What are Antibiotics
The term "antibiotics" commonly refers to all those substances that can kill bacteria ( bactericidal drugs) or stop their growth ( bacteriostatic drugs).
However, the term antibiotic - even if wrongly - is used by most to indicate bacteriostatic or bactericidal substances, both of natural origin and of synthetic origin.
Side effects
Since the first antibacterial drugs were discovered, research in this area has continued to develop, leading to the synthesis of numerous new classes of antibiotic drugs.
Within each class there are different molecules, which can differentiate one from the other for very small structural variations. These variations - although minimal - can have a great impact on the action spectrum and on the side effects induced by the drug itself.
Antibiotics, therefore, can trigger multiple adverse effects - from the most mild to the most severe - depending on their chemical structure, the way they act and the type of microorganism to be counteracted.
Furthermore, the variability in response to the antibiotic therapy that exists between one patient and another must also be borne in mind. In fact, it is said that the side effects do not occur - or all occur with the same intensity - in each patient, since each person has his own sensitivity to each drug.
For all these reasons, we cannot talk about side effects common to all antibiotic drugs.
However, there are some types of adverse effects that can occur during treatment with most antibiotic drugs. These effects are mainly related to the interaction of antibiotics taken with the rich bacterial flora (or human microbiota ) that populates our body.
Alterations of the endogenous bacterial flora
The human body lives in symbiosis with the microorganisms that constitute its bacterial flora; it is therefore a close relationship based on obtaining reciprocal advantages: the organism supplies the "own" microorganisms with the nutritional elements necessary for survival and they - in return - protect it from foreign and pathogenic micro-organisms, preventing it from colonizing it and infect it.
Any alteration of this delicate balance - due, for example, to the intake of antibiotics - can lead to the onset of harmful effects on the organism itself.
Antibiotics can kill - or at least alter the balance - of bacteria naturally present in the gastrointestinal tract, in the respiratory tract, in the oral cavity, in the genital organs and on the skin.
An example is the undesirable effects on the gastrointestinal tract induced by many antibiotics. These effects include nausea, vomiting and diarrhea.
This last adverse effect is due to the alteration of the balance of the intestinal bacterial flora; in fact, it is not unusual for the doctor - together with antibiotic therapy - to prescribe a treatment based on lactic acid bacteria.
Another side effect due to the alteration of the intestinal bacterial flora is vitamin deficiency, caused by the killing of the bacteria responsible for the synthesis of the vitamins themselves. Generally, this drawback can be overcome with the administration of vitamins.
The alteration of the bacterial flora in the body can also favor the uncontrolled proliferation of microorganisms that are not sensitive to the antibiotic administered, such as resistant bacteria and fungi.
Some of these microorganisms - normally present in the body's bacterial flora - can become harmful and very dangerous if they proliferate without control or if they migrate to areas of the body other than those in which they normally live.
An example is that of Candida albicans and other fungi belonging to the same genus. Candida albicans is a saprophytic fungus that lives in the oral cavity, in the intestinal mucosa and in the mucous membranes of the genitals of many healthy individuals. In these individuals, the immune system is able to control this fungus and prevent it from proliferating excessively by becoming pathological. However, following antibiotic therapy - especially if long-lasting - the saprophytic fungus can take over and proliferate uncontrollably, thus becoming pathological and giving rise to the so-called candidiasis.
Allergic reactions
Another side effect that all antibiotics may share - but which, in reality, can occur with any drug or any other foreign substance administered - is the onset of allergic reactions in sensitive individuals.
Allergic reactions can be both mild and severe.
Generally, mild allergic reactions occur in the form of cutaneous manifestations that - usually - do not require drug treatment.
In severe allergic forms, on the other hand, fever, leukopenia, aplastic anemia, angioedema and / or anaphylactic shock may occur.
Toxicity and specific side effects
As mentioned above, there are numerous and different antibiotics that can cause as many different and different side effects.
Some classes of antibiotics, however, possess a "typical" toxicity towards certain organs or tissues, or they cause specific side effects for the same class to which they belong.
This is the example of the ototoxicity induced by aminoglycoside antibiotics or photosensitivity reactions typical of the tetracycline class.
Contraindications
Regarding the contraindications of antibiotics, the speech is similar to that already made for the side effects. In fact, each class of antibiotics and each antibiotic has different contraindications.
Some contraindications may depend on the type of infection you intend to treat, the age of the patient, his clinical conditions and the presence or otherwise of other diseases. Furthermore, an antibiotic may be contraindicated in patients who have already undergone other pharmacological treatments, as there may be interactions between drugs that can be very dangerous.
The only contraindication common to all antibiotics is that in which the patient has a known hypersensitivity to the active ingredient or to other active ingredients belonging to the same class of antibiotics.
