About medicines – for dummies

How Medicines workElena Trubacheva, Clinical pharmacologist

ABC MagazineEvery time a person turns on the TV and sees an advertisement for medicines, he has a false feeling that the pill, like a magic bullet, flies exactly where it is needed.

Ignoring everything else. Unfortunately, that's not how pills work. But this is what pushes the development of pharmacology forward.

Let's figure out how drugs actually work. There are different mechanisms of action for different drugs.

Some work due to their special physico-chemical properties. For example, the well–known activated carbon is an adsorbent. If used correctly, of course (1 tablet per 10 kg of weight, grind and drink a glass of water).

The second – as blockers of transport systems in the body involved in the transfer of certain substances or enzymes. For example, verapamil is a calcium channel blocker.

But most drugs work on the principle of interaction of the active principle with certain proteins of our body, which are called receptors. They have an affinity for certain substances, and it is on this affinity that the action of drugs is built.

Different medications have different effects on the receptors. Some can activate receptors, and then they are called agonists. Others – to limit the activity of receptors, or even block it altogether. Such means are called antagonists.

Ideally, the drug molecule and the receptor should fit together like a key to a lock. In reality, this state of affairs is rare. And therefore analgin analgesics much weaker than narcotic drugs. It is because of the low affinity of the molecule to the receptor. From here, by the way, the legs grow and the side effects.

About the "side effect" in general, it is worth mentioning separately, because opening the annotation sheet enclosed in the medicine box, you can experience shock from the number of side effects of almost any drug. The fact is that absolutely all adverse reactions are recorded at the stage of clinical trials. They are also entered in the instructions. And it does not matter whether this trouble happened to one patient in several tens of thousands or to one in 10 million.

The safety of the drug is tested absolutely at all stages and a drug that gives a lot of life-threatening reactions will never reach the patient, no matter how effective it may be. Therefore, you should not expect the whole list of side effects at home. If you take the drug correctly, most likely, you will not have anything at all.

The development of adverse reactions depends on several reasons:

• Firstly, this is the dose of the drug, it must be strictly observed, because even Paracelsus said: "Everything is poison, and nothing is devoid of venom. The poison differs from the medicine in the dose." If you do not follow the dosage, then problems can begin. You don't have to go far for an example: paracetamol. It is included in almost all effervescent preparations for the treatment of colds. So, if you do not take into account the amount of paracetamol taken in fizz and additionally swallow it in the form of tablets or suspensions, you can inflict a significant blow to the liver. This will be a side effect caused by an overdose.
• Secondly, individual hypersensitivity of the body. Here, adverse reactions occur with a normal dosage of the drug. The only way to deal with such reactions is to remember, or better yet, write down all the drugs to which your body has reacted inadequately. And bring this list to the attention of the doctor who will treat you.
• Thirdly, the low specificity of the drug, when at normal dosage and normal sensitivity, a side effect is observed, since the drug acts non-specifically. A classic example is the long–term use of nonsteroidal anti-inflammatory drugs (diclofenac, ibuprofen, ketorol), which give a good analgesic effect, but at the same time affect the gastric mucosa and cause the formation of ulcers (so-called gastrotoxicity). Knowing this, doctors carry out the prevention of gastrotoxicity, but an independent long-term intake can lead to big stomach problems.

Controlled and predictable side reactions are the first and third. With a reasonable approach to treatment, they can be minimized or completely avoided. But the latter are unpredictable and uncontrollable. Therefore, all you can do in the second case is to inform your doctor about the problem as soon as possible.

Therefore, I would like to say once again: "medicines are not a toy for children" independent eating of medicines without taking into account their mechanism of action and possible adverse reactions is a very unsafe occupation. A doctor should prescribe medications. When they are really needed. Weighing all the pros and cons. Considering all possible risks and warning them as much as possible.

Portal "Eternal youth" http://vechnayamolodost.ru26.10.2010