for a large dose drug, PZQ. The study also showed that a single oral dose of PZQ-LNCs (250 mg/kg) significantly enhanced PZQ anti-schistosomal activity in S. mansoni infected mice [55]. In another related study by Frezza and coworker [48], it was revealed that PZQ containing liposome improved the efficacy of treatment with liposomes-PZQ (lip.PZQ) at 300 mg/kg on S. mansoni, BH strain when administered 45 days following infection when compared with the untreated group and the groups treated with free PZQ. Their observation showed that the lip.PZQ has a greater bioavailability in the host organism; the preferred target of the lip.PZQ is the liver, and lip.PZQ is better absorbed by the tegument of S. mansoni, which has an affinity for phospholipids [56].