What can you learn from the parts of the name of a drug?

Question

I've noticed that many drugs have names that end in the same syllables:

• umab
• fenib
• tinib

For example, Wikipedia on Dabrafenib lists a number of similar drugs at the bottom of the page that end with syllables like these.

What do they signify?

Answer 1

Stems and affixes tell you the class of drug (and sometimes other properties). Drugs in the same class work in a very similar way, so therefore you can tell what other drugs it's related to.

This is a massive list: https://druginfo.nlm.nih.gov/drugportal/jsp/drugportal/DrugNameGenericStems.jsp

Usually it's the suffix that tells you the most. For example:

• lisinopril, benazepril, enalapril, ramipril are ACE-Inhibitors (commonly used for blood pressure)
• penicillin, methicillin, amoxicillin, ticarcillin are beta-lactam antibiotics.
• fluoxetine, paroxetine, duloxetine, venlafaxine, sertraline are SSRI antidepressants (selective serotonin uptake inhibitors).

In fact, sometimes we refer to classes by their stem.

• Her LDL cholesterol is high, she should be on a "statin." (Class of HMG Co-A Reductase Inhibitors like simvastatin, atorvastatin)

From your list:

• -tinib = Tyrosine kinase inhibitors
• -fenib = B-Raf enzyme inhibitors
• -mab = monoclonal antibody
  • "-ZUmab" means humanized, and "-XImab" means chimeric

These and related drugs are in the realm of chemotherapy and anti-inflammatory medications.

Also, -mabs are really neat. They are antibodies (just like your body makes to recognize infections and start an immune attack), which are designed to lock onto one extremely specific thing, then cause an effect right at that spot. For example, it's been the frontier in cancer chemotherapy, as you can sometimes target to kill just the bad cells in certain cancers. Also in autoimmune diseases, they are used instead of steroids that cause effects all over the body. They're hard to produce and expensive, and not without side effects, but have lots of potential!