A drug is, in the broadest of terms, a chemical substance that has known biological effects on humans or other animals. Foods are generally excluded from this definition, in spite of their physiological effects on animal species.
In pharmacology, a drug is "a chemical substance used in the treatment, cure, prevention, or diagnosis of disease or used to otherwise enhance physical or mental well-being."
Psychoactive drugs are chemical substances that affect the function of the nervous system, altering perception, mood or consciousness. Alcohol, nicotine, and caffeine are the most widely consumed psychoactive drugs worldwide.
Recreational drugs are drugs that are not used for medicinal purposes, but are instead used for pleasure. Common recreational drugs include alcohol, nicotine and caffeine, as well as other substances such as opiates and amphetamines.
Some drugs can cause addiction and habituation and all drugs can cause side effects. Many drugs are illegal for recreational purposes and international treaties such as the Single Convention on Narcotic Drugs exist for the purpose of legally prohibiting certain substances.
Etymology
In English, the noun "drug" is thought to originate from Old French "drogue", possibly deriving later into "droge-vate" from Middle Dutch meaning "dry barrels", referring to medicinal plants preserved in them. The transitive verb "to drug" arose later and invokes the psychoactive rather than medicinal properties of a substance.
Medication
A medication or medicine is a drug taken to cure and/or ameliorate any symptoms of an illness or medical condition, or may be used as preventive medicine that has future benefits but does not treat any existing or pre-existing diseases or symptoms.
Dispensing of medication is often regulated by governments into three categories—over-the-counter medications, which are available in pharmacies and supermarkets without special restrictions, behind-the-counter, which are dispensed by a pharmacist without needing a doctor's prescription, and prescription only medicines, which must be prescribed by a licensed medical professional, usually a physician.
In the United Kingdom, BTC medicines are called pharmacy medicines which can only be sold in registered pharmacies, by or under the supervision of a pharmacist. These medications are designated by the letter P on the label. The range of medicines available without a prescription varies from country to country.
Medications are typically produced by pharmaceutical companies and are often patented to give the developer exclusive rights to produce them. Those that are not patented are called generic drugs since they can be produced by other companies without restrictions or licenses from the patent holder.
Spiritual and religious use
The spiritual and religious use of drugs has been occurring since the dawn of our species. Drugs that are considered to have spiritual or religious use are called entheogens. Some religions are based completely on the use of certain drugs. Entheogens are mostly hallucinogens, being either psychedelics or deliriants, but some are also stimulants and sedatives.
Self-improvement
Nootropics, also commonly referred to as "smart drugs", are drugs that are claimed to improve human cognitive abilities. Nootropics are used to improve memory, concentration, thought, mood, learning, and many other things. Some nootropics are now beginning to be used to treat certain diseases such as attention-deficit hyperactivity disorder, Parkinson's disease, and Alzheimer's disease. They are also commonly used to regain brain function lost during aging. Similarly, drugs such as steroids improve human physical capabilities and are sometimes used for this purpose, often by professional athletes.
Recreational drug use
Recreational drugs use is the use is the use of a drug with the primary intention of altering the state of consciousness in order to create positive emotions and feelings.
Some national laws prohibit the use of many different recreational drugs and medicinal drugs that have the potential for recreational use are heavily regulated. Many other recreational drugs on the other hand are legal in many jurisdictions and widely culturally accepted. These may nevertheless have an age restriction on using and/or purchasing them. These include alcohol, tobacco, betel nut, and caffeine products in the west, and in other localised areas of the world drugs such as Khat are common. Because of the legal status of many drugs, illegal recreational drug use is controversial, with many governments not recognising spiritual or other perceived uses for drugs.
Administering drugs
Drugs, both medicinal and recreational, can be administered in a number of ways, or routes. Many drugs can be administered via more than one route.
Bolus is the administration of a medication, drug or other compound that is given to raise its concentration in blood to an effective level. The administration can be given intravenously, by intramuscular, intrathecal or subcutaneous injection.
Inhaled,, as an aerosol or dry powder.
Injected as a solution, suspension or emulsion either: intramuscular, intravenous, intraperitoneal, intraosseous.
Insufflation, or snorted into the nose.
Orally, as a liquid or solid, that is absorbed through the intestines.
Rectally as a suppository, that is absorbed by the rectum or colon.
Sublingually, diffusing into the blood through tissues under the tongue.
Topically, usually as a cream or ointment. A drug administered in this manner may be given to act locally or systemically.
Vaginally as a suppository, primarily to treat vaginal infections.
See also
Drug development
Drug injection
Inverse benefit law
Lifestyle drug
List of drugs
List of pharmaceutical companies
List of psychedelic plants
Placebo
Prodrug
United Nations Office on Drugs and Crime
References
Further reading
Richard J. Miller: Drugged: The Science and Culture Behind Psychotropic Drugs. Oxford University Press, 2014. ISBN 978-0-19-995797-2
External links
, a database of 4800 drugs and 2500 protein drug targets