Medication - WikiHQ

thumb|An example of a medication is a [[prescription drug.]]

Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug, or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and relies on the science of pharmacology for continual advancement and on pharmacy for appropriate management.

Drugs are classified in many ways. One of the key divisions is by level of control, which distinguishes prescription drugs (those that a pharmacist dispenses only on the medical prescription) from over-the-counter drugs (those that consumers can order for themselves). Medicines may be classified by mode of action, route of administration, biological system affected, or therapeutic effects. The World Health Organization keeps a list of essential medicines.

Drug discovery and drug development are complex and expensive endeavors undertaken by pharmaceutical 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.

Definition

Medication is a medicine or a chemical compound used to treat or cure illness. According to Encyclopædia Britannica, medication is "a substance used in treating a disease or relieving pain".

As defined by the National Cancer Institute, dosage forms of medication can include tablets, capsules, liquids, creams, and patches. Medications can be administered in different ways, such as by mouth, by infusion into a vein, or by drops put into the ear or eye. A medication that does not contain an active ingredient and is used in research studies is called a placebo.

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 a pharmacological, immunological or metabolic action or to making a medical diagnosis."

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.
A substance intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease.
A substance recognized by an official pharmacopeia or formulary.
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).

Usage

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 one over-the-counter (OTC) drug, and 52% took at least one dietary 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%.

Classification

One of the key classifications is between traditional small molecule drugs; usually derived from chemical synthesis and biological medical products; which include recombinant proteins, vaccines, blood products used therapeutically (such as IVIG), gene therapy, and cell therapy (for instance, stem cell therapies).

Pharmaceuticals or drugs or medicines are classified into various other groups besides their origin on the basis of pharmacological properties like mode of action and their pharmacological action or activity, such as by chemical properties, mode or route of administration, biological system affected, or therapeutic effects. An elaborate and widely used classification system is the Anatomical Therapeutic Chemical Classification System (ATC system). The World Health Organization keeps a list of essential medicines.

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.

Classification By Function

Medicines may be classified by their therapeutic function—that is, the role they play in treating or preventing disease. The following table summarizes common categories of medications by their primary use:

{| class="wikitable"

!Type

!Definition

!Examples

|Analgesics

|Used to relieve pain

|Acetylsalicylic acid (ASA), acetaminophen (paracetamol), ibuprofen

|Antibiotics

|Used to kill or inhibit the growth of bacteria

|Penicillin, amoxicillin, ciprofloxacin

|Antifungals

|Used to kill or inhibit the growth of fungal pathogens

|Clotrimazole, fluconazole, metronidazole

|Antihistamines

|Used to reduce allergy symptoms

|Diphenhydramine, cetirizine, loratadine

|Antipyretics

|Used to reduce fever

|Acetylsalicylic acid (ASA), acetaminophen (paracetamol)

|Antivirals

|Used to kill or inhibit the growth of viral pathogens

|Acyclovir, ganciclovir, oseltamivir

|Anticoagulants

|Used to prevent blood clot formation

|Apixaban, heparin, enoxaparin

|Antidepressants

|Used to manage depression and related mental health conditions

|Sertraline, fluoxetine, bupropion

|Antineoplastics

|Used in the treatment of cancer

|Cyclophosphamide, etoposide

|Antipsychotics

|Used to manage severe mental health conditions (such as schizophrenia, treatment-resistant depression)

|Haloperidol, clozapine, aripiprazole

|Bronchodilators

|Used to open the airways in the lungs

|Albuterol, formoterol, tiotropium

|Corticosteroids

|Used to reduce inflammation throughout the body

|Dexamethasone, prednisone, triamcinolone

|Mood Stabilizers

|Used to treat bipolar disorder and other mood-related conditions

|Lithium, lamotrigine

|Statins

|Used to lower blood cholesterol levels

|Atorvastatin, rosuvastatin, pravastatin

|Antacids

|Neutralize stomach acid to relieve heartburn and indigestion

|Calcium carbonate, magnesium hydroxide

|Proton pump inhibitors (PPIs)

|Reduce stomach acid production by blocking proton pumps

|Omeprazole, pantoprazole, lansoprazole

|H2 receptor antagonists

|Reduce stomach acid by blocking histamine H2 receptors

|Famotidine, ranitidine (withdrawn in many countries)

|Antiemetics

|Used to prevent or treat nausea and vomiting

|Ondansetron, metoclopramide, promethazine

|Anticonvulsants

|Used to manage or prevent seizures

|Valproic acid, carbamazepine, oxcarbazepine

|Diuretics

|Promote urine production to reduce fluid overload and lower blood pressure

|Furosemide, hydrochlorothiazide, bumetanide

|Beta blockers

|Lower heart rate and blood pressure by blocking beta-adrenergic receptors

|Metoprolol, propranolol, atenolol

|Calcium channel blockers

|Relax blood vessels and reduce blood pressure

|Amlodipine, diltiazem, nicardipine, clevidipine

|ACE Inhibitors

|Lower blood pressure by inhibiting angiotensin-converting enzyme

|Enalapril, ramipril, lisinopril

|Antidiabetics

|Used to manage blood glucose levels in diabetes

|Metformin, insulin, gliclazide

|Thyroid hormones

|Replace or supplement thyroid hormone levels

|Levothyroxine, liothyronine,

|Hormonal contraceptives

|Prevent pregnancy by altering hormonal regulation

|ethinyl estradiol/norgestimate, levonorgestrel

|Sedatives / Hypnotics

|Induce or maintain sleep, reduce anxiety

|Zopiclone, alprazolam, zolpidem

|Stimulants

|Enhance alertness, attention, and energy

|Methylphenidate, amphetamine, caffeine

|Immunosuppressants

|Suppress immune response to prevent organ rejection or treat autoimmune disease

|Cyclosporine, tacrolimus, adalimumab

|Vaccines

|Stimulate the immune system to prevent infectious disease

|Influenza vaccine, MMR, COVID-19 mRNA vaccines

By Administration

Medicines can also be categorized based on how they are administered. The route of administration can affect the speed and effectiveness of treatment. Below is a summary of common routes:

{| class="wikitable"

!Type

!Definition

!Examples

! colspan="3" |Oral and Mucosal

|Oral

|Taken by mouth; the most common route of administration

|Tablets, capsules, syrups

|Sublingual

|Placed under the tongue for rapid absorption into the bloodstream

|Nitroglycerin, buprenorphine

|Buccal

|Placed between the gum and cheek; absorbed through oral mucosa

|Fentanyl, misoprostol

! colspan="3" |Local Application

|Topical

|Applied directly to the skin or mucous membranes to treat localized conditions

|Neosporin, mometasone ointment, clobetasol lotion

|Ophthalmic

|Applied to the eyes for local treatment

|Artificial tears, timolol eye drops

|Otic

|Applied into the ear canal for local treatment

|Antibiotic ear drops (combo ciprofloxacin with dexamethasone)

|Nasal

|Sprayed or instilled into the nose for local or systemic absorption

|Fluticasone nasal spray, naloxone nasal spray

|Suppositories

|Delivers medication via the rectum, vagina, or urethra, depending on formulation

|Rectal suppositories, vaginal pessaries

|Transdermal

|Delivers medication through the skin for systemic absorption, bypassing the digestive system

|Transdermal patches (e.g., fentanyl, nicotine), transdermal gels (e.g. estradiol, diclofenac)

! colspan="3" |Inhalation

|Inhalers

|Delivers medication directly to the lungs, most often used for respiratory conditions

|Salbutamol metered-dose inhalers (MDIs), Mometasone furoate dry powder Inhalers (DPIs)

|Nebulized

|Delivered as fine mist via nebuilizer especially for children or severe respiratory cases

|Hypertonic saline, ipratropium

! colspan="3" |Parenteral (injectable)

|Intramuscular

|Injected into a muscle, typically the deltoid or gluteus. Commonly used for vaccines and fast-acting medications

|Influenza vaccine, epinepherine

|Subcutaneous

|Injected into the fatty tissue beneath the skin. Commonly used for biologics, hormones, and insulin.

|Insulin, low-molecular-weight heparin

|Intravenous

|Injected directly into a vein for immediate systemic effect. Commonly used for emergency medications, fluids and chemotherapy

|Morphine, vancomycin, chemotherapy drugs

|Intradermal

|Injected into the dermis (just under the skin surface). Commonly used for allergy tests, tuberculosis screening

|Tuberculin (Mantoux test)

|Intrathecal

|Injected into the cerebrospinal fluid within the spinal canal. Commonly used for chemotherapy and spinal anesthesia.

|Methotrexate (for CNS cancers), bupivacaine

|Epidural

|Injected into the epidural space around the spinal cord. Commonly used for pain management, anesthesia during childbirth

|Fentanyl, bupivacaine

|Intraarticular

|Injected into a joint space. Commonly used for joint inflammation (e.g. arthritis)

|Triamcinolone, ketorolac, ropivacaine

|Intraosseous

|Injected directly into the bone marrow (emergency access when IV not possible). For emergency medicine in paediatrics and trauma

|Fluids, epinephrine via IO device

! colspan="3" |Other

|Implant

|Surgically placed or subdermal device that releases medication over time

|Contraceptive implants, insulin pumps, drug eluting stents

Drug discovery

In the fields of medicine, biotechnology, and pharmacology, drug discovery is the process by which new drugs are discovered.

Historically, drugs were discovered by identifying the active ingredient from traditional remedies or by serendipitous discovery. Later chemical libraries of synthetic small molecules, natural products, or extracts were screened in intact cells or whole organisms to identify substances that have a desirable therapeutic effect in a process known as classical pharmacology. Since sequencing of the human genome which allowed rapid cloning and synthesis of large quantities of purified proteins, it has become common practice to use high throughput screening of large compound libraries against isolated biological targets which are hypothesized to be disease-modifying in a process known as reverse pharmacology. Hits from these screens are then tested in cells and then in animals for efficacy. 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 (see drug design) drug candidates.

Modern drug discovery involves the identification of screening hits, medicinal chemistry, and optimization of those hits to increase the affinity, selectivity (to reduce the potential of side effects), efficacy/potency, metabolic stability (to increase the half-life), and oral bioavailability. Once a compound that fulfills all of these requirements has been identified, it will begin the process of drug development prior to clinical trials. One or more of these steps may, but not necessarily, involve computer-aided drug design.

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. In 2010, the research and development cost of each new molecular entity (NME) was approximately US$1.8 billion. 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.

Development

Drug development is the process of bringing a new drug to the market once a lead compound has been identified through the process of drug discovery. It includes pre-clinical research (microorganisms/animals) and clinical trials (on humans) and may include the step of obtaining regulatory approval to market the drug.

Drug Development Process

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.

FDA Review: 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.

Regulation

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.

Depending upon the jurisdiction, drugs may be divided into over-the-counter drugs (OTC) which may be available without special restrictions, and prescription drugs, which must be prescribed by a licensed medical practitioner in accordance with medical guidelines due to the risk of adverse effects and contraindications. 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 the dispensary, not visible to the public, and be sold only by a pharmacist or pharmacy technician. Doctors may also prescribe prescription drugs for off-label use – purposes which the drugs were not originally approved for by the regulatory agency. The Classification of Pharmaco-Therapeutic Referrals helps guide the referral process between pharmacists and doctors.

The International Narcotics Control Board of the United Nations imposes a world law of prohibition 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. Many countries, such as the United Kingdom have a third category of "pharmacy medicines", which can be sold only in registered pharmacies by or under the supervision of a pharmacist.

Medical errors include over-prescription and polypharmacy, mis-prescription, contraindication and lack of detail in dosage and administration instructions. In 2000 the definition of a prescription error was studied using a Delphi method conference; the conference was motivated by ambiguity in what a prescription error is and a need to use a uniform definition in studies.

Drug pricing

In many jurisdictions, drug prices are regulated.

United Kingdom

In the UK, the Pharmaceutical Price Regulation Scheme is intended to ensure that the National 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, the Association of the British Pharmaceutical Industry (ABPI). For 2017 this payment percentage set by the PPRS will be 4,75%.

Canada

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" different countries that the prices are being compared to are the following: France, Germany, Italy, Sweden, Switzerland, the United Kingdom, and the United States.

India

In India, drug prices are regulated by the National Pharmaceutical Pricing Authority.

United States

In the United States, drug costs are partially unregulated, but instead are the result of negotiations between drug companies and insurance companies.

High prices have been attributed to monopolies given to manufacturers by the government. 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.

==Blockbuster drug==

A blockbuster drug is a drug that generates more than $1 billion in revenue for a pharmaceutical company in a single year. Cimetidine was the first drug ever to reach more than $1 billion a year in sales, thus making it the first blockbuster drug.