Amedication (also calledmedicament,medicine,pharmaceutical drug,medicinal product,medicinal drug or simplydrug) is adrug used todiagnose,cure, treat, orprevent disease.[1][2] Drug therapy (pharmacotherapy) is an important part of themedical field and relies on the science ofpharmacology for continual advancement and onpharmacy for appropriate management.
Drug discovery anddrug development are complex and expensive endeavors undertaken bypharmaceutical companies, academic scientists, and governments. As a result of this complex path from discovery to commercialization, partnering has become a standard practice for advancing drug candidates through development pipelines. Governments generally regulate what drugs can be marketed,how drugs are marketed, and in some jurisdictions,drug pricing. Controversies have arisen over drug pricing and disposal of used medications.
In Europe, the term is "medicinal product", and it is defined by EU law as:
"Any substance or combination of substances presented as having properties for treating or preventing disease in human beings; or"
"Any substance or combination of substances which may be used in or administered to human beings either with a view to restoring, correcting, or modifying physiological functions by exerting apharmacological,immunological or metabolic action or to making amedical diagnosis."[5]: 36
In the US, a "drug" is:
A substance (other than food) intended to affect the structure or any function of the body.
A substance intended for use as a component of a medicine but not a device or a component, part, or accessory of a device.
Biological products are included within this definition and are generally covered by the same laws and regulations, but differences exist regarding their manufacturing processes (chemical process versus biological process).[6]
Drug use among elderly Americans has been studied; in a group of 2,377 people with an average age of 71 surveyed between 2005 and 2006, 84% took at least one prescription drug, 44% took at least oneover-the-counter (OTC) drug, and 52% took at least onedietary supplement; in a group of 2245 elderly Americans (average age of 71) surveyed over the period 2010 – 2011, those percentages were 88%, 38%, and 64%.[7]
Pharmaceuticals may also be described as "specialty", independent of other classifications, which is an ill-defined class of drugs that might be difficult to administer, require special handling during administration, require patient monitoring during and immediately after administration, have particular regulatory requirements restricting their use, and are generally expensive relative to other drugs.[9]
A euthanaticum is used foreuthanasia andphysician-assisted suicide. Euthanasia is not permitted by law in many countries, and consequently, medicines will not be licensed for this use in those countries.
Oral administration, the most common form of enteral administration, can be performed using variousdosage forms includingtablets orcapsules and liquid such as syrup or suspension. Other ways to take the medication includebuccally (placed inside the cheek),sublingually (placed underneath the tongue), eye andear drops (dropped into the eye or ear), and transdermally (applied to the skin).[11]
They can be administered in one dose, as abolus. Administration frequencies[12] are often abbreviated from Latin, such asevery 8 hours reading Q8H fromQuaque VIII Hora. The drug frequencies are often expressed as the number of times a drug is used per day (e.g., four times a day). It[specify] may include event-related information (e.g., 1 hour before meals, in the morning, at bedtime), or complimentary to an interval, although equivalent expressions may have different implications (e.g., every 8 hours versus 3 times a day).[citation needed]
Historically, drugs were discovered by identifying the active ingredient from traditional remedies or byserendipitous discovery. Laterchemical libraries of syntheticsmall molecules,natural products, orextracts were screened in intact cells or whole organisms to identify substances that have a desirable therapeutic effect in a process known asclassical pharmacology. Sincesequencing of thehuman genome which allowed rapid cloning and synthesis of large quantities of purified proteins, it has become common practice to usehigh throughput screening of large compound libraries against isolatedbiological targets which are hypothesized to bedisease-modifying in a process known asreverse pharmacology. Hits from these screens are then tested in cells and then in animals forefficacy. Even more recently, scientists have been able to understand the shape of biological molecules at the atomic level and to use that knowledge to design (seedrug design) drug candidates.[citation needed]
Despite advances in technology and understanding of biological systems, drug discovery is still a lengthy, "expensive, difficult, and inefficient process" with a low rate of new therapeutic discovery.[13] In 2010, the research and development cost of eachnew molecular entity (NME) was approximately US$1.8 billion.[14] Drug discovery is done by pharmaceutical companies, sometimes with research assistance from universities. The "final product" of drug discovery is a patent on the potential drug. The drug requires very expensive Phase I, II, and III clinical trials, and most of them fail. Small companies have a critical role, often then selling the rights to larger companies that have the resources to run the clinical trials.
Drug discovery is different from Drug Development. Drug Discovery is often considered the process of identifying new medicine. At the same time, Drug development is delivering a new drug molecule into clinical practice. In its broad definition, this encompasses all steps from the basic research process of finding a suitable molecular target to supporting the drug's commercial launch.
Drug development is the process of bringing a new drug to the market once alead compound has been identified through the process ofdrug discovery. It includes pre-clinical research (microorganisms/animals) andclinical trials (on humans) and may include the step of obtaining regulatory approval to market the drug.[15][16]
Discovery: The Drug Development process starts with Discovery, a process of identifying a new medicine.
Development: Chemicals extracted from natural products are used to make pills, capsules, or syrups for oral use. Injections for direct infusion into the blood drops for eyes or ears.
Preclinical research: Drugs go under laboratory or animal testing, to ensure that they can be used on Humans.
Clinical testing: The drug is used on people to confirm that it is safe to use.
FDAReview: drug is sent to FDA before launching the drug into the market.
FDA post-Market Review: The drug is reviewed and monitored by FDA for the safety once it is available to the public.
The regulation of drugs varies by jurisdiction. In some countries, such as the United States, they are regulated at the national level by a single agency. In other jurisdictions, they are regulated at the state level, or at both state and national levels by various bodies, as is the case in Australia. The role of therapeutic goods regulation is designed mainly to protect the health and safety of the population. Regulation is aimed at ensuring the safety, quality, and efficacy of the therapeutic goods which are covered under the scope of the regulation. In most jurisdictions, therapeutic goods must be registered before they are allowed to be marketed. There is usually some degree of restriction on the availability of certain therapeutic goods depending on their risk to consumers.[citation needed]
Depending upon thejurisdiction, drugs may be divided intoover-the-counter drugs (OTC) which may be available without special restrictions, andprescription drugs, which must beprescribed by a licensed medical practitioner in accordance withmedical guidelines due to the risk of adverse effects andcontraindications. The precise distinction between OTC and prescription depends on the legal jurisdiction. A third category, "behind-the-counter" drugs, is implemented in some jurisdictions. These do not require a prescription, but must be kept in thedispensary, not visible to the public, and be sold only by a pharmacist orpharmacy technician. Doctors may also prescribe prescription drugs foroff-label use – purposes which the drugs were not originally approved for by the regulatory agency. TheClassification of Pharmaco-Therapeutic Referrals helps guide the referral process between pharmacists and doctors.
TheInternational Narcotics Control Board of the United Nations imposes a world law ofprohibition of certain drugs. They publish a lengthy list of chemicals and plants whose trade and consumption (where applicable) are forbidden. OTC drugs are sold without restriction as they are considered safe enough that most people will not hurt themselves accidentally by taking it as instructed.[17] Many countries, such as the United Kingdom have a third category of "pharmacy medicines", which can be sold only in registeredpharmacies by or under the supervision of a pharmacist.
Medical errors include over-prescription andpolypharmacy, mis-prescription, contraindication and lack of detail in dosage and administration instructions. In 2000 the definition of a prescription error was studied using aDelphi method conference; the conference was motivated by ambiguity in what a prescription error is and a need to use a uniform definition in studies.[18]
In the UK, the Pharmaceutical Price Regulation Scheme is intended to ensure that theNational Health Service is able to purchase drugs at reasonable prices. The prices are negotiated between the Department of Health, acting with the authority of Northern Ireland and the UK Government, and the representatives of the Pharmaceutical industry brands, theAssociation of the British Pharmaceutical Industry (ABPI). For 2017 this payment percentage set by the PPRS will be 4,75%.[19]
In Canada, the Patented Medicine Prices Review Board examines drug pricing and determines if a price is excessive or not. In these circumstances, drug manufacturers must submit a proposed price to the appropriate regulatory agency. Furthermore, "the International Therapeutic Class Comparison Test is responsible for comparing the National Average Transaction Price of the patented drug product under review"[20] different countries that the prices are being compared to are the following: France, Germany, Italy, Sweden, Switzerland, the United Kingdom, and the United States[20]
In the United States, drug costs are partially unregulated, but instead are the result of negotiations between drug companies and insurance companies.[22]
High prices have been attributed to monopolies given to manufacturers by the government.[23] New drug development costs continue to rise as well. Despite the enormous advances in science and technology, the number of new blockbuster drugs approved by the government per billion dollars spent has halved every 9 years since 1950.[24]
A blockbuster drug is a drug that generates more than $1 billion in revenue for a pharmaceutical company in a single year.[25]Cimetidine was the first drug ever to reach more than $1 billion a year in sales, thus making it the first blockbuster drug.[26]
In the pharmaceutical industry, a blockbuster drug is one that achieves acceptance by prescribing physicians as a therapeutic standard for, most commonly, a highly prevalent chronic (rather than acute) condition. Patients often take the medicines for long periods.[27]
Antibiotics first arrived on the medical scene in 1932 thanks toGerhard Domagk;[28] and were coined the "wonder drugs". The introduction of thesulfa drugs led to the mortality rate frompneumonia in the U.S. to drop from 0.2% each year to 0.05% (i.e.,1⁄4 as much) by 1939.[29] Antibiotics inhibit the growth or the metabolic activities of bacteria and other microorganisms by a chemical substance of microbial origin.Penicillin, introduced a few years later, provided a broader spectrum of activity compared to sulfa drugs and reduced side effects.Streptomycin, found in 1942, proved to be the first drug effective against the cause oftuberculosis and also came to be the best known of a long series of important antibiotics. A second generation of antibiotics was introduced in the 1940s:aureomycin andchloramphenicol. Aureomycin was the best known of the second generation.[citation needed]
Lithium was discovered in the 19th century for nervous disorders and its possible mood-stabilizing or prophylactic effect; it was cheap and easily produced. As lithium fell out of favor in France,valpromide came into play. This antibiotic was the origin of the drug that eventually created the mood stabilizer category. Valpromide had distinct psychotrophic effects that were of benefit in both the treatment of acute manic states and in the maintenance treatment of manic depression illness.Psychotropics can either besedative orstimulant; sedatives aim at damping down the extremes of behavior. Stimulants aim at restoring normality by increasing tone. Soon arose the notion of a tranquilizer which was quite different from any sedative or stimulant. The term tranquilizer took over the notions of sedatives and became the dominant term in the West through the 1980s. In Japan, during this time, the term tranquilizer produced the notion of a psyche-stabilizer and the term mood stabilizer vanished.[30]
Premarin (conjugated estrogens, introduced in 1942) andPrempro (a combination estrogen-progestin pill, introduced in 1995) dominated thehormone replacement therapy (HRT) during the 1990s. HRT is not a life-saving drug, nor does it cure any disease. HRT has been prescribed to improve one's quality of life. Doctors prescribe estrogen for their older female patients both to treat short-term menopausal symptoms and to prevent long-term diseases. In the 1960s and early 1970s, more and more physicians began to prescribe estrogen for their female patients. Between 1991 and 1999, Premarin was listed as the most popular prescription and best-selling drug in America.[30]
The first oral contraceptive,Enovid, was approved by FDA in 1960. Oral contraceptives inhibit ovulation and so prevent conception. Enovid was known to be much more effective than alternatives including the condom and the diaphragm. As early as 1960, oral contraceptives were available in several different strengths by every manufacturer. In the 1980s and 1990s, an increasing number of options arose including, most recently, a newdelivery system for the oral contraceptive via atransdermal patch. In 1982, a new version of"the pill" was introduced, known as thebiphasic pill. By 1985, a newtriphasic pill was approved. Physicians began to think of "the pill" as an excellent means of birth control for young women.[30]
Stimulants such asRitalin (methylphenidate) came to be pervasive tools for behavior management and modification in young children. Ritalin was first marketed in 1955 fornarcolepsy; its potential users were middle-aged and the elderly. It was not until some time in the 1980s along with hyperactivity in children that Ritalin came onto the market. Medical use of methylphenidate is predominantly for symptoms ofattention deficit hyperactivity disorder (ADHD). Consumption of methylphenidate in the U.S. out-paced all other countries between 1991 and 1999. Significant growth in consumption was also evident in Canada, New Zealand, Australia, and Norway. Currently, 85% of the world's methylphenidate is consumed in America.[30]
The first minor tranquilizer wasmeprobamate. Only fourteen months after it was made available, meprobamate had become the country's largest-selling prescription drug. By 1957, meprobamate had become the fastest-growing drug in history. The popularity of meprobamate paved the way forLibrium andValium, two minor tranquilizers that belonged to a new chemical class of drugs called thebenzodiazepines. These were drugs that worked chiefly asanti-anxiety agents andmuscle relaxants. The first benzodiazepine was Librium. Three months after it was approved, Librium had become the most prescribed tranquilizer in the nation. Three years later, Valium hit the shelves and was ten times more effective as a muscle relaxant and anti-convulsant. Valium was the most versatile of the minor tranquilizers. Later came the widespread adoption of major tranquilizers such aschlorpromazine and the drugreserpine. In 1970, sales began to decline for Valium and Librium, but sales of new and improved tranquilizers, such asXanax, introduced in 1981 for the newly created diagnosis of panic disorder, soared.[30]
Mevacor (lovastatin) is the first and most influentialstatin in the American market. The 1991 launch ofPravachol (pravastatin), the second available in the United States, and the release ofZocor (simvastatin) made Mevacor no longer the only statin on the market.In 1998,Viagra was released as a treatment for erectile dysfunction.[30]
Using plants and plant substances to treat all kinds of diseases and medical conditions is believed to date back toprehistoric medicine.[citation needed]
On the Indian subcontinent, theAtharvaveda, a sacred text ofHinduism whose core dates from the second millennium BC, although the hymns recorded in it are believed to be older, is the first Indic text dealing with medicine. It describes plant-based drugs to counter diseases.[34] The earliest foundations ofayurveda were built on a synthesis of selected ancient herbal practices, together with a massive addition of theoretical conceptualizations, newnosologies and new therapies dating from about 400 BC onwards.[35] The student of Āyurveda was expected to know ten arts that were indispensable in the preparation and application of his medicines: distillation, operative skills, cooking, horticulture, metallurgy, sugar manufacture, pharmacy, analysis and separation of minerals, compounding of metals, and preparation ofalkalis.
Medieval medicine of Western Europe saw advances in surgery compared to previously, but few truly effective drugs existed, beyondopium (found in such extremely popular drugs as the "Great Rest" of theAntidotarium Nicolai at the time)[38] andquinine. Folklore cures and potentially poisonous metal-based compounds were popular treatments.Theodoric Borgognoni, (1205–1296), one of the most significant surgeons of the medieval period, responsible for introducing and promoting important surgical advances including basicantiseptic practice and the use ofanaesthetics.Garcia de Orta described some herbal treatments that were used.[vague]
For most of the 19th century, drugs were not highly effective, leadingOliver Wendell Holmes Sr. to famously comment in 1842 that "if all medicines in the world were thrown into the sea, it would be all the better for mankind and all the worse for the fishes".[27]: 21
In the inter-war period, the first anti-bacterial agents such as thesulpha antibiotics were developed. The Second World War saw the introduction of widespread and effective antimicrobial therapy with the development and mass production ofpenicillin antibiotics, made possible by the pressures of the war and the collaboration of British scientists with the Americanpharmaceutical industry.
Medicines commonly used by the late 1920s includedaspirin,codeine, andmorphine for pain;digitalis,nitroglycerin, andquinine for heart disorders, andinsulin for diabetes. Other drugs includedantitoxins, a few biological vaccines, and a few synthetic drugs. In the 1930s, antibiotics emerged: firstsulfa drugs, thenpenicillin and other antibiotics. Drugs increasingly became "the center of medical practice".[27]: 22 In the 1950s, other drugs emerged includingcorticosteroids forinflammation,rauvolfia alkaloids as tranquilizers and antihypertensives,antihistamines for nasal allergies,xanthines for asthma, and typicalantipsychotics for psychosis.[27]: 23–24 As of 2007, thousands of approved drugs have beendeveloped. Increasingly,biotechnology is used to discoverbiopharmaceuticals.[27] Recently, multi-disciplinary approaches have yielded a wealth of new data on the development of novel antibiotics and antibacterials and on the use of biological agents for antibacterial therapy.[39]
In the 1950s, new psychiatric drugs, notably the antipsychoticchlorpromazine, were designed in laboratories and slowly came into preferred use. Although often accepted as an advance in some ways, there was some opposition, due to serious adverse effects such astardive dyskinesia. Patients often opposed psychiatry and refused or stopped taking the drugs when not subject to psychiatric control.
Governments have been heavily involved in the regulation of drug development and drug sales. In the U.S., theElixir Sulfanilamide disaster led to the establishment of theFood and Drug Administration, and the 1938 Federal Food, Drug, and Cosmetic Act required manufacturers to file new drugs with the FDA. The 1951 Humphrey-Durham Amendment required certain drugs to be sold by prescription. In 1962, a subsequent amendment required new drugs to be tested for efficacy and safety inclinical trials.[27]: 24–26
Until the 1970s, drug prices were not a major concern for doctors and patients. As more drugs became prescribed for chronic illnesses, however, costs became burdensome, and by the 1970s nearly every U.S. state required or encouraged the substitution ofgeneric drugs for higher-priced brand names. This also led to the 2006 U.S. law,Medicare Part D, which offers Medicare coverage for drugs.[27]: 28–29
As of 2008, the United States is the leader inmedical research, including pharmaceutical development. U.S. drug prices are among the highest in the world, and drug innovation is correspondingly high. In 2000, U.S.-based firms developed 29 of the 75 top-selling drugs; firms from the second-largest market, Japan, developed eight, and the United Kingdom contributed 10. France, which imposes price controls, developed three. Throughout the 1990s, outcomes were similar.[27]: 30–31
Controversies concerning pharmaceutical drugs include patient access to drugs under development and not yet approved, pricing, and environmental issues.
Governments worldwide have created provisions for granting access to drugs prior to approval for patients who have exhausted all alternative treatment options and do not match clinical trial entry criteria. Often grouped under the labels of compassionate use,expanded access, or named patient supply, these programs are governed by rules which vary by country defining access criteria, data collection, promotion, and control of drug distribution.[40]
Within the United States, pre-approval demand is generally met throughtreatment IND (investigational new drug) applications (INDs), or single-patient INDs. These mechanisms, which fall under the label of expanded access programs, provide access to drugs for groups of patients or individuals residing in the US. Outside the US, Named Patient Programs provide controlled, pre-approval access to drugs in response to requests by physicians on behalf of specific, or "named", patients before those medicines are licensed in the patient's home country. Through these programs, patients are able to access drugs in late-stage clinical trials or approved in other countries for a genuine, unmet medical need, before those drugs have been licensed in the patient's home country.[citation needed]
Patients who have not been able to get access to drugs in development have organized and advocated for greater access. In the United States,ACT UP formed in the 1980s, and eventually formed itsTreatment Action Group in part to pressure the US government to put more resources into discovering treatments for AIDS and then to speed release of drugs that were under development.[41]
TheAbigail Alliance was established in November 2001 by Frank Burroughs in memory of his daughter, Abigail.[42] The Alliance seeks broader availability of investigational drugs on behalf of terminally ill patients.
In 2013,BioMarin Pharmaceutical was at the center of a high-profile debate regarding expanded access of cancer patients to experimental drugs.[43][44]
Essential medicines, as defined by theWorld Health Organization (WHO), are "those drugs that satisfy the health care needs of the majority of the population; they should therefore be available at all times in adequate amounts and in appropriate dosage forms, at a price the community can afford."[45] Recent studies have found that most of the medicines on the WHO essential medicines list, outside of the field of HIV drugs, are not patented in the developing world, and that lack of widespreadaccess to these medicines arise from issues fundamental to economic development – lack of infrastructure and poverty.[46]Médecins Sans Frontières also runs aCampaign for Access to Essential Medicines campaign, which includes advocacy for greater resources to be devoted to currently untreatable diseases that primarily occur in the developing world. TheAccess to Medicine Index tracks how well pharmaceutical companies make their products available in the developing world.[citation needed]
World Trade Organization negotiations in the 1990s, including theTRIPS Agreement and theDoha Declaration, have centered on issues at the intersection of international trade in pharmaceuticals andintellectual property rights, with developed world nations seeking strong intellectual property rights to protect investments made to develop new drugs, and developing world nations seeking to promote their generic pharmaceuticals industries and their ability to make medicine available to their people viacompulsory licenses.
Some have raised ethical objections specifically with respect to pharmaceutical patents and the high prices for drugs that they enable their proprietors to charge, which poor people around the world, cannot afford.[47][48] Critics also question the rationale that exclusive patent rights and the resulting high prices are required for pharmaceutical companies to recoup the large investments needed for research and development.[47] One study concluded that marketing expenditures for new drugs often doubled the amount that was allocated for research and development.[49] Other critics claim that patent settlements would be costly for consumers, the health care system, and state and federal governments because it would result in delaying access to lower cost generic medicines.[50]
Novartis fought a protracted battle with the government of India over the patenting of its drug,Gleevec, in India, which ended up in a Supreme Court in a case known asNovartis v. Union of India & Others. The Supreme Court ruled narrowly against Novartis, but opponents of patenting drugs claimed it as a major victory.[51]
Scientists generally divide environmental impacts of a chemical into three primary categories: persistence,bioaccumulation, andtoxicity.[53] Since medications are inherently bio-active, most are naturally degradable in the environment, however they are classified as "pseudopersistent" because they are constantly being replenished from their sources.[52] TheseEnvironmentally Persistent Pharmaceutical Pollutants (EPPPs) rarely reach toxic concentrations in the environment, however they have been known to bioaccumulate in some species.[58] Their effects have been observed to compound gradually acrossfood webs, rather than becoming acute, leading to their classification by theUS Geological Survey as "Ecological Disrupting Compounds."[52]
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