Drugs – 4 essential reads on how they are made, how they work and how context can make poisoning medicine


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(THE CONVERSATION) Pandemics and epidemics highlight the hurdles researchers face in getting a drug to the shelves. From finding potential drug candidates to balancing time and financial pressures while ensuring safety and efficacy, many aspects of drug development determine whether or not a treatment succeeds in emerging from the laboratory.

Expanding the definition of “drug” and where it can be found, however, could help broaden the therapeutic options available to researchers and patients.

Here are four facets of how drugs are developed and how they work in the body, taken from stories in the archives of The Conversation.

1. Match the drug to the target

The most effective drugs are, in a sense, the product of a good match – they bind to a specific pathogenic receptor in the body, cause a desired effect, and ideally bypass healthy parts of the body.

Drugs travel through the blood to reach their targets. For this reason, most drugs travel throughout the body and can bind to unintended sites, potentially causing unwanted side effects.

Researchers can increase the accuracy and effectiveness of a drug by designing different ways to take it. An inhaler, for example, delivers medicine directly into the lungs without having to travel through the rest of the body to get there.

It is also essential that patients take the medications as prescribed to ensure that the right dose gets where it needs to be often enough to have the desired effect. “Even with all the science needed to understand a disease well enough to develop an effective drug, it’s often up to the patient to make everything work as intended,” writes pharmaceutical scientist Tom Anchordoquy of the University of Colorado Anschutz.

2. Search for drug candidates

Researchers discovered a number of drugs by chance, including penicillin for bacterial infections, vaccines for smallpox, and warfarin for blood clots. While serendipity still plays a role in modern drug discovery, most drug developers take a systematic approach.

Scientists usually start by identifying a particular molecular target, usually receptors that trigger a specific response in the body. Then they look for chemical compounds that react with that target. The technology called high-throughput screening allows researchers to quickly test thousands of potential drug candidates at once. Compounds that meet the selection criteria progress to further development and refinement. Once optimized for their intended use, compounds are tested for safety and efficacy in animals and humans.

One way to facilitate the search for optimal drug candidates is to work with compounds that are already optimized to work in living things. Natural products, derived from organisms such as microbes, fungi, plants and animals, share similar structures and functions between species. Although not without their own development challenges, they could aid in the search for related compounds that work in humans.

“There are still thousands of microorganisms in the ocean to explore as potential sources of drug candidates, not to mention all on land,” writes medical chemist Ashu Tripathi of the University of Michigan. “In the search for new drugs to combat antibiotic resistance, natural products may still be the way forward.”

3. A drug by any other name can be just as effective

Existing drugs can find a second (or third, fourth and fifth) life through their repurposing.

Most drugs have many functions beyond what researchers originally designed them to do. While this multifunctionality is often the cause of unwanted side effects, sometimes these results are exactly what is needed to treat a completely unrelated condition.

Sildenafil, for example, failed to treat severe chest pain due to coronary heart disease, but was found to be potent in inducing erections like Viagra. Likewise, thalidomide, a compound that has caused birth defects in thousands of infants worldwide as a drug for morning sickness, has found redemption as a cancer treatment.

Because drugs inherently have more than one function in the body, repurposing existing drugs can help fill a gap where pharmaceutical companies and other developers cannot or will not. Gregory Way, a researcher at the University of Colorado at Anschutz, uses artificial intelligence to predict the various effects a drug can have and believes that this lack of specificity is something to be explored rather than ruled out. Instead of trying to focus on a specific target, he suggests that scientists “embrace the complexity of biology and try to take advantage of the multifaceted effects that drugs can offer.”

4. Poison as Medicine

If so many drugs can have toxic effects on the body, either through side effects or by taking the wrong dose or for the wrong condition, what determines whether a drug is a “drug” or a ” poison ” ?

Biomedical scientists evaluate drugs based on their active ingredient or a specific compound that has a specific effect on the body. But reducing drugs to a single molecule ignores another important factor that determines whether a drug is therapeutic: the context in which it is used. Opioids treat intractable pain, but can lead to debilitating and fatal addiction when misadministered. Chemotherapy kills tumors but causes collateral damage to healthy tissue in the process.

Another pharmaceutical paradigm, Traditional Chinese Medicine, has historically recognized the malleability of drugs through the use of poisons for therapeutic purposes.

Yan Liu, a medical historian at the University at Buffalo who studies the practice, notes that ancient texts did not distinguish between poisons and non-poisons — instead, Chinese physicians looked at drugs along a continuum. of power, or the ability to harm and heal. They used different processing and administration techniques to adjust the potency of the poisons. They have also taken a personalized approach to treatment, recognizing that each drug works differently depending on a number of different individual factors.

“The paradox of healing with poisons in traditional Chinese medicine reveals a key message: there is no essential, absolute, or immutable core that characterizes a medicine,” Liu writes. “Instead, the effect of any given drug is always relational – it depends on how the drug is used, how it interacts with a particular body, and its intended effects.”

Editor’s note: This story is a summary of articles from The Conversation archives.

This article is republished from The Conversation under a Creative Commons license. Read the original article here: https://theconversation.com/drugs-4-essential-reads-on-how-theyre-made-how-they-work-and-how-context-can-make-poison-a – medicine-192590.


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