Before a prescription medication is available for public use, it goes thru numerous testing and trials. Understanding this process is extremely important in this time of Covid.
I will try to explain how a chemical compound goes from “discovery” to being available in the pharmacy.
Chemical compound is discovered:
Researchers in universities, drug companies, or in privately owned labs are constantly searching for or creating new compounds in their laboratories. In recent years, many of these compounds are “custom” made.
The researchers first identify certain chemical properties which might be useful for a specific disease or condition. They then try to create chemical compounds which have the needed chemical properties. Many times, hundreds of chemical compounds are created to find the one compound that contains all the necessary properties. Once a specific chemical compound is identified, it is then tested for safety in small animals (such as mice).
If the researcher feels the chemical is safe in small animals and has the potential for being a safe and effective treatment in humans, the chemical compound then proceeds to “clinical trials.”
Creating, searching, identifying a potential chemical compound takes numerous years, and hundreds of millions of dollars.
To assess the safety and efficacy of a chemical compound, it must be tested in humans before it is available in the pharmacies. Clinical trials are research studies performed in people that are aimed at evaluating the safety and effectiveness of a medical treatment.
There are 4 phases of clinical trials.
Phase 1 – uses the proposed chemical compound on a very small group of HEALTHY people (20 – 80) to judge its safety and side effects, and to find the correct dosage. These trials usually last a few months.
Phase 2 – uses more people (100 – 300) to obtain preliminary data on whether the drug is effective in people with a certain disease or condition. While the emphasis on Phase 1 is on safety, the emphasis on Phase 2 is on effectiveness. These trials continue to study safety, including short term side effects, and can last several years.
Phase 3 – uses a large number of patients (500 – 3000), studying different populations and different dosages, to gather detailed information about safety and effectiveness. These trials can take several additional years.
Once the results are analyzed from the Phase 3 trials, the drug company submits all the data, and their intended use, to the FDA. If the chemical compound is not effective, or if the side effects are too dangerous, the medication is dropped and it is never reviewed by the FDA.
If the FDA agrees that the trial results of favorable, with acceptable side effects, it will approve the experimental drug.
Only after the FDA approves the medication can the drug be prescribed by your physician and used by the general public.
Phase 4 – takes place AFTER the FDA approves the medication. In a phase 4 trial, the safety and effectiveness are monitored in large, diverse populations. Many times, the side effects of a drug may not become clear until more people have taken the medication over a longer period of time.
- Sudhir S. Athni, MD