A medication is a licensed drug taken to cure or reduce symptoms of an illness or medical condition. Medications are typically produced by pharmaceutical companies and are often patented to protect their exclusive rights to produce them, but they can also be derived from naturally occurring substances in plants called herbal medicine. Those that are not patented (or with expired patents) are called generic drugs since they can be produced by other companies without restrictions or licenses from the patent holder. Referring to medications by their generic name rather than their brand name is important.[1][2]
Zoopharmacognosy is animal usage of drugs and non-foods.
Medication can be usually classified in various ways, e.g. by its chemical properties, mode of administration, or biological system affected. An elaborate and widely used classification system is the Anatomical Therapeutic Chemical Classification System.
Medications are generally divided into groups by the United States and similar laws.
Over-the-counter drug (OTC) medications, which are available in pharmacies and supermarkets without special restrictions
Behind the counter (BTC) are dispensed by a pharmacist without needing a doctor's prescription,
Prescription only medicines (POM), which must be prescribed by a physician, physician assistant, nurse practitioner, or dentist. These medications are approved by national entities such as the Food and Drug Administration in the United States or by international entities such as the European Medicines Agency (EMEA) of the European Union and United Kingdom’s Medicines and Healthcare Products Regulatory Agency.
The approval process may not study adequate number of patients for sufficient period of time.[3]
The International Narcotics Control Board of the United Nations imposes a world law of prohibition or censorship of certain medications. They publish a lengthy list of chemicals and plants whose trade and consumption (where applicable) is forbidden. Most OTC medication is generally considered to be safe enough that most persons will not hurt themselves accidentally by taking it as instructed. Many countries, such as the UK have a third category of pharmacy medicines which can only be sold in registered pharmacies, by or under the supervision of a pharmacist. However, the precise distinction between OTC and prescription depends on the legal jurisdiction.
Medication guides, or labels are given by the pharmacist with every prescription. It generally includes description, clinical pharmacology (pharmacokinetics, pharmacodynamics), clinical trials, indications and usage, contraindications, warnings, precautions, adverse reactions, dosage and administration, overdosage, how supplied, storage, revision date and manufacturer and distributor.
United States Food and Drug Administration approved labels
European Union
United Kingdom
Polypharmacy: suggests that multiple use of prescribed and non-prescribed medications, (use of 5 or more), can have adverse effects on the recipient.
Unfortunately, drugs may also cause drug toxicity (also called drug-related side effects and adverse reactions or adverse drug event).
Many drugs, but not epinephrine in EpiPen, may be effective after their expiration date.[4]
Off label promotion of medications is problematic.[5]
Free samples of medications provided to the offices of health care providers may be problematic.[6] The provision of free samples by doctors is decreasing but is more common in regions of high Medicare expenditures.[7]