This document discusses various methods of classifying drugs. It describes the Anatomical Therapeutic Chemical (ATC) system used by the WHO to categorize drugs based on organ system, therapeutic effects, and chemical properties. It also outlines the US Drug Enforcement Administration's system of classifying drugs into 5 schedules based on their medical use, abuse potential, and dependence. Finally, it discusses pharmacological classification based on mechanism of action and therapeutic classification focused on therapeutic intent.

1. KNOW ABOUT YOUR DRUGS
PRESENTED BY
SANI SINGH
M. PHARM (PHARMACEUTICS)
DRUG
CLASSIFICATION

2.  Legal Classification
 Pharmacological Classification
 Therapeutic Classification

3.  Drugs are chemicals of low molecular masses that interact with
macromolecular targets and produce a biological response.
 A drug class is a term used to describe medications that are grouped
together because of their similarity.
 To ensure that use a drug safely to achieve the upmost benefit.
 It help to identify drug-drug interactions and the potential for drug
resistance and ensures the appropriate staging of treatment.
Drug Classification
Purpose of Drug Classification

4. Legal
Classification
Anatomical Therapeutic
Chemical (ATC)
Classification System
Controlled
Substance Act
(CSA)
Misuse of Drugs Act
USP Medicare
Model Guidelines
(USP MMG)

5. ATC Classification System
World Health Organization (WHO) created a multi-dimensional
system in 1976, called the Anatomical Therapeutic Chemical (ATC)
Classification System, which categorizes a drug based on 5 levels .
1. Level One describes the organ system the drug treats
2. Level Two describes the drug’s therapeutic effect
3. Level Three describes the mechanism/mode of action
4. Level Four describes the general chemical properties of the drug
5. Level Five describes the chemical components that make up the
drug (essentially the chemical name of the drug, such as finasteride
or ibuprofen)
 ATC/DDD Methodology: History’. World Health Organization Collaborating Centre
for Drug Statistics Methodology.
 World Health Organization (2003). Introduction to drug utilization research. Geneva:
WHO. p. 33.

6.  The ATC system is able to classify the active ingredient of a drug
under a strict hierarchy so that it is appropriately used and not mistaken
for another drug.
 It controlled by the World Health Organization Collaborating Centre
for Drug Statistics Methodology (WHOCC).
 The drugs are divided into 14 main groups in 1st level.
 2nd, 3rd and 4th level are often used to identify pharmacological
subgroups when that is considered more appropriate than therapeutic or
chemical subgroups.

7. • Alimentary tract and metabolismA
• Blood and blood forming organsB
• Cardiovascular systemC
• Dermatologicals
• Systemic hormonal preparations, excluding sex hormones and insulins
• Antineoplastic and immunomodulating agents
• Anti-infectives for systemic use
• Genito-urinary system and sex hormones
D
E
H
J
• Musculo-skeletal system
• Antiparasitic products, Insecticides and repellents
• Nervous system
• Veterinary drug
L
M
P
N
Q
R
S
• Respiratory system
• Sensory organs
14 main groups in level 1st

8.  The complete classification of Metformin illustrates the structure of
the code according to ATC system :
A - Alimentary tract and metabolism (1st level, anatomical main group)
A10 – Drugs used in diabetes (2nd level, therapeutic subgroup- consists of
two digits)
A10B – Oral blood glucose lowering drugs (3rd level, pharmacological
subgroup)
A10BA – Biguanides (4th level, chemical subgroup)
A10BA02 – Metformin (5th level, chemical substance)
 Thus, in the ATC system all plain Metformin preparations are given the
code A10BA02.

9. US Legal Classification
 The Federal Government passed the Controlled Substance Act
(CSA) in 1970. This act established 5 drug classifications, or
schedules, for drugs regulated by law.
 According to the U.S. Drug Enforcement Administration (DEA),
substances from any of these classes may lead to development of
chemical dependence in one or both of the following forms:
1. Physical dependence
2. Psychological dependence
 According to the DEA, these classifications are broken down based on
their potential for abuse and if they have a legitimate medical use .
 An updated and complete list of the schedule is published annually in
Title 21 Code of Federal Regulations (C.F.R.) 1308.11 through
1308.15.

10. It include the drugs that have a high potential for abuse, that have no
currently accepted medical use in treatment, and that there is a lack of
accepted safety for use of the drug under medical supervision.
• Examples – Cannabis, Heroin, Ecstasy, Mescaline, LSD, GHB, and
Methaqualone.
Schedule I
Schedule II
It includes drugs that have high potential for abuse, have currently
accepted medical use in treatment or currently accepted medical use
with severe restrictions, and the abuse of may lead to severe
psychological or physical dependence.
• Examples- Amphetamine, Cocaine, Fentanyl, Hydromorphone
oxycodone, and Hydrocodone.

11. Schedule III
It includes drugs that have a potential for abuse less than the drugs or other
substances in schedules I and II, have a currently accepted medical use in
treatment, and that the abuse of may lead to moderate or low physical
dependence or high psychological dependence.
• Examples- Anabolic Steroids, Buprenorphine, and Ketamine.
Schedule IV
It includes drugs that have a low potential for abuse relative to the drugs or
other substances in schedule III, have a currently accepted medical use in
treatment, and that the abuse of may lead to limited physical dependence or
psychological dependence relative to the drugs or other substances in
schedule III.
• Examples-Benzodiazepines, Modafinil, and Tramadol.

12. Schedule V
It includes drugs that have a low potential for abuse relative to the
drugs or other substances in schedules IV, have a currently accepted
medical use in treatment, and that the abuse of may lead to limited
physical dependence or high psychological dependence relative to the
drugs or other substances in schedule IV.
• Examples-Diphenoxylate (in combination with atropine),
Lacosamide, and Pregabalin.
 https://www.law.cornell.edu
 https://medshadow.org

13. UK Legal Classification
 Drugs controlled by the United Kingdom (UK) Misuse of Drugs Act
1971. These drugs are known in the UK as controlled drugs.
 This act sets out 3 separate categories are –
 Class A
 Class B
 Class C

14. Class A
Drugs
• Opioid
• Tryptamine
• Stimulant
• Ergoline
• Phenethylamine
• Methadone
Class B
Drugs
• Cannabinoid
• Sedative
• Hallucinogen
• Amphetamines
• Barbiturates
• Codeine
Class C
Drugs
• Benzodiazepine
• Nonbenzodiazepine
(Zaleplon, Zolpidem,
and Zopiclone)
• Anabolic Steroids
• Chorionic
Gonadotropin
• Non-human chorionic
Gonadotrophn
 “Misuse of Drugs Act 1971 (c.38): Schedule 2: Controlled Drugs” .
 www.legislation.gov.uk

15. USP Drug Classification
 USP has developed and updated the USP Medicare Model Guidelines (USP
MMG) since 2004, under the Medicare Prescription Drug Improvement and
Modernization Act (2003), Section 1860D-4(b)(3)(C)(ii).
 The USP DC utilize pharmacotherapeutic evidence within the context of FDA-
approved indications for placing example drugs.
 A drug in the associated list may appear in more than one USP Category or USP
Class if there is a scientifically valid and clinically meaningful patient care issue.
 In total, the USP Medicare Model Guidelines v7.0 has:
 48 USP Categories
 154 USP Classes
 169 Unique USP Categories or Classes
 2 renamed Categories, 4 new classes and 5 renamed Classes
USP Categories and Classes

16. USP Medicare Model Guidelines v1.0-v7.0
V1.0
(2005)
V2.0
(2006)
V3.0
(2007)
V4.0
(2008)
V5.0
(2011)
V6.0
(2014)
V7.0
(2017)
USP Categories 41 49 50 50 50 49 48
USP Classes 137 117 119 119 146 151 154
Unique
Categories and
Classes *
133 133 138 138 161 167 169
Formulary Key
Drug Types -
Total
141 141 193 192 Retired Retired Retired
* Unique Categories and Classes is the sum of the number of USP Classes and the
number of USP Categories that have no associated classes.

17. From the broadest perspective, the USP currently categorizes a drug or drug
component under one of 49 different therapeutic classes are –
• Analgesic, including opioids and non-opioids
• Anesthetics
• Antibacterials, including antibiotics
• Anticonvulsants
• Antidementia agents
• Antidepressants
• Antidotes and antitoxins
• Antiemetics
• Antifungals
• Anti-inflammatory agents, including corticosteroids and nonsteroidal anti-
inflammatory drugs (NSAIDs)
• Antimigraine agents
• Antimyasthenic agents
• Antimycobacterials

18. • Antineoplastics
• Antiparasitics
• Antiparkinson agents
• Antipsychotics
• Antiviral, including HIV antiretrovirals and direct-acting hepatitis C drugs
• Anxiolytic (Anti-anxiety ) agents
• Bipolar agents
• Blood glucose regulators, including insulin and other diabetes medications
• Blood products, including anticoagulants
• Cardiovascular agents, including beta blockers and ACE inhibitors
• Central nervous system agents, including amphetamines
• Dental and oral agents
• Dermatological (skin) agents
• Enzyme replacement agent
• Gastrointestinal agents, including H2 blockers and proton pump inhibitors
• Genitourinary (genital and urinary tract) agents

19. • Hormonal agents (adrenal)
• Hormonal agents (pituitary)
• Hormonal agents (prostaglandins)
• Hormonal agents (sex hormones), including estrogen, testosterone, and
anabolic steroids
• Hormonal agents (thyroid)
 https://www.usp.org
 https://www.verywellhealth.com

20. Pharmacological Classification of Drugs
 It describes a drug’s properties in specific way.
 It based on mechanism of action and includes only those drugs that
have similar mechanism of action.
Pharmacological
Classification
• Autonomic Nervous System Drugs
• Gastrointestinal Drugs
• Cardiovascular Drugs
• Urological and Related Drugs
• Respiratory Drugs
• Central Nervous System Drugs
• Analgesics, Anti-Inflammatory and Anti-Pyretic Drugs
• Drugs used in Disorders of the Ear, Nose and Oropharynx
• Drugs used in Anaesthesia
• Drug Used in Muscloskeleton and Joint Disease
• Anti-Infectives

21. PharmacologicalClassification
• Drugs used in Endocrine Disorders and Contraceptives
• Obstetric and Gynecological Medications
• Antineoplastic and Adjuvants
• Blood Products and Drugs
• Vitamins
• Drugs for Correcting Water Electrolyte and Acid-Base
Disturbances
• Antihistamines and Antiallergics
• Ophthalmic Agents
• Dermatological Agents
• Antidotes and Other Substances used in Poisoning
• Immunological Preparation
• Vaccines and Related Products

22. Therapeutic Classification of Drugs
 Therapeutic Classes are broad categories based on therapeutic intent.
 Drug grouped by therapeutic class work in very different ways-
 They are not chemically similar
 They have different mechanisms of action
Gastrointestinal Drugs
• Proton Pump Inhibitors
• Histamine (H2) Receptor
Blockers
• Diarrhea and Ulcerative Colitis
• Laxatives
• Nausea
Renal Drugs
• Renal Medications
• Erythropoiesis-Stimulating
Agents (ESAs)

23. Cardiovascular
Drugs
• Beta Blockers
• Renin-Angiotensin-
Aldosterone System
(RAAS)
• Calcium Channel
Blockers (CCBs)
• Diuretics
• Statins
• Other Agents for
Dyslipidemias
• Antiplatelets
• Traditional
Anticoagulants
• Novel Oral
Anticoagulants
(NOACs)
• Antianginals
Neurological
Drugs
• Headache
• Epilepsy
• Opioid Analgesics
• Non-Steroidal Anti-
Inflammatory Drugs
(NSAIDs)
• Muscle Relaxants
• Adjunct Medications
for Pain
• Alzheimer’s Disease
• Smoking Cessation
Psychiatric Drugs
• Atypical Antipsychotics
• Benzodiazepines
• Selective Serotonin
Reuptake Inhibitors
(SSRIs)
• Serotonin-
Norepinephrine
Reuptake Inhibitors
(SNRIs)
• Non-Benzodiazepine
Hypnotics
• Tricyclic
Antidepressant
• Anti-Anxiety Agents
• Stimulants and
Attention Deficit
Hyperactivity Disorder
(ADHD) Agents

24. Respiratory Drugs
• Inhaled Corticosteroids
and Long-Acting Beta
Agonists
• Short-Acting Beta
Agonists and
Anticholinergics
Endocrinology
Drugs
• Oral Diabetic Agents-l
• Oral Diabetic Agents-ll
• Injectable Diabetic Agents
• Contraceptives
• Corticosteroids
• Hormonal Therapy
Rheumatologic
Drugs
• Osteoporosis
• Rheumatoid Arthritis
• Gout

25. Urologic Drugs
• Benign Prostatic Hypertrophy- Alpha
Blockers
• Benign Prostatic Hypertrophy- 5-
Alpha Reductase Inhibitors
• Erectile Dysfunction
• Overactive Bladder
Ophthalmic and
Otolaryngological
Drugs
• Allergies
• Nasal Corticosteroids
• Cough and Cold
• Glucoma

26. Infectious Disease Drugs
• Antibiotics- Beta-Lactams
• Antibiotics- Fluoroquinolones
• Antibiotics- Macrolides
• Triazole Antifungals
• Antivirals- Influenza and Herpes Simplex
• Antivirals- Human Immunodeficiency Virus (HIV)

27. References
1. ATC/DDD Methodology: History’. World Health Organization Collaborating Centre
for Drug Statistics Methodology.
2. World Health Organization (2003). Introduction to drug utilization research.
Geneva: WHO. p. 33.
3. www.verywellhealth.com
4. https://www.usp.org
5. https://medshadow.org
6. “Misuse of Drugs Act 1971 (c.38): Schedule 2: Controlled Drugs”
7. www.legislation.gov.uk
8. https://www.law.cornell.edu
9. http://clincalc.com/academy
 Detail study of Legal Classification, visit official website of
respective regulatory authority or guidelines.

28. Thanks You