Classification Of Drugs: Drug Types & PDF To Download

Summary: Drug classification is a system used to categorize controlled substances based on their medical use, potential for misuse, and risk of dependence. Under the federal Controlled Substances Act of 1970, the Drug Enforcement Administration (DEA) places drugs into five schedules — from Schedule I (highest restriction, no accepted medical use) to Schedule V (lowest restriction, accepted medical use with limited abuse potential). Beyond legal scheduling, drugs are also classified by their pharmacological effects: opioids, stimulants, depressants, and hallucinogens each carry distinct risks for addiction and withdrawal. Understanding how drugs are classified helps patients, families, and clinicians make informed decisions about treatment. At Overland IOP in Los Angeles, our outpatient addiction treatment programs address substance use disorders across all drug classifications through evidence-based therapy, medication-assisted treatment coordination, and relapse prevention planning.

Drugs can be grouped together in different ways – by the way they affect the body, how they are used or where they are prescribed and controlled. It’s valuable to understand the pharmacology classification of drugs, and specifically the risks and side effects. Additionally, it helps recognize addiction in loved ones. There is a wide range of substances, and unfortunately, more people struggle with substance use disorder every day. And, even though addiction is overwhelming, it is possible to find recovery.

What is the Purpose of Drug Classification?

The purpose of drug classification is to ensure drug use is safe and beneficial for the patient. Each time a drug is used, people’s body chemistry is changed. Drugs are meant to be helpful, but they can be harmful. Sadly, taking multiple drugs can change body chemistry so much it makes drugs less useful. Above all, it makes side effects more severe. That’s why it is vital to understand the pharmacology classification of drugs, and the risks and side effects.

Pharmacology Classification of Drugs By Chemical Similarities

Chemical similarities classify drugs because they often have the same impact and risks. A drug-dependent person is also likely to misuse drugs with chemical similarities. Additionally, chemically similar drugs often have the same effects in treatment:

• Alcohol

• Opioids

• Benzodiazepines

• Cannabinoids

• Barbiturates

Pharmacology Classification of Drugs Based on Effects

Different types of drugs affect people differently. Nonetheless, drugs may be categorized or classified according to certain shared symptomatologies or effects. For example, one drug makes a person energetic. However, another drug makes them relax.

• Central Nervous System (CNS) Depressants (slow down the operations of the brain and the body)

• Stimulants (accelerate the heart rate and elevate the blood pressure and “speed-up,” or over-stimulate, the body)

• Hallucinogens (cause the user to perceive things differently than they actually are)

• Dissociative Anesthetics (inhibit pain by cutting off or dissociating the brain’s perception of the pain)
• Narcotic Analgesics (relieve pain, induce euphoria, and create mood changes in the user)
• Inhalants (breathable substances that produce mind-altering results and effects)
• Cannabis (the scientific name for marijuana, includes cannabinoids and synthetics like Dronabinol)

Pharmacology Classification of Drugs by Legal Definition

In 1970 the federal government passed the Controlled Substance Act. It was in response to the drug epidemic. The Act establishes five pharmacology classifications of drugs or schedules.

The drug’s schedule is based on potential medical use, the potential for misuse, and addiction risk. But, international treaties are an exception. The U.S. must use certain drug classifications to comply with diplomatic agreements. These agreements include the Single Convention on Narcotic Drugs.

• Schedule V (the lowest penalties and few regulations. They have an acceptable medical purpose. And generally, the lowest risk of misuse and addiction)
• Schedule IV (the regulations and penalties for these drugs are a little more than Schedule V drugs. But, they have a low risk of misuse and addiction)
• Schedule III ( harsher penalties and more regulations than Schedule IV drugs. They have a low misuse rate and low to medium risk of addiction)
• Schedule II (The only pharmacology classification of drugs with more regulations and penalties than Schedule II drugs is Schedule I drugs. They have a high risk of misuse and severe addiction risk)
• Schedule I (Schedule I drugs are the most regulated and have the harshest penalties of all the drugs. They have a high risk of misuse and addiction)

Conclusion

This article provides a comprehensive overview of drug classification, emphasizing its significance in ensuring safe and beneficial drug use.

It discusses the categorization of drugs based on chemical similarities, effects on the body, and legal definitions under the Controlled Substance Act.

By understanding these classifications, the article aims to highlight the importance of recognizing addiction risks and side effects, thereby supporting more informed decisions in medical and recreational drug use.

FAQs About Classification Of Drugs

Q1: What are the five drug schedules under the Controlled Substances Act?

The Controlled Substances Act classifies drugs into five schedules based on accepted medical use, potential for misuse, and risk of physical or psychological dependence. Schedule I substances (such as heroin, LSD, and MDMA) have no currently accepted medical use and the highest potential for abuse. Schedule II substances (such as fentanyl, oxycodone, methamphetamine, and cocaine) have high abuse potential but accepted medical uses under strict regulation. Schedule III includes drugs like buprenorphine and anabolic steroids with moderate abuse risk. Schedule IV covers benzodiazepines like diazepam and alprazolam with lower abuse potential. Schedule V substances, such as cough preparations containing low-dose codeine, carry the lowest risk. Note that marijuana remains Schedule I federally, though its legal status varies by state.

Q2: What are the main types of drugs by pharmacological classification?

Drugs are also classified by how they affect the body and brain, independent of their legal schedule. The four major pharmacological categories are opioids (such as fentanyl, heroin, oxycodone, and morphine), which bind to opioid receptors to block pain and produce euphoria; stimulants (such as cocaine, methamphetamine, and prescription amphetamines), which increase dopamine and norepinephrine activity; depressants (such as benzodiazepines, barbiturates, and alcohol), which slow central nervous system activity; and hallucinogens (such as LSD, psilocybin, and PCP), which alter perception and cognition. Each class carries distinct patterns of dependence, withdrawal, and treatment needs, which is why individualized treatment planning is critical for effective addiction recovery.

Q3: What is the difference between drug classification and drug scheduling?

Drug scheduling is a legal classification system established by the Controlled Substances Act and enforced by the DEA. It determines how a substance is regulated, prescribed, and penalized under federal law. Drug classification in the broader pharmacological sense groups substances by their chemical properties and effects on the body — such as opioids, stimulants, depressants, and hallucinogens. A substance’s pharmacological class and its legal schedule do not always align. For example, both fentanyl (a Schedule II opioid) and heroin (a Schedule I opioid) belong to the same pharmacological class but are regulated very differently. Understanding both systems helps patients and families make sense of treatment options and legal implications.

Q4: Why is drug classification important for addiction treatment?

Drug classification directly informs how addiction treatment is designed and delivered. The pharmacological class of a substance determines withdrawal severity, medical detox protocols, medication-assisted treatment (MAT) options, and therapy approaches. Opioid use disorders, for example, may be treated with Schedule III medications like buprenorphine (Suboxone) or naltrexone, while benzodiazepine dependence requires carefully tapered medical detox due to the risk of life-threatening seizures. Stimulant use disorders currently have no FDA-approved medications, making behavioral therapies the primary treatment approach. At Overland IOP in Los Angeles, our clinical team uses drug classification knowledge to build individualized treatment plans that address the specific neurological and behavioral patterns of each substance class.

Q5: Can you get treatment for prescription drug addiction?

Yes. Prescription drug addiction is treatable and is one of the most common substance use disorders in the United States. The most frequently misused prescription drug classes include opioid painkillers (such as oxycodone, hydrocodone, and fentanyl), benzodiazepines (such as Xanax and Valium), and stimulants (such as Adderall and Ritalin). Treatment typically involves a combination of medical detox coordination, behavioral therapy (including CBT and DBT), medication-assisted treatment where appropriate, and relapse prevention planning. Outpatient programs like IOP and PHP allow individuals to receive structured treatment while continuing to manage work and family responsibilities. Overland IOP in Los Angeles treats prescription drug addiction as part of our comprehensive outpatient programs. Call (800) 530-3100 for a confidential assessment.

Q6: What is medication-assisted treatment (MAT) and how does it relate to drug schedules?

Medication-assisted treatment (MAT) uses FDA-approved medications in combination with behavioral therapy to treat substance use disorders, primarily opioid and alcohol use disorders. Several MAT medications are themselves controlled substances — buprenorphine (Suboxone) is Schedule III, while naltrexone (Vivitrol) is not a controlled substance. The scheduling of these medications determines how they can be prescribed and dispensed: buprenorphine requires specific prescriber certification, while naltrexone can be prescribed by any licensed physician. MAT has been shown to significantly reduce opioid overdose deaths, decrease illicit drug use, and improve treatment retention. Overland IOP coordinates MAT as part of our outpatient addiction treatment programs, working with prescribers to integrate medication management into each patient’s individualized plan.

Q7: Does Overland IOP in Los Angeles treat addiction across all drug classifications?

Yes. Overland IOP provides outpatient addiction treatment for substance use disorders involving opioids, stimulants (cocaine, methamphetamine), alcohol, benzodiazepines, prescription drugs, and co-occurring mental health conditions through our IOP and PHP programs in Los Angeles. Treatment includes individual therapy, group therapy, psychoeducation, medication management, relapse prevention, and coordination with medical detox providers when clinically indicated. Our evidence-based approach uses CBT, DBT, ACT, and psychodynamic therapy tailored to the specific substance class and each patient’s needs. Programs are available in-person (3415 Overland Ave) and virtually, with morning, afternoon, and evening tracks. We accept most major insurance plans. Call (800) 530-3100 to schedule a free consultation.