A The Scope of Pharmacology 藥理學范疇

A The Scope of Pharmacology

藥理學范疇

In its entirety, pharmacology embraces the knowledge of the history, source, physical and chemical properties, compounding, biochemical and physiological effects, mechanisms of action, absorption, distribution, biotransformation and excretion, and therapeutic and other uses of drugs. Since a drug is broadly defined as any chemical agent that affects living processes, the subject of pharmacology is obviously quite extensive.

總體來說，藥理學包括藥物的以下諸方面內(nèi)容:歷史背景、來源、理化特性、合成、生化生理作用、作用機制、吸收、分布、生物轉(zhuǎn)化和排泄以及治療作用和其他作用。由于藥物被一般性定義為影響生命過程的化學物質(zhì)，因而藥理學范疇顯然是極其廣泛的。

For the physician and the medical student, however, the scope of pharmacology is less expansive than indicated by the above definitions. The clinician is interested primarily in drugs that are useful in the prevention, diagnosis, and treatment of human disease, or in the prevention of pregnancy. His study of the pharmacology of these drugs can be reasonably limited to those aspects that provide the basis for their rational clinical use. Secondarily, the physician is also concerned with chemical agents that are not used in therapy but are commonly responsible for household and industrial poisoning as well as environmental pollution. His study of these substances is justifiably restricted to the general principles of prevention, recognition, and treatment of such toxicity or pollution. Finally, all physicians share in the responsibility to help resolve the continuing sociological problem of the abuse of drugs.

然而，就醫(yī)生和醫(yī)學生生而言，藥理學范疇并沒有上述定義那么廣泛。臨床醫(yī)生的主要興趣在于藥物對人類疾病的預防、診斷及治療.或是在避孕方而所起的作用。因而他對這些藥物的藥理學研究不僅僅周限于某些方面，只要能為其合理的臨床用藥提供理論根據(jù)就行。其次，醫(yī)生也關注某些化學物質(zhì)，這些物質(zhì)雖然不用于治療，但通常與家庭中毒;工業(yè)中毒以及環(huán)境污染有關。醫(yī)生對這些物質(zhì)的研究當然僅限于一般性了解。對這類中毒或汚污染的防范、診斷和治療。最后，所有醫(yī)生都應責無旁貸地為解決藥品濫用所引起的社會問題而做出自己的努力。

A brief consideration of its major subject areas will further clarify how the study of pharmacology is best approached from the standpoint of the specific requirements and interests of the medical student and practitioner. At one time, it was essential for the physician to have a broad botanical knowledge, since he had to select the proper plants from which to prepare his own crude medicinal preparations. However, fewer drugs are now obtained from natural sources, and, more importantly, most of these are highly purified or standardized and differ little from synthetic chemicals. Hence, the interests of the clinician in pharmacognosy are correspondingly limited. Nevertheless, scientific curiosity should stimulate the physician to learn something of the sources of drugs, and this knowledge often proves practically useful as well as interesting. He will find the history of drugs of similar value.

從醫(yī)學生和從業(yè)醫(yī)師的特別耑求和一般興趣的角度來看，什么才是藥理學學習的最佳途徑呢?只要對其主要學科領域稍加研究便可知曉。以前，醫(yī)師必須擁有廣泛的植物方而的知識，因為他得挑選適當?shù)闹参?，且將其制備成簡單的藥物制劑。然而，現(xiàn)在的藥物已很少取自于天然植物，而且更為重要的是大多數(shù)天然藥物已被高度提純，且與合成的化學藥物無甚區(qū)別，所以，臨床醫(yī)生對生藥學的興趣也相應減弱。盡管如此，應該激勵臨床醫(yī)生了解藥物的來源的科學好奇心，這方面知識往往被證明不但有趣，而且有用。他將會發(fā)現(xiàn)了解藥物的歷史同樣具有價值。

The preparing, compounding, and dispensing of medicines at one time lay within the province of the physician, but this work is now delegated almost completely to the pharmacist1. However, to write intelligent prescription orders, the physician must have some knowledge of the physical and chemical properties of drugs and their available dosage forms, and he must have a basic familiarity with the practice of pharmacy. When the physician shirks his responsibility in this regard, he invariably fails to translate his knowledge of pharmacology and medicine into prescription orders and medication best suited for the individual patient.

藥物的制備、合成與銷售一度都是醫(yī)生的職責，但這項工作現(xiàn)在幾乎全歸藥師了。不過臨床醫(yī)師要想開出合理的處方，必須對藥物的理化性質(zhì)及其現(xiàn)有劑型有所了解,必須基本了解藥房業(yè)務。若臨床醫(yī)師逃避這方面責任，他肯定用不好藥理學及藥物知識，從而難以開出適合每位患者的最佳醫(yī)療處方。 I

Pharmacokinetics deals with the absorption, distribution, biotransformation, and excretion of drugs. These factors, coupled with dosage, determine the concentration of a drug at its sites of action and, hence, the intensity of its effects as a function of time. Many basic principles of biochemistry and enzymology and the physical and chemical principles that govern the active and passive transfer and the distribution of substances across biological membranes are readily applied to the understanding of this important aspect of pharmacology2.

藥物動力學涉及藥物的吸收、分布、生物轉(zhuǎn)化以及排泄等方面。這些因素再加上劑量便決定了藥物在其作用點的濃度，進而決定了其與時間成函數(shù)關系的藥效強度。在對藥理學這一重要方面的理解過程中，常常運用到許多有關生物化學和酶學方面的基本原理和物理化學方面的一些基本法則，而這些原理和法則決定著物質(zhì)在生物膜之間的主動和被動轉(zhuǎn)移及分布。

The study of the biochemical and physiological effects of drugs and their mechanisms of action is termed as pharmacodynamics. It is an experimental medical science that dates back only to the later half of the nineteenth century. As a border science, pharmacodynamics borrows freely from both the subject matter and the experimental techniques of physiology, biochemistry, microbiology, immunology, genetics, and pathology. It is unique mainly in that attention is focused on the characteristics of drugs. As the name implies, the subject is a dynamic one. The student who attempts merely to memorize the pharmacodynamic properties of drugs is foregoing one of the best opportunities for correlating the entire field of preclinical medicine. For example, the actions and effects of the saluretic agents can be fully understood only in terms of the basic principles of renal physiology and of the pathogenesis of edema. Conversely, no greater insight into normal and abnormal renal physiology can be gained than by the study of the pharmacodynamics of the saluretic agents.

對藥物的生化生理作用及其作用機制的研究稱為藥效學。這是一門實驗醫(yī)學，其歷史僅可追溯到19世紀后半葉。作為邊緣學科，藥效學從生理學、生化學、微生物學、免疫學、遺傳學和病理學等諸多學科的主要理論和實驗技術中吸取了大量內(nèi)容。該學科的獨到之處主要在于其關注的要點是藥物的特征。顧名思義，該科目屬于動態(tài)學科。學生如果僅僅打算死記硬背藥物的藥效學特性的話，那他將會喪失把整個臨床前期醫(yī)學連為—體的這一最佳機會。例如:利鹽排泄劑的活性和效用只有在腎臟生理學和水腫發(fā)病機制的基本原理的基礎上才能完全理解。換句話說，只有通過對利鹽排泄劑的藥效學研究，才能最深人地了解腎臟生理學正常和異常兩方面情況。

Another ramification of pharmacodynamics is the correlation of the actions and effects of drugs with their chemical structures. Such structure-activity relationships are an integral link in the analysis of drug action, and exploitation of these relationships among established therapeutic agents has often led to the development of better drugs. However, the correlation of biological activity with chemical structure is usually of interest to the physician only when it provides the basis for summarizing other pharmacological information.

藥效學的另一分支是研究藥物活性和效用與其化學結(jié)構(gòu)的相互關系。這種構(gòu)效關系是分析藥物作用不可或缺的部分，將這種關系應用于現(xiàn)有的治療藥物中往往會促使藥品的更新?lián)Q代。然而，只有當生物活性與化學結(jié)構(gòu)的關聯(lián)能夠為總結(jié)其他藥物學信息提供基礎時，臨床醫(yī)師才會對此產(chǎn)生興趣。

The physician is understandably interested mainly in the effects of drugs in man. This emphasis on clinical pharmacology is justified, since the effects of drugs are often characterized by significant interspecies variation, and since they may be further modified by disease. In addition, some drug effects, such as those on mood and behavior, can be adequately studied only in man. However, the pharmacological evaluation of drugs in man may be limited for technical, legal, and ethical reasons, and the choice of drugs must be based in part on their pharmacological evaluation in animals. Consequently, some knowledge of animal pharmacology and comparative pharmacology is helpful in deciding the extent to which claims for a drug based upon studies in animals can be reasonably extrapolated to man3.

臨床醫(yī)師的興趣主要集中于藥物對人體的療效。臨床藥理重視這一點是合理的，因為藥物的作用往往因種屬的明顯差異而大相徑庭，并可能由于疾病的作用而發(fā)生進一步改而且有些藥物作用——諸如對情緒和行為的作用—只有通過人體才能得以充分研究，不過藥物對人體的藥理學評價可能因技術、法律及倫理道德方面的原因而受到限制，對藥物的選擇在一定程度上也只得以它們在動物身上所進行的藥理學評價為基礎。因此，動物藥理學和比較藥理學方面的知識有助于確定以動物實驗為基礎的某種新藥研制何時才可用于人體。

Pharmacotherapeutics deals with the use of drugs in the prevention and treatment of disease. Many drugs stimulate or depress biochemical or physiological function in man in a sufficiently reproducible manner to provide relief of symptoms or, ideally, to alter favorably the course of disease. Conversely, chemicotherapeutic agents are useful in therapy because they have only minimal effects on man but can destroy or eliminate parasites. Whether a drug is useful for therapy is crucially dependent upon its ability to produce its desired effects with only tolerable undesired effects. Thus, from the standpoint of the physician interested in the therapeutic uses of a drug, the selectivity of its effects is one of its most important characteristics. Drug therapy is rationally based upon the correlation of the actions and effects of drugs with the physiological, biochemical, microbiological, immunological, and behavioral aspects of disease. Pharmacodynamics provides one of the best opportunities for this correlation during the study of both the preclinical and the clinical medical sciences.

藥物治療學涉及如何在疾病防治中使用藥物。許多藥物以強有力的可重現(xiàn)方式促進或抑制著人體的生理生化功能，進而使癥狀得以緩解或促使病程朝著令人滿意的方向轉(zhuǎn)變。相反，化療藥物的治病功能是因為其對人體作用很小但卻能殺死或清除寄生生物。—種藥物是否可以用于治療，關鍵取決于其能否產(chǎn)生預期的治療效果，同時其副作用在可容忍的范圍內(nèi)。這樣，從關注藥物療效的臨床醫(yī)師的觀點來看，藥物作用的選擇性便是其最重要特點之一。藥物的活性和療效與疾病諸方面——生理、生化、微生物、免疫和行為——的聯(lián)系理所當然地成為藥物治療的基礎。藥效學便為臨床前期和臨床期醫(yī)學研究這種聯(lián)系提供了一個絕好的機會。

Toxicology is that aspect of pharmacology that deals with the adverse effects of drugs. It is concerned not only with drugs used in therapy but also with the many other chemicals that may be responsible for household, environmental, or industrial intoxication. The adverse effects of the pharmacological agents employed in therapy are properly considered an integral part of their total pharmacology. The toxic effects of other chemicals are such an extensive subject that the physician must usually confine his attention to the general principles applicable to the prevention, recognition, and treatment of drug poisonings of any cause.

毒理學是研究藥物副作用的藥理學分支。它不僅涉及治療藥物，還涉及引起家庭、環(huán)境或工業(yè)中毒的許多其他化學物質(zhì)。治療性藥物的副作用應被視為整個藥理學的一個組成部分。其他化學物質(zhì)的毒副作用范圍太廣，臨床醫(yī)師通常只能將注意力放在預防、確認和處理各種藥物中毒的基本原則上。

醫(yī)學英語