Abstract

The circumstances of matching the concepts of risk factor and disease, increase in medicalization with more drugs treatments, the effect of creating a growing set of multimorbidity and polypharmacy, and the changes in the perceived severity of the disease, produce a dramatic increase of the adverse drug reactions (ADRs) and the drug-drug interactions (IDDs), as an intermediate consequence of the previous reasons. This situation is changing disease symptoms because of ADRs and DDIs, and it can have important consequences, and can give rise to, among others, the following effects:

1. There are more symptoms of ADRs initially classified as very rare or not described.
2. They are “disorganized” symptoms where no way to achieve an overall diagnosis that order to the whole.
3. There are symptoms in a lighter degree in some diseases, so that they can go unnoticed with the consequent risk.
4. There are confusing between symptoms of a new disease or an ADR, which makes it difficult to achieve a diagnosis.
5. The appearance of a second disease as a result of the treatment of the first, or increased aggressiveness of one disease.
6. The appearance of drug-induced systemic processes.
7. The appearance of yatrogenic infections; and,
8. Drug interference with laboratory tests. Due to changing the symptoms that were previously considered as indicators of certain diseases, especially in general medicine, where there were already some circumstances that make the diagnosis more complex, will be increasingly difficult to understand, detect, diagnose, prevent, and treat diseases reasonably and within a biopsychosocial framework.

Keywords:General practitioner; Drug-related side effects and adverse reactions; Drug interactions; Disease; Diagnosis; Medications; Multimorbidity; Polypharmacy; Symptom; Medically unexplained symptoms; Symptom assessment