Few people are aware of the vast amount of time and money invested in getting a drug from the laboratory to the drugstore shelf. Drugs undergo exhaustive testing before being approved for use by the general population, with the whole process often taking 10 to 12 years. It takes millions of dollars for a drug to reach the market, with more than half of the money being spent on clinical trials.
Early Development
Once a potentially useful drug has been identified in the laboratory, initial testing is usually done on animal models in order to assess for toxic effects. Once results from the initial testing are known, an application, known as the investigational new drug application, or IND, is submitted to the FDA for approval. Approval from the FDA means that the drug can then be tested on humans, a process referred to as clinical trials.
Clinical Trials
The aim of clinical trials is to determine both the effectiveness and toxicity of the drug. This is generally done in three phases. In phase I, the drug is tested on a small number of healthy volunteers. The main aim of this phase is to assess the level at which the drug becomes toxic. In phase II, the drug is then tested on larger numbers of volunteers with the target disease, not only to determine if the drug is effective but at what level it can be given with minimum side effects. In phase III clinical trials, the drug is tested on very large numbers of volunteers with the disease, comparing its effectiveness with existing medications or a placebo, which is a sugar pill that contains no medication.
FDA Review
Once the drug is considered safe and effective, a new drug application, or NDA, must be submitted to the FDA, detailing the results from the animal and human studies and all other relevant information associated with the drug such as dosage and product labelling. If the FDA approves, the drug then becomes available to the general population.
Postmarketing Surveillance
Also referred to as phase IV, postmarketing surveillance is the continuous monitoring of the drug after it has become available for widespread use. Postmarketing surveillance allows less common but significant side effects to be detected and reported to the FDA. If severe side effects occur, the FDA may withdraw the drug from the market. This was the case with Vioxx, an anti-inflammatory drug that was withdrawn from the market in 2004 due to an increased risk of heart attack and stroke.
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