Question: Are secondary effects the same in different animals ?

Anais Kahve answered on 9 Mar 2016:

Hello, this is a very interesting question but the answer is no. You might think that because all animals have a heart that all effects on the heart would be the same, but there are actually many differences between different animals. For example, when medicines are tested on animals, scientists have to be careful that the secondary effects seen in the animal won’t be seen in humans (assuming the medicine is intended for use in humans). For example, you mustn’t give a single molecule of paracetamol to a cat but you can give paracetamol to humans in higher doses. You must be wondering ‘why’ this is the case. It is down to the genetic differences of the animals. Different animals contain different types and different levels of enzymes to detoxify compounds like paracetamol. The enzymes that are needed to detoxify paracetamol aren’t present in the cat’s liver so the cat would die, but humans do have these enzymes. Since animals are used to determine how toxic drugs are before they are given to humans, just think how terrible it would be if paracetamol had only been tested on cats and on no other animal! If this had been the case then paracetamol would not be on the market.