Definition of Drugs: Terminology, Types, Classification, Presentations and Expiration

Also known as medicine or drug, it can be loosely defined as any chemical substance intended for use in medical diagnosis.

Also for the cure, treatment or prevention of diseases.

The drugs are classified in several ways. One of the key divisions is by level of control, which distinguishes prescription drugs (those dispensed by a pharmacist only by order of a physician, physician assistant or qualified nurse) from over-the-counter medications (those that consumers can order for themselves). themselves).

Medication (also called medicine or medication) is the use of legal drugs to treat or cure a disease. Some drugs are sold freely. They are called over-the-counter (OTC) medications.

Other drugs are so powerful or dangerous that a doctor must give permission to use the drug. The doctor’s note is called a “prescription.” These medications are called prescription drugs or prescription drugs.

Another key distinction is between traditional small molecule drugs, generally derived from chemical synthesis, and biopharmaceutical products, which include recombinant proteins, vaccines, therapeutically used blood products, gene therapy, monoclonal antibodies and cell therapy (for example, stem cell therapies) .

Other ways to classify drugs are by mode of action, route of administration, affected biological system or therapeutic effects.

An elaborated and widely used classification system is the Anatomical Therapeutic Chemical Classification System (ATC system). The World Health Organization maintains a list of essential medicines.

Drug discovery and drug development are complex and expensive tasks carried out by pharmaceutical companies, academic scientists and governments.

As a result of this complex path from discovery to commercialization, the association has become a standard practice for advancing drug candidates through development channels.

Governments usually regulate which drugs can be marketed, how medicines are marketed, and, in some jurisdictions, the prices of medicines. Controversies have arisen over the prices of medicines and the elimination of used drugs.

There are many different words to describe important things about medications.

Dosage of medications

The dose is the amount of medication that must be taken for the medicine to do what it is supposed to do.

Dosing is very important because all medications can be toxic if taken in large quantities. If a person takes too much of a medication, they can get sick or even die.

This is called an overdose. For example, if a person takes too much acetaminophen (also called paracetamol, Tylenol or Panadol), it can severely damage their liver.

Some doses are based on age. For example, children often need fewer medications than adults. Others are based on body weight. Sometimes, normal doses should be changed if a person has certain medical problems, such as kidney failure .


The action is what the medicine is supposed to do, the useful effects the medicine is supposed to have on the body.

Many drugs have more than one action. For example, paracetamol is an analgesic (eliminates pain) and an antipyretic (makes fevers disappear).

Indication of medications

An indication is a reason why a medication is given.

Many drugs have more than one indication. For example, indications for paracetamol include pain and fever.


A contraindication is a reason why a medication should not be administered.

Almost all medicines, including over-the-counter medicines, have some contraindications. For example, acetaminophen should not be given to people who are allergic to acetaminophen.

For these people, paracetamol is “contraindicated”, and another medication should be used instead. Acetaminophen is also contraindicated in people who have liver disease.

Side effects and adverse effects of medications

A person takes a medication because he wants it to do certain things. When the medication also does other things that the person did not want, these are called side effects. For example, paracetamol can cause nausea. This is a side effect of paracetamol.

Adverse effects are side effects that are dangerous or harm the body. For example, in some people, paracetamol can damage the liver. This is an adverse effect of paracetamol.

Most medications have many possible side effects. This does not mean that anyone who takes the medication will have those side effects. For example, not all people taking acetaminophen have nausea.

A side effect is just a possible effect that a medication can have on the body.

Name (s

All medications have some different names.

Chemical name of the medicines:

When a drug is discovered for the first time, it is assigned a chemical name. This name describes the atoms or molecules in the medicine. In general, only scientists use this name.

For example, the chemical names for paracetamol are N-acetyl-para-aminophenol and para-acetyl-amino-phenol.

Generic name of the medicines:

Each country has a generic (official) name for each drug.

In the United States, a drug receives an official generic name after the Food and Drug Administration (FDA) says it is safe to sell it. For example, acetaminophen is the official generic name used in the United States.

Sometimes generic names come from the chemical name of a medicine. For example, paracetamol is called N-acetyl-para-amino-phenol, and paracetamol is called para-acetyl-amino-phenol.

Brand name:

Each company that produces a drug gives it a brand name. No other company can use this name.

For example, in the United States, the most common brand name for acetaminophen is Tylenol. One of the companies that makes acetaminophen ( Johnson & Johnson ) chose the name “Tylenol” for its acetaminophen.

Another company that makes acetaminophen ( GlaxoSmithKline ) chose “Panadol” as its brand name. As with most medications, there are many other brands of paracetamol.


Some medications have unofficial abbreviations. For example, paracetamol is sometimes abbreviated APAP. This comes from the chemical name of the drug: N-Acetyl-Para-Amino-Phenol.

The same medicine:

No matter which of these names is used, they all describe the same medication. For example, there is no difference between N-acetyl-para-aminophenol, acetaminophen, paracetamol, Tylenol, Panadol and APAP.

Administration of medicines

There are many ways in which medications can be administered. These are called “administration routes”.

For most medications to work, they need to enter the bloodstream. The blood carries the medication throughout the body and takes it to where it is needed. The way a medication is administered affects:

  • The path that medicine takes to enter the bloodstream and how long this takes.
  • How much of the medicine enters the bloodstream.
  • How much medicine reaches the tissue where it is needed?
  • How long will the effects of the medication last?

Medications for oral administration:

The most common way to administer medications is by mouth. The medicine comes in a pill or liquid that a person swallows.

When taken orally, medication enters the bloodstream through the digestive system. The medication takes a while, usually 15 to 20 minutes, to pass through parts of the digestive system and be absorbed into the bloodstream.

In addition, a very small amount of the medication enters the bloodstream. This is because the acid in the stomach kills most of the medication before it can be absorbed into the bloodstream.

Oral medications often last longer than medications taken by other routes of administration.

Not all medications can be administered orally. With some medications, such as insulin, the acid in the stomach will change the medication or break it down so much that it will not work.

Intravenous administration medications:

Some medications can be given through a needle placed in a vein. This form of medication is called intravenous (IV).

This is one of the fastest ways to introduce medications into the bloodstream. The veins carry blood, so when a drug is given intravenously, it goes directly into the bloodstream immediately.

It takes less than a minute for blood to flow throughout the body. This means that when administered intravenously, a medication will reach the brain in a minute or less. All medicine (100%) enters the bloodstream.

However, intravenous medications will not last as long as medications given orally.

This is because the body begins to metabolize drugs (breaking them down so that the body can get rid of them) as soon as the medicine enters the bloodstream. Not all medications can be given intravenously.

Medications for muscle administration:

Some medications can be given through a needle placed in a large muscle, such as the muscles of the upper arm, thigh, or buttocks. This form of medication is called intramuscular (IM).

When a drug is given intramuscularly, the medicine enters the bloodstream through smaller blood vessels in the muscles.

This takes more time than an intravenous injection because the medication is not injected directly into a blood vessel. However, the medication still reaches the bloodstream faster than medications given orally.

In addition, not all medication enters the bloodstream because part of it is trapped in the soft tissue of the muscle and never reaches the blood vessels.

Inhaled medications:

You can breathe some special medications. This form of medication is called inhalation (sometimes abbreviated INH).

This can be especially useful for lung problems such as asthma . Since the medication is breathed directly into the lungs, you can start working on the lungs immediately.

Administration of medicines by other routes:

There are many other administration routes. For example:

In the bone (intraosseous (IO)): A needle is placed in a large bone, such as the femur (thigh bone), and medications are given in the bone marrow. Any medication that can be administered in a vein can also be administered in a bone.

As with intravenous medications, all medications enter the bloodstream immediately. Intraosseous drugs can only be administered by certain medical professionals, such as doctors and paramedics.

In the rectum (for rectum (PR)): Some medications can be given in the rectum. The medication does not enter the bloodstream very quickly. This route is used primarily with people who can not swallow medications, such as very young children or people who are vomiting.

Under the skin (subcutaneous (sub-q)): Some special medications can be given through a needle placed under the skin. For example, insulin is often administered in this way.

On the nose (intranasal): Some special medications can be sprayed on the nose. When a medicine is given intranasally, all the medicine goes to the brain, immediately.

For example, naloxone (used to treat opioid overdoses) can be administered intranasally. There are many other administration routes.

Many medications can be administered in more than one way. For example, paracetamol can be administered orally, in the rectum or in a vein.

Expiry dates

The expiration date, required in several countries, specifies the date until which the manufacturer guarantees the full potency and safety of a medicine.

In the United States, expiration dates are determined by the rules established by the food and medication administration.

The Food and Drug Administration advises consumers not to use products after their expiration dates.

A study conducted by the US Food and Drug Administration. UU, covered more than 100 medications, prescribed and without a prescription. The results showed that around 85% of them were safe and effective up to 15 years after their due date.

Joel Davis, former chief compliance officer for the expiration date of the food and drug administration, said that with a handful of exceptions, especially nitroglycerin, insulin, some liquid antibiotics; obsolete tetracyclines can cause Fanconi syndrome; Most expired drugs are probably effective.

The American Medical Association (AMA) issued a report and a statement on pharmaceutical expiration dates.

The Harvard Medical School Family Health Guide notes that, with rare exceptions, “it is true that the effectiveness of a drug may decrease over time , but much of the original potency still remains a decade after the expiration date” .

The expiration date is the last day on which the manufacturer guarantees the full potency and safety of a medicine.

Drug expiration dates exist on most drug labels, including prescription drugs, over-the-counter (OTC) medications, and dietary (herbal) supplements.

The law requires manufacturers of US pharmaceuticals. UU That they put expiration dates on the prescription products before they are commercialized.

For legal and liability reasons, manufacturers will not make recommendations about the stability of the drugs after the original expiration date.

Cost of medicines

The prices of prescription drugs vary widely throughout the world. Prescription costs of biosimilar and generic drugs are usually lower than those of brands, but the cost is different from one pharmacy to another.

The prices of prescription drugs, including the prices of generic drugs, are rising faster than the average rate of inflation. To subsidize the costs of prescription drugs, some patients have decided to buy drugs online.

Generics undergo strict scrutiny to meet the same efficacy, safety, dosage, strength, stability and quality of brand name drugs.

Generics develop after the brand has been established, so generic drug approval in many ways has a shorter approval process because it replicates the brand name drug.

Brand-name drugs cost more because of the time, money and resources that pharmaceutical companies invest to repeat the clinical research trials that the administration of food and medicine requires in order for the drug to remain on the market.

Because pharmaceutical companies have to invest more in research costs to do this, the prices of brand-name drugs are much higher when they are sold to consumers.

When the patent expires for a brand-name drug, the generic versions of that drug are produced by other companies and sold at a lower price.

By switching to generic prescription drugs, patients can save significant amounts of money: a study conducted by the food and drug administration showed an example with more than 50% savings in a patient’s total costs of their prescription drugs.

Pharmaceutical packaging

Pharmaceutical containers (or medicine containers) are packaging packages and processes for pharmaceutical preparations. It involves all operations from production to the distribution channels and the final consumer.

Pharmaceutical packaging is highly regulated but with some variations in the details, depending on the country of origin or the region.

Several common factors may include ensuring the safety of the patient, ensuring the efficacy of the drug through the expected lifespan, uniformity of the drug through different batches of production, comprehensive documentation of all materials and processes.

Also control of the possible migration of components of the container, control of the degradation of the drug by oxygen, humidity, heat, etc., prevention of microbial contamination, sterility, etc.

Packaging is often involved in the dispensing, dosing and use of the pharmaceutical product.

The communication of proper use and caution labels are also regulated. Packaging is an integral part of the pharmaceutical product.

Medicine package forms:

The wide variety of pharmaceutical solids, liquids and gases is packaged in a wide variety of packages. Some of the common main packages are:


The solid unit doses formed of pharmaceutical products (capsules, suppositories, tablets, etc.) are commonly packaged in blister packs.

Blisters are preformed plastic / paper / aluminum containers used for solid medications formed. The main component of a blister is a cavity or pocket made of a thermoformed plastic.

This usually has a cardboard backing or a lid seal made of foil or plastic film. Blister packs are useful to protect medications against external factors, such as humidity and contamination for long periods.


Bottles are commonly used for liquid pharmaceuticals, as well as for tablets and capsules formed. Glass is more common for liquids because it is inert and has excellent barrier properties.

Several types of plastic bottles are used by both drug producers and pharmacists in a pharmacy.

Prescription bottles have existed since the 19th century. During the nineteenth and twentieth centuries, bottles of prescription drugs were called medicinal bottles. There are many styles and forms of prescription bottles.

Prescription bottles come in various colors, the most common being orange or light brown due to its ability to prevent ultraviolet light from degrading potentially photosensitive contents through photochemical reactions, while leaving enough visible light for the contents to be easily visible .

Other common colors include: Clear (for compounds that do not degrade in light), blue, dark brown, green and various opaque shades.

Scheduled dosage:

Some mail-order pharmacies now offer scheduled dosage packages for medications.

They place a certain number of pills, as indicated by the doctor in a plastic package and print the date and time that the medications should be taken.

It is used for people with multiple medications that are taken at different times of the day.