Adverse reaction reports are communications submitted by healthcare professionals, patients, or other healthcare-related parties to report the occurrence of an unwanted effect associated with the use of a medication, medical device, or treatment. These reports are part of pharmacovigilance systems, whose objective is to collect, analyze, and evaluate information on the safety of medicines once they are available to the public.

Although medicines undergo rigorous clinical trials before being marketed, some adverse effects are only detected when they are used in real-world conditions and in a much larger number of patients. For this reason, spontaneous reporting remains an essential tool for ensuring their safe use.

For pharmacists, reporting suspected adverse reactions is an important part of their patient care duties. Thanks to their accessibility and close relationship with patients, as well as their ongoing monitoring of treatments, they are in a unique position to detect potential medication-related problems, even before the patient consults other healthcare professionals.

Which Reactions Should Be Reported?

One of the most common questions is which cases should be reported. The recommendation is clear: If a reaction is suspected, it is best to report it. It is not necessary to prove that a medication caused the reaction; assessing the causal relationship is the responsibility of the pharmacovigilance centers.

It is recommended to pay special attention to serious adverse reactions that result in hospitalization, life-threatening conditions, disability, congenital anomalies, or death; unexpected reactions or those not described in the prescribing information; suspected reactions related to medications subject to additional monitoring, identified by the black triangle symbol (▼); reactions associated with vaccines and biologics; cases in the pediatric population; and suspected cases related to medication errors, overdose, abuse, misuse, or use outside authorized conditions.

What Information Must the Report Include?

In Spain, reports can be submitted electronically via the online form of the Spanish Pharmacovigilance System or using the yellow card from the corresponding Regional Pharmacovigilance Center.

For a report to be properly evaluated, it must include at least four essential elements. First, the suspected medication. Whenever possible, the full brand name, strength, dosage form, and packaging should be provided. For biologic medications, it is also recommended to include the lot number.

Second, the adverse reaction should be described in detail. This should include the diagnosis or symptoms observed, the date of onset, severity, any treatment given, and the patient’s outcome.

Third, patient information. It is essential to provide the basic information needed to identify the case, such as sex, age, weight, and a clinical identifier (medical record number or health insurance card number), while always maintaining confidentiality.

Fourth, reporter information must be included, along with the reporter’s name and either an email address or phone number, so the Pharmacovigilance Center can follow up if additional details are needed.

When possible, additional information is also helpful, including other medications the patient is taking — such as self-medications or herbal products — relevant medical history, allergies, treatment start and stop dates, and whether the reaction improved after the drug was discontinued.

How to Identify a Possible Adverse Reaction?

In many cases, it will be the patient themselves who reports the symptoms that have appeared after starting treatment. However, some reactions may go unnoticed or be mistaken for the underlying condition itself.

Pharmacists should remain alert to the appearance of new symptoms after starting a medication, changes that coincide with an increase or decrease in the dosage, reactions that disappear upon discontinuation of treatment, or possible interactions with other medications or over-the-counter products.

What Happens After a Report Is Submitted?

Once submitted, the Regional Pharmacovigilance Center reviews the report and enters it into the Spanish Pharmacovigilance System for Human Use Medicines. It is then analyzed alongside thousands of other national and international reports to detect potential safety signals.

The information obtained may lead to changes in the prescribing information and package insert, new recommendations for use, the issuance of safety alerts, or, in exceptional cases, the suspension or withdrawal of the medication. Therefore, every report — even when there is uncertainty about the causal relationship — can be crucial for improving our understanding of medication safety and protecting patients’ health.

This story was translated from El Médico Interactivo on Univadis, part of the Medscape Professional Network.