top of page

CNS TEST PREP: DRUG CLASSIFICATION HACK WITH CAITLIN SELF

Updated: Oct 6, 2023




Studying for the CNS exam is a long process, and we’re here to help!


Whenever possible, we want to encourage you to study smarter, not harder, and this hack for helping to learn types of pharmaceuticals has served me well over the years. This quick tip is meant to help you study for the CNS exam, but it will serve you throughout your clinical practice!


Let’s take a look at a common PPI medication called Prilosec, whose generic medication name is omeprazole.


Omeprazole, as a PPI, blocks the production of stomach acid. We have studies that have found that over time, this can cause depletions of several nutrients. We can confidently say magnesium and B12 are likely to be depleted, and calcium and iron are additional possible depletions.


Prilosec (omeprazole) Depletions:

  • High chance: magnesium, B12

  • Possible chance: calcium, iron


Rather than gathering this information for each individual medication, you can take a shortcut! Many drugs in the same category will have the same ending to their name. In the case of the PPI, the ending is “prazole.”


Say you come across a random drug you haven’t memorized - esomeprazole - now you know it is also a PPI. This means that it will most likely impact the same nutrients that are impacted by other PPIs, such as magnesium and B12.


Certainly there are some exceptions and this won’t work every single time. Thiazide diuretics, for example, go by many names. But this shortcut allows you to learn the depletions of several medications all at once! Efficiency is the name of the game when it comes to studying for the CNS exam.


Take a look at the most commonly prescribed medications and see how many in the top 50-100 can fit into the same category.


Once you’ve made categories (see examples below), you can add the common nutrient depletions. I like to use mytavin.com for this because it is a regularly updated website that links to the actual studies. There are tons of books and lists you can use as well, but most of them are frozen in time and may not have up-to-date information.


  • ACE inhibitors: (BP med) - ex: lisinopril

    • Also: benazepril, captopril, enalapril, quinapril

    • Common depletions: zinc

  • Thiazide Diuretics (BP med) - ex: hydrochlorothiazide

    • Also: chlorothiazide, hydrochlorothiazide

    • Common depletions: potassium, sodium, zinc

    • Possible depletions: magnesium, chloride, iron, folate, thiamin, vitamin C

    • Other names: chlorthalidone, indapamide, metolazone

  • Beta Blockers (BP med) - ex: atenolol

    • Also: metoprolol, propranolol, acebutolol

  • Calcium Channel Blockers (BP med) - ex: amlodipine

    • Also: felodipine, isradipine, nicardipine

  • Statins (cholesterol med) - ex: atorvastatin

    • Also: lovastatin, simvastatin, fluvastatin, pravastatin

  • Proton Pump Inhibitors: (acid suppressing med) - ex: omeprazole

    • Also: pantoprazole, esomeprazole, lansoprazole

    • Common depletions: magnesium, B12

    • Possible depletions: maybe calcium and maybe iron

  • H2 Blockers: (acid suppressing med) - ex: cimetidine

    • Also: famotidine, ranitidine

bottom of page