Why is it bad to prescribe antibiotics for viruses?

[RedAlert]

I know that antibiotics have no effect against viruses, but why do many microbiologists often criticize doctors who do so, apart from the reason that I have given above?

[Dak]

Bacteria can pick up resistance to antibiotics, meaning that every time you prescribe them, you run the risk of making them inneffective.

 

The 'friendly' bacteria in your gut can pick up resiliance to the anti-biotic, and then pass the plasmid that contains the resistance to bacteria that infect you in the future.

[frostbite]

well another thing aside from developing resistance against the medicine is its spectrum of activity. lets take for example cefalexin. this cefalexin when taken is not like a heat-seeking missile that will only 'seek' its locked target. the medicine is like smoke that will engulf anything within the vicinity of infection. so that means even your lymphocytes trying to fight the infection. and if this will be applied to your statement, then your only killing your bacteria or worst -yourself. hehe!

[CharonY]

Bacteria can pick up resistance to antibiotics' date=' meaning that every time you prescribe them, you run the risk of making them inneffective.

 

The 'friendly' bacteria in your gut can pick up resiliance to the anti-biotic, and then pass the plasmid that contains the resistance to bacteria that infect you in the future.[/quote']

 

Not quite correct. They do not actvely pick up resistance genes in response to antiobiotics (at least not any more than they do anyhow). But while using ABs you select for them, thus increasing their numbers. Whereas under normal conditions the resistent ones would have to compete with the susceptible ones.

[walrusman]

Is this why you have to have a prescription? To control it better?

[badchad]

I went to the Dr. yesterday with a sore throat. The response I got was: "WEll, unfortunately the laboratory is closed today, but since you're throat looks a little swollen I'll give you this prescription anyway". Not the first time I've had this happen to me either.

 

Can anyone reference me some public health articles pertaining to antibiotic resistance? I understand the conceptual aspect, but have their been any epidemiological studies showing increases in antibiotic resistance or trends toward this?

[Immunologist]

In fact, your first observation that it is useless against viruses is quite sufficient in itself not to prescribe it.

Second, as noted, it favors the apparition of resistance. Usually, in a normal organism (human), a bacteria that mutated and is now resistant to antibiotics (yes, this occurs sporadicaly and naturally without presence of antibiotics) have it more as a burden than an advantage when there is no antibiotics. The use f antibiotics will provide it with an advantage and favors an improvement of this new strain by selecting the better ones. Thus, pretty bad for the rest of us.

Third, antibiotics kill many bacterias, not just pathogenic ones. Importantly, it will kill bacterias of the normal flora of the body and particularly the gut. This population is important and each antibiotic treatment affects them and rarely for the better. Among other things the normal flora prevents us from getting recurrent diarhea from opportunistic pathogens passing in the gut. If you trouble the normal flora, this could occur.

Althought Frostbite is correct in saying that antibiotics are not perfectly specific (I don't know about his precise example), they usually do not harm ourselves too badly and this argument, although probably true, would not be a major reason not to prescribe the antibiotic. Why?

 

Because we also have to concede that physicians have reasons to act this way: a viral infection could hide or allow a bacterial infection to occur as the immune system is occupied with the virus. So sometimes they prescribe the antibiotic in this idea, a risk that outweight the risk of non-specific killing of human cells (because often eucaryotic cells are sensitive to antibiotics, but to a concentration 2 or 3 logs higher than what is needed for bacterias)

 

Hope it helps!

[Drug addict]

Prescribing antibiotics for viral infections also exposes the patient to the side effects and interactions of the antibiotic. While the side effects may just be some nausea or diarrhoea, death (due to anaphylaxis) and pregnancy (due to OC failure) could occur.

[hgupta]

Besides what DAK and Drug Addict( ) posted, AB when prescribed for viral infections weakens your defense mechanism, thus making you prone to infections, and increases the rate of risk of the infection.

 

plus, an adult (assuming healthy) may not expose to side effects, but AB when given to children, old-aged people, pregnant women, increases that risk also. in most of the cases, these people do show some kind of abnormal behavior due to some dosage of ABs.