Why does medication have side effects

[nec209]

I know most all medication have side effects but why is that the case. I thought medication works similar to lock and key analogy it binds to that receptor. If that the case why do most all medication have side effects.

 

 

 

 

[Peterkin]

There are very many medications not aimed at specific antigens, viruses and bacteria. Researchers don't just design a molecule that you can ingest or inject; the active ingredient needs a stabilizing agent so it doesn't fall apart before it gets to the drug store, possibly some factor to neutralize a toxic component and it has to be attached to a vehicle, so it can be made into a pill or liquid. 

Even those that are antibiotic or anti-viral may also have ingredients that disagree with some people. No two metabolisms and medical histories are alike: there may be pre-existing conditions, allergies and sensitivities, changes in specific organs due to earlier illness and treatment... all kinds of different conditions.

Drugs designed to alleviate pain have to act through the digestive, circulatory and nervous systems. In a sense, all chemicals that do this are toxic to various extents. (That's a broad generalization, I realize.) If they're effective, they may also be addictive or acidic and therefore hard on the stomach. Drugs designed to correct an imbalance in hormone or enzyme production can't not affect the entire system of which their targeted organ is a part.  It's impossible to seperate systems in the human body. 

Basic reason: it's complicated.  

[CharonY]

It is because of biology. Even if a compounds specifically targets, say, a receptor and nothing else, inhibiting/blocking that receptor can have many effects. Some of these effects are beneficial in dealing with a disease, others may not.

Think about it that way: even in a single cell, the functions of molecules are interconnected. If you inhibit one enzymatic function, it has impact on many levels as up and down-stream pathways can be affected. Now increase the complexity from single cell to tissue, organ and organism and you have a host of non-target functions that will be impacted. Even if you eat things, you have a host of effect on your body, even if you do not think of it as medication.

 

6 minutes ago, Peterkin said:

Even those that are antibiotic or anti-viral may also have ingredients that disagree with some people.

Actually antibiotics are frequently disagreeable as they also interact with eukaryotic cells. Just not as fatally as with prokaryotic ones. Fluoroquinolone antibiotics for example can also interact with GABA-A receptors, for example. But as I said, even if they manage to find a  highly specific ligand, the interaction itself can kick off a plethora of other unintended effects.

The key for good medication is that it has a net benefit to the patient. It is exceedingly rare that some drug will have only one effect, even if you do not feel any symptoms. However, as long as there is a dosage where the primary issue is alleviated and the side effects are manageable it is a net benefit. But I don't think that we should think of drugs as highly specific agent that targets the source of a disease specifically. Rather, it is something that interacts with our biology on multiple level and hopefully during that course the issue is alleviated. That, of course depends on the mechanism and complexity of the disease to be treated, of course.

 

[LuckyR]

6 hours ago, nec209 said:

I know most all medication have side effects but why is that the case. I thought medication works similar to lock and key analogy it binds to that receptor. If that the case why do most all medication have side effects.

 

 

 

 

From a practical standpoint, the term "side effect" is somewhat arbitrary and depends in great measure on perspective. For example minoxidil was invented as a blood pressure medication, but later the "side effect" of increasing hair growth became the intended effect when the drug got FDA approval to treat baldness (at that point it's effect on blood pressure was a "side effect").

[Peterkin]

8 hours ago, LuckyR said:

From a practical standpoint, the term "side effect" is somewhat arbitrary and depends in great measure on perspective. For example minoxidil was invented as a blood pressure medication, but later the "side effect" of increasing hair growth became the intended effect when the drug got FDA approval to treat baldness (at that point it's effect on blood pressure was a "side effect").

That's scary. as someone with difficult-to-control blood pressure, i'm glad i have enough hair to be going on with. [sorry about cockroach style typing; i fell and bloke my left wrist. how does the aspirin know where the pain is [qm] It doesn't. i only hope it can also find the ones in my head and knee.   

[CharonY]

10 hours ago, LuckyR said:

From a practical standpoint, the term "side effect" is somewhat arbitrary and depends in great measure on perspective. For example minoxidil was invented as a blood pressure medication, but later the "side effect" of increasing hair growth became the intended effect when the drug got FDA approval to treat baldness (at that point it's effect on blood pressure was a "side effect").

I agree that side effects are a bit of misnomer. As I mentioned, any drug has a plethora of effects (though not necessarily symptoms) and it is basically convention to label effects that are not the intended purpose as side effect.

1 hour ago, Peterkin said:

That's scary. as someone with difficult-to-control blood pressure, i'm glad i have enough hair to be going on with. [sorry about cockroach style typing; i fell and bloke my left wrist. how does the aspirin know where the pain is [qm] It doesn't. i only hope it can also find the ones in my head and knee.   

Hope you are feeling better soon. With regard to broken bones, aspirin is anti-inflammatory and can help somewhat against inflammation-related pains (though it should do less against pain signals from the fracture itself, I would think). But on the downside, inflammation is apart of a signaling cascade related to healing processes. Based on that, there is the hypothesis that using too much aspirin could delay bone healing. But OTOH I think I saw a more systematic study on operation of some sort of fracture and no delayed healing was observed there (but I also don't recall what the age of the cohort was, as that would also play an outsized role).

Another related thought I forgot to add to my earlier post: for treatment, the medication ideally only targets the affected tissue/region. However, in most cases there is no way to achieve that relying instead on flooding the body with the medication in sufficiently high dosages so that the target region gets enough of the medication. That also means that non-target areas will be exposed to the drug and also affecting healthy tissue. Drugs are, generally speaking, not precision instruments.

 

 

[Peterkin]

3 hours ago, CharonY said:

Drugs are, generally speaking, not precision instruments.

no, but ain't we lucky to have 'em qm

aspirin is also blood thinner and sometimes hard on the stomach. i take a low dose one every day. for this pain, ibuprofen seems more effective - not too bad now. 

some side effects are more than inconvenient, some are life-threatening. much depends, too on how one's tolerance has been affected by treatments for previous conditions.   

[CharonY]

19 minutes ago, Peterkin said:

no, but ain't we lucky to have 'em qm

 

Obviously, though there are some folks who think that drugs somehow safer or less harmful than, say, vaccines.

20 minutes ago, Peterkin said:

aspirin is also blood thinner and sometimes hard on the stomach

Yes, and I think that there are some animal studies that suggested that thinning of the blood might play a role in improving blood flow and might improve healing (and potentially more than offset the disruption of inflammatory signaling). As you said, things are complicated.

 

22 minutes ago, Peterkin said:

some side effects are more than inconvenient, some are life-threatening. much depends, too on how one's tolerance has been affected by treatments for previous conditions.   

As well as other potentially unrecognized parameters that can interact with the drug in question. Sometimes in ways that we do not really understand.

For example, Aspirin has been identified as a risk factor for Reye's syndrome (mostly, but not exclusively in kids), typically in conjunction with viral infections.

[KJW]

One thing not already mentioned is the metabolism of the drug. For example, drugs are often metabolised by oxidation, and sometimes an oxidation product is toxic, a process called "toxication". One way pharmaceutical companies combat this problem is to make the drugs resistant to oxidation, typically by adding fluorine atoms to the molecule.

 

[CharonY]

Conversely, sometimes drugs are administered in a less active form (prodrugs) and are then metabolized into the active form. Beside oxidation there also many other metabolization pathways (codeine is demethylated to the more bioactive morphine, for example, but most glucuronidated, IIRC).