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."Directive 2004/27/EC of the European Parliament and of the Council of 31 March 2004 amending Directive 2001/83/EC on the Community code relating to medicinal products for human use – Article 1". Published 31 March 2004. Accessed 17 August 2008. . 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).FDA, "Drugs@FDA Glossary of Terms". .
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,https://www.medthority.com database of prescription pharmaceutical products including drug classifications https://www.medthority.com/drugs/ 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: +TypeDefinitionExamplesAnalgesicsUsed to relieve painAcetylsalicylic acid (ASA), acetaminophen (paracetamol), ibuprofenAntibioticsUsed to kill or inhibit the growth of bacteriaPenicillin, amoxicillin, ciprofloxacinAntifungalsUsed to kill or inhibit the growth of fungal pathogensClotrimazole, fluconazole, metronidazoleAntihistaminesUsed to reduce allergy symptomsDiphenhydramine, cetirizine, loratadineAntipyreticsUsed to reduce feverAcetylsalicylic acid (ASA), acetaminophen (paracetamol)AntiviralsUsed to kill or inhibit the growth of viral pathogensAcyclovir, ganciclovir, oseltamivirAnticoagulantsUsed to prevent blood clot formationApixaban, heparin, enoxaparinAntidepressantsUsed to manage depression and related mental health conditionsSertraline, fluoxetine, bupropionAntineoplasticsUsed in the treatment of cancerCyclophosphamide, etoposideAntipsychotics Used to manage severe mental health conditions (such as schizophrenia, treatment-resistant depression)Haloperidol, clozapine, aripiprazoleBronchodilatorsUsed to open the airways in the lungsAlbuterol, formoterol, tiotropiumCorticosteroidsUsed to reduce inflammation throughout the bodyDexamethasone, prednisone, triamcinoloneMood StabilizersUsed to treat bipolar disorder and other mood-related conditionsLithium, lamotrigineStatinsUsed to lower blood cholesterol levelsAtorvastatin, rosuvastatin, pravastatinAntacidsNeutralize stomach acid to relieve heartburn and indigestionCalcium carbonate, magnesium hydroxideProton pump inhibitors (PPIs)Reduce stomach acid production by blocking proton pumpsOmeprazole, pantoprazole, lansoprazoleH2 receptor antagonistsReduce stomach acid by blocking histamine H2 receptorsFamotidine, ranitidine (withdrawn in many countries)AntiemeticsUsed to prevent or treat nausea and vomitingOndansetron, metoclopramide, promethazineAnticonvulsantsUsed to manage or prevent seizuresValproic acid, carbamazepine, oxcarbazepineDiureticsPromote urine production to reduce fluid overload and lower blood pressureFurosemide, hydrochlorothiazide, bumetanideBeta blockersLower heart rate and blood pressure by blocking beta-adrenergic receptorsMetoprolol, propranolol, atenololCalcium channel blockersRelax blood vessels and reduce blood pressureAmlodipine, diltiazem, nicardipine, clevidipineACE InhibitorsLower blood pressure by inhibiting angiotensin-converting enzymeEnalapril, ramipril, lisinoprilAntidiabeticsUsed to manage blood glucose levels in diabetesMetformin, insulin, gliclazideThyroid hormonesReplace or supplement thyroid hormone levelsLevothyroxine, liothyronine, Hormonal contraceptivesPrevent pregnancy by altering hormonal regulationethinyl estradiol/norgestimate, levonorgestrelSedatives / HypnoticsInduce or maintain sleep, reduce anxietyZopiclone, alprazolam, zolpidemStimulantsEnhance alertness, attention, and energyMethylphenidate, amphetamine, caffeineImmunosuppressantsSuppress immune response to prevent organ rejection or treat autoimmune diseaseCyclosporine, tacrolimus, adalimumabVaccinesStimulate the immune system to prevent infectious diseaseInfluenza 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: TypeDefinitionExamplesOral and MucosalOralTaken by mouth; the most common route of administrationTablets, capsules, syrupsSublingual Placed under the tongue for rapid absorption into the bloodstreamNitroglycerin, buprenorphineBuccalPlaced between the gum and cheek; absorbed through oral mucosaFentanyl, misoprostolLocal ApplicationTopicalApplied directly to the skin or mucous membranes to treat localized conditionsNeosporin, mometasone ointment, clobetasol lotionOphthalmicApplied to the eyes for local treatmentArtificial tears, timolol eye dropsOticApplied into the ear canal for local treatmentAntibiotic ear drops (combo ciprofloxacin with dexamethasone)NasalSprayed or instilled into the nose for local or systemic absorptionFluticasone nasal spray, naloxone nasal spraySuppositoriesDelivers medication via the rectum, vagina, or urethra, depending on formulationRectal suppositories, vaginal pessariesTransdermalDelivers medication through the skin for systemic absorption, bypassing the digestive systemTransdermal patches (e.g., fentanyl, nicotine), transdermal gels (e.g. estradiol, diclofenac)InhalationInhalersDelivers medication directly to the lungs, most often used for respiratory conditionsSalbutamol metered-dose inhalers (MDIs), Mometasone furoate dry powder Inhalers (DPIs)NebulizedDelivered as fine mist via nebuilizer especially for children or severe respiratory casesHypertonic saline, ipratropiumParenteral (injectable)IntramuscularInjected into a muscle, typically the deltoid or gluteus. Commonly used for vaccines and fast-acting medicationsInfluenza vaccine, epinepherineSubcutaneousInjected into the fatty tissue beneath the skin. Commonly used for biologics, hormones, and insulin.Insulin, low-molecular-weight heparinIntravenousInjected directly into a vein for immediate systemic effect. Commonly used for emergency medications, fluids and chemotherapyMorphine, vancomycin, chemotherapy drugsIntradermalInjected into the dermis (just under the skin surface). Commonly used for allergy tests, tuberculosis screeningTuberculin (Mantoux test)IntrathecalInjected into the cerebrospinal fluid within the spinal canal. Commonly used for chemotherapy and spinal anesthesia.Methotrexate (for CNS cancers), bupivacaineEpiduralInjected into the epidural space around the spinal cord. Commonly used for pain management, anesthesia during childbirthFentanyl, bupivacaineIntraarticularInjected into a joint space. Commonly used for joint inflammation (e.g. arthritis)Triamcinolone, ketorolac, ropivacaineIntraosseousInjected directly into the bone marrow (emergency access when IV not possible). For emergency medicine in paediatrics and traumaFluids, epinephrine via IO deviceOtherImplantSurgically placed or subdermal device that releases medication over timeContraceptive 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.