The dose makes the poison

Dosis facit venerum.

Those words came from a man named Paracelsus (1493-1541), who was also recognized as the founder of toxicology. That sentence, which means “the dose makes the poison”, wants to tell us that every existing substance may be harmful if dosed too high.

This principal applies to most of the drugs, which exist nowadays. A really low dose may give a no-effect. If it’s dosed higher, it may give a beneficial and non-toxic effect. But if the dose is too high, it will be toxic and may become lethal for the people.

Try to think about what has been happening in our world. Human can never live without water. It’s needed to fulfill our need of fluid, for the plants to grow, to wash dishes, etc. But what will happen if the amount multiplied so suddenly. Yes, a “high dose” of water will lead to flood like what happened so recent in UK and Indonesia. Fire, which is useful to be used for cooking, will not be so useful anymore if you encounter it in a burnt house.

A simple example from the biomedical area is alcohol. This can be shown by checking the dose, which are represented by ethanol percentage measured in blood, which gives following numbers: 0,05% (non-toxic dose); 0,1% (toxic dose) and 0,5% (lethal dose). Thus, a difference of 0,05% differentiates alcohol from its beneficial function to lower the risk of cardiovascular disease, reduce the risk of gallstones, etc. and its another function as a “killer” by increasing the burden of liver and even posing dangerous effect for cardiovascular system and brain.

This thought has made the current development of drugs being strict controlled and regulated. A correct dosing has to be made and calculated. A too low dose will give no or only a little bit of effect, while a too high dose can be dangerous for the patient or may be lethal. That’s why, nowadays a drug development has to undergo pre-clinical and clinical trials, often including post-clinical phase, which can make a total of 10-20 years, as to lessen the risk of the compound being dangerous to people.
Although, unwanted and undesired incidents can still happen despite of all the safety measurements taken to prevent and avoid it.