Generality
Idiosyncrasy is a condition of hypersensitivity, or abnormal reactivity, towards different substances (foods, drugs, environmental pollutants, etc.) towards which the organism is intolerant. This state is neither induced nor accompanied by immunological phenomena, as happens, for example, in the case of allergy.
Regardless of the cause, idiosyncratic reactions occur with various types of clinical pictures (hives, rhinitis, nausea, diarrhea, difficulty breathing etc.), which sometimes prove to be lethal.
The most used therapy for the management of this pathological reaction is based on the administration of specific antagonist drugs.
What's this?
Idiosyncrasy is a particular predisposition of the organism to react abnormally, excessively and / or violently, when it comes into contact with a drug or certain substances, even if they are harmless. To be clear, the idiosyncratic reactions are different from those due to an overdose or to the side effects of the drugs, which manifest themselves with a certain regularity.
Idiosyncrasy and allergic reaction: what differences?
Although this reaction is typically negative, idiosyncrasy is not to be confused with an allergic phenomenon.
The substantial difference between the two manifestations is that the allergy is a reaction of the immune system to something that in some subjects is recognized as foreign, therefore it is attacked.
Idiosyncrasy is not attributable, however, to the immune system, but may depend on various pathogenetic mechanisms (such as congenital alterations of the enzymatic heritage, changes in the pharmacokinetic and pharmacodynamic equilibrium, etc.).
Causes
Idiosyncrasy a specific pathological reactivity of the organism to certain substances that, in normal subjects, are practically harmless. The phenomenon can derive from genetic factors or constitutional alterations, therefore proper to the patient.
Among the mechanisms most frequently involved in idiosyncratic reactions are:
- Excessive sensitivity to unchanged substances and / or their metabolites (as in the case, for example, of a drug);
- Lack / presence in the body of the subject of particular enzymes - such as G6PD or glutathione - that hinder the assimilation of the substance or react to contact with it.
idiosyncratic drug reaction
Pharmacosidemic is an abnormal reactivity of the organism to solid, liquid or gaseous drugs, normally well tolerated by the great majority of individuals. Unlike allergic reactions, idiosyncratic manifestations vary depending on the drug taken, can arise from the first administration and are dependent doses.
Risk factors
Idiosyncrasy is found with a higher incidence in women, compared to men.
Symptoms
Idiosyncrasy is manifested by an abnormal and exaggerated reactivity, for which the predisposed subjects manifest toxic symptoms or seizures characterized by: the contact with certain substances or the administration of drugs at therapeutic doses:
- General malaise;
- Nausea and vomit;
- Pallor;
- Fall in blood pressure;
- Breathing difficulty;
- Diffuse skin manifestations (urticaria).
Treatment and prevention
First of all, to control idiosyncratic reactions, it is necessary to know the substance to which one is vulnerable and the potential reactions associated with it, to intervene promptly from a therapeutic point of view. Therefore, it is necessary to eliminate the triggering factors and avoid a new contact.
If it is necessary to stop taking a drug, the transition to a different pharmacological class should be considered.
