Here’s one that I hear a lot: “We’re the richest country in the world, yet we don’t provide health care for all of our citizens. That’s unconscionable!”

Embedded in the “That’s unconscionable!” part of the argument is an implicit statement that health care is a right. But a right for whom? For Americans? Why Americans? Why not Mauritanians, Serbians, Cambodians, and so on and so forth? If “health care is a right” is taken to its logical Read more

Development plans for new drugs should include screening for potential drug interactions at an early stage. Structural chemistry and other chemical properties will give a broad idea of how the drug may be absorbed, transported, metabolized and excreted. Mechanistic studies to elucidate the mechanism of action will give indications for possible interactions with other drugs acting at the same site. In vitro and in vivo investigations on hepatic enzyme systems can be carried out to investigate the substrate potential and/or capability for inhibition or induction of liver enzyme systems; this information can then be used to guide investigations of metabolic interactions that may be of eventual clinical significance. The animal toxicokinetics may also provide information about what can be expected in humans. Read more

Most of these drug interactions involve displacement of drug from plasma proteins, thus increasing the free/bound ratio for drug concentration. When the free moieties are those that are pharmacologically active, then unexpectedly exaggerated responses result from standard doses. Most (but not all) such interactions are unwanted. Almost any nonsteroidal anti-inflammatory drug (NSAID) displaces warfarin, thus enhancing its anticoagulant effect and rendering the patient liable to unexpected ecchymosis or more serious hemorrhagic adverse events. Similarly unwanted are the interactions between phenytoin and thyroxine (sedation and thyrotoxicosis), and salicylates with tolbutamide (hypoglycemia). Oral contraceptives compete for albumin-binding sites, and phenytoin doses may need to be adjusted when the former are introduced. A rare example of a beneficial drug interaction at this locus are the use of NSAIDs with some glucocorticoids, where enhanced anti-inflammatory effects of the latter can result, even though a relatively low dose has been administered. Read more

In recent years, the role of over-the-counter (OTC)
medication in the overall health system has
increased dramatically. The increased interest in
and availability of OTC medications is being driven
by several factors: Read more

Chapter overview
If a drug is to have a therapeutic effect on the body, it first has to reach its site of action. In order to do this a drug has to be administered in some way. Unless the route of administration is directly into the blood stream, the drug has to be absorbed, usually by diffusion. Once absorbed, distribution of the drug to different parts of the body follows. This necessarily includes passage through the liver. Most drugs are treated as potentially toxic substances and are metabolized by the liver. This detoxifies them and some drugs are almost totally inactivated on first pass through the liver. Eventually a drug will be excreted from the body. This usually occurs via the kidneys, although some drugs can be lost in faeces or exhaled air. This chapter discusses the processes of administration, absorption, distribution, metabolism and excretion of drugs together with factors affecting these processes. Collectively, these processes describe drug disposition, the way in which the body handles drugs. The study of the fate of drugs in the body is known as pharmacokinetics.
Administration of drugs
In order to get to their site of action in the body, drugs have to be administered in some way. There are two major routes of drug administration: enteral and parenteral. Enteral means to do with the gastrointestinal tract and includes oral and rectal administration. The parenteral route includes all other means of drug administration. There are many routes of parenteral administration, some of which are intended for a drug to have a systemic effect and others for a local effect. See Figure 2.1.
(In some definitions, parenteral is synonymous with injection (for example in the Medicines Act), but here the term is used to describe all routes of administration that are not enteral.)

All drugs have at least three names: the chemical name, the generic name and the proprietary name. Chemical names can be complicated and difficult to remember and are not used in this book. A generic name is a drug’s official name and the majority of drugs in this book are referred to by their generic names. The proprietary name is the name given to a drug by the manufacturing company. As the same drug can be manufactured by several different companies, a drug can have multiple proprietary names and this can be confusing. Hence, proprietary names have been avoided in this book except where the proprietary name is in common usage. In the United Kingdom, the generic name is known as the British approved name (BAN ). Read more

Patient compliance is important for successful drug therapy. Compliance in this context is defined as the extent to which the patient follows the clinical prescription. Non-compliance and reasons why patients do not always take drugs as prescribed should be appreciated. Some common reasons for non-compliance are that the patient has doubts about a drug’s effectiveness, they believe they are cured, they misunderstand instructions, dosage regimes are too complicated, or they experience unacceptable side effects. Health care professionals play an important role in improving compliance. This is particularly important if a drug is for serious conditions like epilepsy, glaucoma or hypertension, or is for infection because of the problem of drug resistance. Well-informed patients are more likely to be compliant. Read more

Pharmacology is the science of drugs and their effects on biological systems. A drug can be defined as a chemical that can cause a change in a biological system; the important biological system to be considered in this book is the human body. A drug is the active ingredient in a medicine; a medicine is the formulation of a drug into a tablet, capsule or other delivery system. The Medicines Act 1968 refers to drugs as medicinal products. Drugs can be naturally occurring substances, for example hormones; everyday substances, for example caffeine and alcohol; synthetic chemicals marketed for therapeutic activity, for example aspirin; or substances used for recreation. Read more