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Drugs can be Prescription drugs which are medications that require a prescription from a healthcare provider such as a doctor or dentist. Drugs can also be recreational drugs such as marijuana, cocaine, heroin etc.


There are many different classes of drugs that are used to treat a wide range of medical conditions. Understanding the different drug classes and how they work can be essential for doctors in prescribing the most appropriate treatment for their patients.

Drug classes

One important drug class is the antimicrobials, which are used to treat infections caused by microorganisms such as bacteria, viruses, fungi, and parasites. Antimicrobials can be further classified based on their specific mechanism of action and the types of microorganisms they target. For example, antibiotics are a type of antimicrobial that specifically targets bacteria, while antivirals are used to treat viral infections.

Another important drug class is the analgesics, which are used to relieve pain. There are several different types of analgesics, including nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and opioids. Each type of analgesic works in a different way and may be more or less effective for different types of pain.

Other common drug classes include:

  • Cardiovascular drugs, which are used to treat conditions related to the heart and blood vessels, such as hypertension and coronary artery disease.
  • Central nervous system (CNS) drugs, which are used to treat conditions that affect the brain and nerves, such as epilepsy, anxiety, and depression.
  • Endocrine drugs, which are used to treat conditions related to the endocrine system, such as diabetes and thyroid disorders.
  • Gastrointestinal drugs, which are used to treat conditions related to the digestive system, such as acid reflux and inflammatory bowel disease.
  • Respiratory drugs, which are used to treat conditions related to the respiratory system, such as asthma and chronic obstructive pulmonary disease (COPD).

Side effects and interactions

It is important to note that each drug class has its own unique characteristics and potential side effects, and doctors must carefully consider these factors when prescribing medications for their patients. In addition, many drugs may interact with each other or with certain foods or supplements, and it is important for doctors to be aware of these potential interactions to minimize the risk of adverse effects.

DEA classification

Drugs, and substances are classified into five (5) distinct categories or schedules depending upon the drug’s acceptable medical use and the drug’s abuse or dependency potential.

Abuse potential

The abuse rate is a determinate factor in the scheduling of the drug; for example, Schedule I drugs have a high potential for abuse and the potential to create severe psychological and/or physical dependence. As the drug schedule changes-- Schedule II, Schedule III, etc., so does the abuse potential-- Schedule V drugs represents the least potential for abuse.

DEA Schedule I

Schedule I drugs, substances, or chemicals are defined as drugs with no currently accepted medical use and a high potential for abuse. Examples of Schedule I drugs are: heroin, lysergic acid diethylamide (LSD), marijuana (cannabis), 3,4-methylenedioxymethamphetamine (ecstasy), methaqualone, and peyote.

Schedule II

Schedule II drugs, substances, or chemicals are defined as drugs with a high potential for abuse, with use potentially leading to severe psychological or physical dependence. These drugs are also considered dangerous. Some examples of Schedule II drugs are: combination products with less than 15 milligrams of hydrocodone per dosage unit such as vicodin, cocaine, methamphetamine, methadone, hydromorphone (Dilaudid), meperidine (Demerol), oxycodone (OxyContin), fentanyl, Dexedrine, Adderall, and Ritalin

Schedule III

Schedule III drugs, substances, or chemicals are defined as drugs with a moderate to low potential for physical and psychological dependence. Schedule III drugs abuse potential is less than Schedule I and Schedule II drugs but more than Schedule IV. Some examples of Schedule III drugs are: products containing less than 90 milligrams of codeine per dosage unit (Tylenol with codeine), ketamine, anabolic steroids, testosterone

Schedule IV

Schedule IV drugs, substances, or chemicals are defined as drugs with a low potential for abuse and low risk of dependence. Some examples of Schedule IV drugs are: Xanax, Soma, Darvon, Darvocet, Valium, Ativan, Talwin, Ambien, Tramadol

Schedule V

Schedule V drugs, substances, or chemicals are defined as drugs with lower potential for abuse than Schedule IV and consist of preparations containing limited quantities of certain narcotics. Schedule V drugs are generally used for antidiarrheal, antitussive, and analgesic purposes. Some examples of Schedule V drugs are: cough preparations with less than 200 milligrams of codeine or per 100 milliliters (Robitussin AC), Lomotil, Motofen, Lyrica, Parepectolin

Comprehensive list of over 20,000 medications / pharmaceutical drugs sorted alphabetically. Please help add detailed information about each medication including their pharmacology, mechanism of action, indications, side effects, and other relevant information for each of these medications. Some of the useful resources for information including the Food and Drug Administration, Drug bank (Canada) and UK medicines info Also see the top 200 prescription drugs in US and drug classes.

List of pharmaceutical drugs/medications sorted alphabetically


Top 200 drugs | Medicare drugs | Canadian drugs | Dictionary of drugs | drug classes Comprehensive list of drugs sorted alphabetically in an A-Z list.

Encyclopedia of drugs

Encyclopedia of drugs | Dictionary of drugs

Popular drugs



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