Contrary to what we are used to thinking, an allergy reaction does not occur the first time a drug is taken. In order to develop an allergy reaction, it is necessary for the immune system to prepare and develop the response to cope with the drug. That is why an allergic reaction to a product can occur from the second contact with it, although it is a mistake to think that if a medicine has been consumed frequently and has never been bad for us, we will never have an allergic reaction to it.
What most determines an allergy to medicines is repeated contact with them, in addition to other factors such as genetic antecedents or having other allergies. The greater the consumption of medications, the greater the possibility of having an allergic reaction. Non-steroidal anti-inflammatory drugs (such as Ibuprofen), beta-lactam antibiotics (such as Penicillin) or iodinated contrast agents, among others, are the most allergenic drugs known to us.
Dangers and treatment
The most dangerous allergic reaction is anaphylaxis, which affects two or more organs and progresses rapidly, putting people’s lives at risk. Other frequent reactions are angioedema, urticaria, digestive symptoms, respiratory symptoms such as asthma and rhinitis.
In case of allergic reactions, the patient should undergo alternative treatments. Those allergic to beta-lactams should switch to other groups of antibiotics with the same spectrum of action and for the same bacteria. Those allergic to non-steroidal anti-inflammatory drugs usually tolerate paracetamol and use corticosteroids and selective COX-2 inhibitors. There are also drug desensitizations, although they are usually done in extreme cases.