15 Drug Classes You Need to Know

drug classes to know


As part of your pharmacy exam, you are expected to understand the fundamentals of medicine. This includes drug classes. Below, we’ve put together a range of drug classes – and some examples of each – that you need to know.

Most drug classes are widely known, and their function is clear. When we hear of “antihypertensive drugs”, we understand its purpose. That said, it’s often valuable to go back to basics to ensure we really understand the purpose of each drug class.

Take “sedative” and “hypnotic”, for example.

Though these drug classes have different clinical roles, it’s not uncommon to hear these terms used interchangeably – as if they mean the same thing. True, they have overlapping functions but, individually, there is a clear distinction.

Sedatives are medicines whose purpose is to relieve anxiety / stress. Hypnotics are medicines that induce and prolong sleep.

Some drugs are therefore classified as sedative-hypnotics, because the medicine carries a dual role. Benzodiazepines, for example, have both sedative and hypnotic effects. It’s important to bear this type of distinction in mind.

We’ve also included other important distinctions – such as the difference between a “diuretic” and an “aquaretic”, and the difference between an “expectorant” and a “mucolytic”, among others.

Though these details are somewhat small, it’s vital that you do not overlook them. You can expect NAPLEX practice questions on topics such as this. Taking a few minutes to revise these fundamental details can, therefore, go a long way.

Must-Know Drug Classes

Below, we’ve put together 15 must-know drug classes – some of which are obvious, some not so obvious. It’s important not to miscategorise a medicine.

Drug Class Example(s) Function
Anorectic Bupropion/naltrexone Drug that reduces appetite
Orexigenic Olanzapine




Drug that stimulates appetite
Antitussive Codeine


Drug that suppresses cough
Expectorant Guaifenesin Enhances mucus production
Mucolytic Carbocisteine



Thin viscous / excessive mucus production
Antipyretic NSAIDs



Drug that reduces fever
Aquaretic Tolvaptan Drug that promotes water loss but not electrolyte loss
Diuretic Furosemide



Drug that promotes both water and electrolyte loss
Nootropic Caffeine



Enhance cognitive function
Eugeroic Modafinil


Wakefulness-promoting drug
Soporific Benzodiazepines


Hypnotic / sleep induction
Sedative Alcohol


Cerumenolytic Hydrogen peroxide Ear wax softener
Antipruritic Antihistamines



Local anesthetics

Anti-itch agent
Pediculicide Permethrin Drugs that treat lice

Register Today for More!

To fully prepare for the needs and demands of your clinical pharmacy exam, you need to practice pharmacology quiz questions and answers. The more you try, the better your performance on exam day.

We’ve put together a comprehensive range of 2,500+ NAPLEX questions to help you master your next test. Our question bank is complete, detailed and offers the type of explanatory answer that reinforces your learning – day in, day out.

NAPLEX Study Guide is the leading online program that teaches you the clinical details you need to know about drugs and medicines. Return to our NAPLEX blog soon for more great articles on drug classes and mechanisms of action.


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