Quantification of Drug Action
the dose at which one-half of the group has responded. The dose range encompassing the dose-frequency relationship reflects the variation in individual sensitivity to the drug. Although similar in shape, a dose-frequency relationship has, thus, a different meaning than does a dose-effect relationship. The latter can be evaluated in one individual and results from an intraindividual dependency of the effect on drug concentration.
Ebook English in Pharmacy - Part 1 include all of the following: pharmacy and pharmacists, pharmacology, types os drugs, terminology of drug action, FDA and AME, before using medicines, what customers should know,...
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Systematic analysis of genome-wide fitness data in yeast reveals novel gene function and drug action...
With publication of the human genome has come an
experiment in reductionism for drug discovery. With the
evaluation of the number and quality of new drug
treatments from this approach has come a reevaluation
of target-based versus systems-based strategies. Pharmacology,
historically rooted in systems-based approaches
and designed to give systems-independent measures
of drug activity, is suitably poised to be a major (if
not the major) tool in this new environment of drug
Drugs for the Treatment of Peptic Ulcers
cipitated antacid or, phosphate depletion of the body with excessive intake of Al(OH)3. Na+ ions remain in solution even in the presence of HCO3–-rich pancreatic secretions and are subject to absorption, like HCO3–. Because of the uptake of Na+, use of NaHCO3 must be avoided in conditions requiring restriction of NaCl intake, such as hypertension, cardiac failure, and edema. Since food has a buffering effect, antacids are taken between meals (e.g., 1 and 3 h after meals and at bedtime). Nonabsorbable antacids are preferred.
Propionic acid derivative analgesic-antipyretics ( Table 2.1) are non-steroidal and antiinflammatory drugs. As one of mechanisms of their pharmacological actions, inhibition of prostaglandin biosynthesis can be mentioned. Although fatal cases due to propionic acid derivative analgesic-antipyretics are not many in the world, the incidence of poisoning (including survived cases) by this drug group is relatively high among therapeutic drugs in Japan .
Methanol (methyl alcohol) poisoning accidents take place most frequently by drinking it in mistake for ethanol. Methanol poisoning is not due to the effect of methanol itself, but due to toxicity of its metabolites. Methanol is rapidly absorbed into human body through the airway mucous membranes, digestive tract mucous membranes or the skin; it is metabolized into formaldehyde (formalin, HCHO) and then formic acid (HCOOH) by the actions of alcohol dehydrogenase and aldehyde dehydrogenase, respectively.
Among many carbamate pesticides commercially available in Japan, those with relatively high toxicities are shown in Table 4.1 . Carbamate pesticides are generally classified into N-methylcarbamate insecticides and N-allylcarbamate herbicides in view of their chemical structures and biological actions. The number of fatalities due to poisoning by carbamate pesticides is 50–100 every year in Japan; many of them are poisoned by methomyl .
The sixth edition of Modern Pharmacology With
Clinical Applications continues our commitment
to enlisting experts in pharmacology to provide
a textbook that is up-to-date and comprehensive. Designed
to be used during a single semester, the book focuses
on the clinical application of drugs within a context
of the major principles of pharmacology. It is meant
to serve students in medicine, osteopathy, dentistry,
pharmacy, and advanced nursing, as well as undergraduate
As many as 5,000–6,000 mushroom species are growing in the world. Among them, only about 1,000 species are named; the majority of them are unnamed. The number of species of edible mushrooms in Japan is about 300; that of toxic mushrooms is said to be about 30. Various types of toxic mushrooms exist; some show high toxicity, while others show hallucinogenic actions. Morphological and chemical analyses for mushrooms are occasionally required in forensic science practice.
The era of pharmacology, the science concerned with the understanding of drug action, began only about 150 years
ago when Rudolf Buchheim established the first pharmacological laboratory in Dorpat (now, Tartu, Estonia). Since
then, pharmacology has always been a lively discipline with “open borders”, reaching out not only to other life
sciences such as physiology, biochemistry, cell biology and clinical medicine, but also to chemistry and physics.
Local anaesthetics reversibly block neural transmission in local tissues. The drugs are bound with specific receptors located inside the sodium channels of cell membranes, and thus block the permeability of sodium ions; this is the mechanism of anaesthetic action of these drugs. As the history of local anaesthetics, Von Anrep discovered the local anaesthetic action of an alkaloid cocaine being contained in the leaves of Erythroxylon coca. Then, Karl Koller used cocaine as a local anaesthetic in ophthalmological surgery.
As coumarin rodenticides, warfarin, coumatetralyl, coumafuryl, coumachlor and bromadiolone are commercially available in Japan. The coumarin rodenticides do not show direct anticoagulant action causing bleeding, but inhibit the metabolic cycle of vitamin K; the inhibition causes the interference with protein biosynthesis of vitamin K-dependent coagulant factors (II, VII, IX and X factors) in the liver, which are very important for the blood coagulation system. The lowered coagulant factors cause the bleeding deaths of the rodents .
An organophosphorus nerve agent VX (O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate, Figure 2.1) shows potent inhibitory action on acetylcholinesterase; its development, production, stockpiling and use are being prohibited by the CWC international treaty as a chemical weapon together with those of sarin and soman. In addition, even material compounds for VX synthesis are being also controlled strictly. In the world history, there had been no records on the use of VX in any international dispute.
Phenothiazine drugs, including chlorpromazine and levomepromazine, have been being widely used as neuroleptics (major tranquilizers), antiparkinsonian drugs and antihistaminics for a long time . Table 1.1 shows chemical structures of representative phenothiazines. These drugs show blocking action on D2 receptors of dopaminergic neurons; there is close relationship between the receptor blocking and tranquilizing actions. The dopamine D2 receptor-blocking actions provoke extrapyramidal symptoms, such as muscular stiffness, tremor and ptyalism.
Surfactants can be classified into cationic, anionic and nonionic ones. Benzalkonium chlorides are cationic surfectants and being widely used as a disinfectant and germicide using their strong protein-denaturing action. Especially in hospitals, 10 % solution of benzalkonium chloride mixture is being usually used; it is diluted to 0.05–0.1 % solution to be used for various types of disinfection. The drugs are contained in gargles and preservative solutions for contact lenses.
Chemical weapons (chemical warfare agents), such as sarin and soman, were developed to kill or injure humans by their toxic actions. They are called “nuclear weapon of the poor”, because the weapons are relatively stable during storage, cheap for production and relatively easily synthesized with basic knowledge on organic chemistry. Main advanced countries are making efforts to reduce chemical weapons existing in the world on the basis of the Chemical Weapons Convention (CWC), after the Iran-Iraq War and the Gulf War.
Nitrate and nitrite compounds are being used for various purposes, such as coronary artery dilators, coloring reagents for meat, rust preventives, fertilizers and explosives. When a nitrate salt is ingested by a human, nitric acid is converted into nitrous acid by the action of nitric acidreducing bacteria inhabiting the upper digestive tract; the nitrous acid oxidizes the divalent ferrous ion of hemoglobin to produce methemoglobin a with the trivalent ferric ion.
can be classified according to their respective primary mode of action (color tone in 2 and 3). When bacterial growth remains unaffected by an antibacterial drug, bacterial resistance is present. This may occur because of certain metabolic characteristics that confer a natural insensitivity to the drug on a particular strain of bacteria (natural resistance). Depending on whether a drug affects only a few or numerous types of bacteria, the terms narrow-spectrum (e.g., penicillin G) or broad-spectrum (e.g., tetracyclines) antibiotic are applied.
Hypochlorite a (HClO) is a weak acid, which exerts oxidative action; it is being widely used in the salt forms for bleaching and other purposes. Sodium hypochlorite (NaClO) aqueous solution is usually used as a disinfectant, bleaching agent, fungicide and ink eraser, and is thus usually included in detergents for laundry. Calcium hypochlorite [Ca(ClO)2, bleaching powder] is also used as a bleaching agent and disinfectant.