What Is ELI5 : How do governments decide which drugs can be sold in pharmacies (even if they have risks) versus which ones are illegal

Overview

Understanding how governments decide which substances can be sold in pharmacies and which remain illegal can seem complex, especially when many legal drugs carry significant risks. This process is primarily driven by a balance between potential medical benefits and the risks associated with a substance, including its potential for abuse and harm. Regulatory bodies worldwide, guided by scientific research and public health objectives, establish frameworks to evaluate and control drugs.

The Regulatory Landscape: Approval and Control

The journey of a drug from discovery to being available in a pharmacy is long and highly regulated. In the United States, the primary agency responsible for approving drugs for sale is the Food and Drug Administration (FDA). The FDA's mandate is to ensure that drugs are safe and effective for their intended use. This involves a multi-stage process:

Drug Development and Pre-Clinical Testing

Before a drug can even be tested in humans, it undergoes extensive pre-clinical research. This involves laboratory studies and animal testing to assess its basic safety and biological activity. Researchers gather data on how the drug is absorbed, distributed, metabolized, and excreted by the body, as well as its potential toxicity.

Clinical Trials: Human Testing

If pre-clinical studies show promise, the drug developer submits an Investigational New Drug (IND) application to the FDA. If approved, the drug can enter clinical trials, which are conducted in humans in three main phases:

• Phase 1: Involves a small group of healthy volunteers (20-80) to assess safety, determine a safe dosage range, and identify side effects.
• Phase 2: Involves a larger group of patients (several hundred) who have the condition the drug is intended to treat. This phase aims to evaluate the drug's effectiveness and further assess its safety.
• Phase 3: Involves a large, diverse group of patients (several hundred to several thousand) across multiple study sites. These trials confirm the drug's effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug to be used safely.

FDA Review and Approval

Once clinical trials are successfully completed, the drug sponsor submits a New Drug Application (NDA) to the FDA. The FDA then conducts a thorough review of all submitted data, including manufacturing information, to determine if the drug is safe and effective for its proposed use. If the benefits of the drug outweigh its known risks, the FDA may approve it for marketing.

Controlling Potentially Abusive Substances: The Controlled Substances Act

While the FDA focuses on safety and efficacy for medical use, another critical aspect of drug regulation involves substances with a high potential for abuse and addiction. In the U.S., this is primarily managed under the Controlled Substances Act (CSA), administered by the Drug Enforcement Administration (DEA).

Drug Scheduling

The CSA categorizes drugs into five schedules (Schedule I through V) based on their:

• Potential for abuse: How likely the drug is to be misused.
• Accepted medical use: Whether the drug has a currently accepted medical use in treatment in the United States.
• Abuse or dependence potential: The likelihood of a drug causing physical or psychological dependence.

Schedule I drugs have a high potential for abuse, no currently accepted medical use in treatment in the U.S., and a lack of accepted safety for use under medical supervision. Examples include heroin and LSD.

Schedule II drugs also have a high potential for abuse, but they have a currently accepted medical use, though abuse may lead to severe psychological or physical dependence. Examples include cocaine, methamphetamine, and oxycodone.

Schedules III, IV, and V represent drugs with progressively lower potential for abuse and dependence, while still having accepted medical uses. Examples include ketamine (Schedule III), alprazolam (Schedule IV), and cough preparations containing codeine (Schedule V).

The Risk-Benefit Analysis

The fundamental principle guiding these decisions is a risk-benefit analysis. For a drug to be approved for sale, its potential medical benefits must be judged to outweigh its potential risks. This is why many potent medications, such as opioids or powerful sedatives, are available by prescription only. Their significant therapeutic value is recognized, but their potential for abuse and dangerous side effects necessitates strict medical supervision and control.

Illegal Drugs: No Accepted Medical Use and High Abuse Potential

Substances designated as illegal are typically those that have been determined to have no accepted medical use in the United States and a high potential for abuse. Even if a substance has some reported or theoretical medical applications, if its abuse potential is deemed too high and its safety profile too risky for general use, it may be classified as illegal.

International Considerations

Drug control is not solely a national issue. International treaties, such as the UN Single Convention on Narcotic Drugs (1961) and the Convention on Psychotropic Substances (1971), aim to establish global standards for drug control. These agreements require signatory nations to implement controls on specific substances, influencing national legislation and regulatory approaches.

Conclusion

In essence, governments grant access to drugs through pharmacies based on a rigorous scientific evaluation of their safety and efficacy for treating medical conditions. Simultaneously, they prohibit or strictly control substances with high abuse potential and no accepted medical use to protect public health. This dual approach aims to maximize the therapeutic benefits of medicines while minimizing the harms associated with drug abuse and diversion.