A drug is a chemical compound that is used to treat, cure, mitigate, diagnose, or prevent a disease or illness. This, however, creates the misconception that any chemical compound having therapeutic action can be used as a drug. Unfortunately, this is not the case, as a therapeutic active chemical compound with specified standard of quality and purity (specifications are available in pharmacopoeia or standard reference) and with a administrable form (formulation) is used. The Formulated drug is customarily know as medicine.
This is explained as follows:
Aspirin: an example of therapeutic active chemical compound
Aspirin IP (standard of purity): an example of drug
Aspirin IP Tablet: an example of medicine
Legal definition: According to Drugs and Cosmetics Act 1940 “Drug” includes (a) all medicines and all substances intended to be used for or in the diagnosis, treatment, mitigation or prevention of any disease or disorder; (b) substances intended to affect the structure or any function of the human body; (c) substances intended for use as components of a drug; and (d) devices intended for use in the diagnosis, treatment, mitigation or prevention of disease or disorder.
New drug development: It is undeniable fact that therapy with a drug (chemotherapy) is a major factor that has contributed to the advancement of public health and quality of life. Today a person can, on an average, live twice as long as his great-grandparent, whose life expectancy was barely 40 years. People today owe medicines their good health and eventually their lives. Over the years legislations worldwide restrict the availability of only relatively safe drugs in the market (benefit to risk ratio is more for the disease).
The normal discovery and development time for a drug varies between 8 and 14 years. The rule of thumb in search for a new drug: only one out of 10000 compounds synthesized manages all obstacles of clinical trials and becomes a drug. The invention of a new drug and its development into a suitable dosage form cost as high as 800 million USD.
Drugs or medicines?
The word drug in any standard dictionary has two meanings- medicine or illegal substance. While medicine is defined in the dictionary as a substance which is drunk or swallowed as a treatment for illness or injury, on the contrary drug is defined as a chemical substance which is taken for pleasure or to improve someone’s performance of an activity. Since the word ‘drugs‘ is sometimes associated with drugs of abuse or misuse rather than therapeutic agent, increasingly the word ‘medicines‘ is being adopted worldwide to ensure that they are used to the benefit of people’s health.
Safety issues of medicine use
Modern medicines are very powerful, highly specific and have a great potential for alleviating suffering and curing diseases, but are also prone to misuse and causing dangerous adverse effects. Swiss physician and alchemist, Paracelsus, almost 600 years ago, quoted “All substances are poisons; there is none which is not poison. The right dose differentiates a poison and a remedy“. The potential of all medicines to cause harm is universal. Medicines are taken by patients with an expectation of benefit and usually with awareness that side effects might occur. The US FDA approval certifies for marketing when a Medicine’s benefits outweigh its risks. Safety means relative absence of harm or a low level of risk that can be considered acceptable. Safety is just like a moving ball – there is need to evaluate outcome, and a medicine previously considered acceptably safe may become unsafe as a result of new findings of adverse event. Continuous evaluation of safety of medicines in general and post marketing safety monitoring in particular is the only way out.
Rational use of medicines
All medicines work best in keeping a patient healthy when they are used wisely and as directed. Unfortunately, there is consistent evidence that the prescribing and use of medicines in India, like many other low-income developing countries, is sub-optimal. Well known examples are inappropriate combinations of medicines, poly pharmacy, poor patient compliance and overuse of antibiotics or injections. There are many reasons for this dismal situation.
Prescription and Over the counter (OTC) medicines
Schedule H to the Drug and Cosmetics Rules,1945 mentions a list of medicines that should be sold by retail on the prescription of a physician. Schedule X specifies a list of habit forming medicines/drugs requiring prescription in duplicate. In India, these two lists of medicines are defined as prescription medicines and legally should be sold only on prescription. The main criteria for determining whether a medicine is to be restricted to prescription-only distribution is direct or indirect danger to health if used without medical supervision.
OTC is an acronym that stands for Over-the-Counter medicines. This pertains to medicines which are legally allowed to be sold over the counter without the prescription. They are, therefore, also called non-prescription medicines. OTC medicines are safe and are sold to treat minor, common, self-limiting illnesses and conditions.The most important distinction between prescription and OTC medicine is based on the availability of adequate directions for use under which a layman can use the medicine safely and for the purposes for which it is intended.