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Common medicine related for the general folk!

· 9 min read
Hirusha Adikari
Hirusha Adikari
I do stuff sometimes...

Well, first of all, I am the general folk and this is from some research I did in my free time. Everytime time I google a drug, I get bombarded with these weird abbreviations and terms. I'm writing this to both remember stuff more and improve my understanding further. This post is more of an index for my future self incase I forget something (which I definitely will!).

Note that in this post, whenever I use the term "drug", I refer to medicine / medicinal drugs.

NOTE

This is still incomplete!

Drug Names​

You can refer to medicine by using three different names. Two of these three names are the most commly used. The chemical name is not commonly seen, not even in the health sector.

To keep things easy, we will be sticking with a drug commonly referred to as Tylenol or Paracetamol.

Chemical Name​

Tylenol's chemical name is "N-acetyl-para-aminophenol".

This is how you read the chemical formula. This is the scientific name of the actual molecule / compound and its written following the rules from IUPAC (International Union of Pure and Applied Chemistry).

This is probably used by chemists and drug researchers. This is not commonly used by doctors or other healthcare workers on a daily basis.

Generic Name​

This is what's being used by healthcare workers on a daily basis.

Using the generic name instead of the brand name will avoid confusion and makes communication easier, specially if you are travelling. Doctors, pharmacists, and researchers use generic names because they describe the same active ingredient, no matter what brand or country.

Types​

Generic names are meant to be "generic" but as always, there are three popular standards.

1. INN (International Nonproprietary Name)​

The generic name of Tylenol is Paracetamol, following the INN standard.

This is the global standard maintained by the WHO (World Health Organization). The goal here is to make sure that every drug has one unique name that is used internationally.

Most European countries, Australia, Sri Lanka, India and many others follow this standard.

2. USAN (United States Adopted Name)​

The generic name of Tylenol is Acetaminophen, following the USAN standard.

As usual, the US has it's own naming system. This is managed by the American Medical Association and the U.S. Adopted Names Council. Sometimes the USAN name of a drug is the same and the INN name, and sometimes it's not.

This standard is what I like to use as most of the modern research and online articles are from US based writers and researchers.

3. BAN (British Approved Name)​

The UK stopped using the INN standard and swicthed to their own. In most cases, this is exactly the same as INN.

Just dont use this. Use either INN or USAN.

Trade Name​

Some trade names of Acetaminophen are:

  • Tylenol manufactured by Kenvue / Johnson & Johnson.
  • Panadol manufactured by Haleon / GSK.
  • Click here to open a massive list.

The big pharmaceutical companies manufacture their drugs and they use a catchy name for marketing. This is called the trade name. This is done to make their drug stand out from the same drug manufactured by other manufacturers.

Let's look at some other drugs.

INNUSANTrade Name
ParacetamolAcetaminophenTylenol
AdrenalineEpinephrineEpiPen
SalbutamolAlbuterolVentolin

Now that the naming of drugs has been discussed, I will only use USAN generic name from here onwards.

Sometimes, multiple active ingredients are combined together. Let's look at some examples.

  • Panadeine = Acetaminophen/Paracetamol + Codeine phosphate
    • Acetaminophen: An NSAID used an a mild analgesic and antipyretic.
    • Codeine phosphate: A weak opioid-based painkiller
  • Augmentin = Amoxicillin + Clavulanate potassium acid
    • Amoxicillin: a β-lactam antibiotic that kills bacteria by interfering with cell-wall synthesis.
    • Clavulanate potassium: a β-lactamase inhibitor that prevents bacteria from destroying amoxicillin, making it more affective.
  • Co-trimoxazole = Sulfamethoxazole + Trimethoprim
    • Sulfamethoxazole: a sulfonamide antibiotic that blocks one step in bacterial folic acid synthesis.
    • Trimethoprim: blocks a different step in the same pathway.
    • Both of them combined together gives a "one plus one equals more than two" action. This is called the "synergistic effect".
  • Co-careldopa: = Carbidopa + Levodopa
    • Levodopa: A dopamine precursor used to treat Parkinson’s disease; it increases dopamine levels in the brain to improve movement
    • Carbidopa: Prevents the premature breakdown of levodopa before it reaches the brain, reducing side effects such as nausea and allowing even a smaller dose of levodopa to be effective.

Drug Class​

Ok, so... this is something that never ends and there are probably thousands of things to list here.

Drugs can be categorized by their

  • Chemical classes
  • Mechanism of action
  • Mode of alternative
  • Therapautic class
  • Amalgamated class
  • and one of the many other classification systems

Listing out everything and explaining them in detail goes both beyond the scope of this post as well as my intellect.

Just look things up as you meet them. Google and MDWiki are your friends. If you are already familiar with some basic terminology, some drug class names should make sense. However, I would always suggest you to read more into it just to confirm. An inaccurate assumption is worse than not assuming anything at all.

Pregnancy Risk Categories​

Every drug has a side effects and is at least slightly toxic! Yes! Even Acetaminophen. That’s why it’s important to know how medications are classified when it comes to pregnancy. Pregnancy risk categories are a way of describing how safe or risky a medication is to use during pregnancy, based on the available scientific evidence of potential harm to the fetus.

These categories help doctors, pharmacists, and even patients quickly understand whether a medication is considered safe, risky, or somewhere in between. The idea is to balance the potential benefits of treating the mother against any possible risks to the fetus. Just like the drug names, there are multiple standards for this as well. We will focus on the main three.

Apart from pregnancy, drugs are also assessed for how they might affect labor and delivery ("Labor and Delivery") or whether they are safe during breastfeeding ("Lactation"). However, the pregnancy classification is the one you’ll see most often.

Keep in mind that "safe" might not always mean it's completely harmless as they are classified only from what we know.

FDA System (Old)​

This was the classic classification approach used until 2015. Eventhough this has been deprecated, this can still be seen almost everywhere. Each risk catgeory is given a letter from "A, B, C, D, X" and N with A being the safest and X being the most harmful. Let's break this down.

Catgeory A​

TLDR: Safe to use

Adequate and well-controlled studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters). Some examples includes Levothyroxine, Acetaminophen and many more...

Catgeory B​

TLDR: Probably safe

Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women. Some examples includes Metformin, Amoxicillin, Cyclobenzaprine and many more...

Catgeory C​

TLDR: Use only if necessary

Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks. Some examples includes Gabapentin, Amlodipine, Trazodone and many more...

Catgeory D​

TLDR: Usually avoid, unless life threatening situation to the mother.

There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks. Some examples include Losartan Potassium and many more...

Catgeory X​

TLDR: Contraindicated in pregnancy. Just dont!

Studies in animals or humans have demonstrated fetal abnormalities and/or there is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience, and the risks involved in use of the drug in pregnant women clearly outweigh potential benefits. Some examples include Losartan Potassium and many more... Some examples include Finasteride, Methotrexate and many more...

Catgeory N​

TLDR: Unclassified

This means that the FDA has not assigned one of the standard letters yet, as the drug is still under research or due to the lack of insufficient data to classify it as safe or bad. Unclassified doesn't mean the drug is safe.

FDA System (New, PLLR)​

After the June 30th of 2015, all prescription drugs and biologic products submitted uses the new format. The already labelled and approved prescription drugs are also being converted to the new format gradually.

Apart from that, the catgeories has slightly changed and a new catgeory related to fertility has been introduced.

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Now, instead of using simple labels, each drug should include detailed narrative summaries for all of the three categories mentioned above - Pregnancy, Lactation and Females and Males Reproductive Potential.

This information can be found in NIH's DailyMed website. For example, click here to open information about Methotrexate.

TODO: Not sure whether this is the best site ^^^

TGA System​

Route of Administration​

Pharmocokinetic Data​

Bioavailability​

Potein Binding​

Metabolism​

Elimination half-life​

Excretion​

Chemical Data​

Formula​

Molar Mass​

3D Models from JSmol​

Smiles​

References:​

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