An adverse drug reaction (ADR), also known as a side effect, is an undesirable or harmful reaction that occurs as a result of using a medication or drug.
These reactions can range from mild to severe and can occur immediately after taking the drug or after prolonged use.
ADRs can affect various systems in the body, including the gastrointestinal system, cardiovascular system, nervous system, skin, and others.
While research indicates that between 5% and 10% of patients may experience an ADR at admission, during hospitalization, or at discharge, despite numerous prevention measures, the incidence of ADRs has remained largely stable over time.
The approach employed to identify such events is invariably correlated with the event frequency, and the majority of ADRs do not result in significant systemic signs.
Nevertheless, given the related morbidity and mortality, the potential financial burden, and the potential impact on the prescriber-patient relationship, it is important to carefully examine the frequency of potential damage.
Antiplatelet, anticoagulant, cytotoxic, immunosuppressant, diuretic, antidiabetic, and antibiotic medications have all been specifically linked to ADR-related hospital admissions.
When fatal ADRs do occur, hemorrhage is frequently to blame, with an antithrombotic/anticoagulant co-administered with a non-steroidal anti-inflammatory drug (NSAID) being the most frequently suspected cause.
There are several types of adverse drug reactions:
Type A (Augmented): These are the most common ADRs and occur predictably based on the known pharmacological actions of the drug.
For example, if a medication has a known side effect of drowsiness, experiencing drowsiness after taking the drug would be a Type A ADR.
Type B (Bizarre): These reactions are idiosyncratic and not predictable based on the known pharmacological actions of the drug.
They are often caused by individual variations in drug metabolism or immune responses.
Type B ADRs are usually rare but can be severe. An example would be an allergic reaction to a medication.
Type C (Chronic): These reactions occur with long-term drug use and are often related to cumulative drug effects.
Examples include drug-induced osteoporosis or drug-induced diabetes.
Type D (Delayed): These reactions have a delayed onset, sometimes occurring weeks or months after starting a medication.
An example is drug-induced liver damage.
Type E (End-of-treatment): These reactions occur when a drug is discontinued and can include withdrawal symptoms or rebound effects.
For instance, abrupt discontinuation of certain antidepressant medications can lead to withdrawal symptoms like dizziness and nausea.
Type F (Failure): These reactions occur when a drug fails to achieve its intended therapeutic effect or has diminished effectiveness over time.
Although frequently cited, this fundamental classification does not apply to all ADRs, such as those with withdrawal reactions (such as rebound hypertension with the cessation of centrally acting antihypertensives) or long-term adverse effects associated with drug exposure (such as osteoporosis with long-term corticosteroid treatment).
The Dose, Time, and Susceptibility – “DoTS” classification system, which classifies reactions based on the drug dose, the time course of the reaction, and any pertinent susceptibility variables (such as genetic, pathological, and other biological characteristics), is an alternative and perhaps more thorough system.
DoTS have the advantage of being beneficial to take into account the diagnosis and prevention of ADRs in practice in addition to classifying reactions.
Prevention of adverse drug reactions
While certain adverse drug reactions (ADRs) are unanticipated, such anaphylaxis in a patient after a single uneventful exposure to an antibiotic containing penicillin, many may be avoided with enough planning and monitoring.
When a drug treatment plan is preventable (or avoidable), it usually means that it does not follow the most recent evidence-based guidelines or is overly optimistic given the current situation.
Epidemiological studies frequently discover that between one-third and fifty percent of ADRs are (at least possibly) avoidable, even though avoidability is considerably simpler to identify after the fact.
However, one of the most effective ways to lower the risk of patient damage is by actions that lower the likelihood that an ADR will occur.
There are two fundamental actions that can be taken to avoid an ADR:
Determine the subset of patients who are most likely to experience the negative effect and adjust your treatment plan accordingly.
Make sure the treatment strategy minimizes any potential negative effects.
Diagnosing adverse drug reactions
Diagnosing an adverse drug reaction involves assessing the signs, symptoms, and medical history of a patient to determine if they are experiencing an adverse reaction to a particular medication.
Here are the general steps involved in diagnosing an adverse drug reaction:
Identify the symptoms:
The first step is to recognize the presence of symptoms that may be associated with an adverse drug reaction.
These symptoms can vary widely depending on the medication and individual patient characteristics.
Common symptoms include skin rashes, itching, swelling, difficulty breathing, gastrointestinal disturbances, dizziness, and changes in mental state.
Review medical history: The healthcare provider will review the patient’s medical history, including previous drug exposures and any known drug allergies or sensitivities. It is important to consider other potential causes of the symptoms and rule out alternative explanations.
Conduct a physical examination: A thorough physical examination may be performed to assess the patient’s overall health and look for any specific signs or indications of an adverse drug reaction.
For example, the presence of a rash or jaundice may suggest a drug-related reaction.
Obtain additional information: The healthcare provider may ask the patient about their medication regimen, including the timing and dosage of the drug in question.
It can be helpful to gather information about any recent changes in medication or the initiation of new drugs that could be contributing to the symptoms.
Consult drug information resources: The healthcare provider may refer to drug information resources, such as package inserts, drug databases, or medical literature, to identify known adverse reactions associated with the specific medication in question.
These resources provide valuable information about the drug’s side effects, contraindications, and warnings.
Order diagnostic tests: Depending on the suspected adverse drug reaction and the patient’s symptoms, additional diagnostic tests may be ordered. These tests can help confirm or rule out other potential causes and assess the extent of organ involvement.
For example, blood tests, imaging studies, or specialized tests may be performed to evaluate liver function, kidney function, or allergic responses.
Monitor response to medication withdrawal: In some cases, the healthcare provider may choose to discontinue the suspected medication to observe whether the symptoms improve or resolve.
If the symptoms subside after medication withdrawal and reappear upon re-exposure, it provides supporting evidence for an adverse drug reaction.
Consultation with specialists: Depending on the complexity or severity of the adverse drug reaction, the healthcare provider may consult with specialists, such as allergists, dermatologists, or pharmacologists, who have expertise in diagnosing and managing drug reactions.
It is important to note that diagnosing an adverse drug reaction can be challenging, as symptoms can be nonspecific or resemble other medical conditions.
Therefore, a comprehensive evaluation by a qualified healthcare professional is crucial to arrive at an accurate diagnosis and ensure appropriate management.
Pharmacovigilance is the science and activities related to the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems associated with the use of pharmaceutical products. It plays a crucial role in monitoring the safety of medications once they are approved and made available to the general population.
The main objectives of Pharmacovigilance are:
Detection of adverse drug reactions (ADRs):
Pharmacovigilance aims to identify and collect information on any unexpected or harmful reactions to medications.
This includes monitoring known adverse effects, as well as discovering new or rare reactions that may arise during real-world use.
Assessment and evaluation: Once an adverse event is reported, pharmacovigilance experts evaluate the data to determine the severity, frequency, and causality of the event.
This involves analyzing the available evidence, conducting risk-benefit assessments, and determining if any regulatory action is required.
Risk management and minimization:
Pharmacovigilance activities also focus on developing strategies to minimize risks associated with medication use.
This may involve updating product information, implementing risk mitigation measures, or even issuing warnings, contraindications, or restrictions on drug usage.
Communication and information dissemination:
Timely and accurate communication of drug safety information is essential to healthcare professionals, patients, and regulatory authorities.
Pharmacovigilance ensures that relevant information regarding the safety of medications is shared appropriately, allowing for informed decision-making.
Signal detection and analysis: Pharmacovigilance employs various methods and databases to identify potential safety concerns or signals. By analyzing data from spontaneous reporting systems, clinical trials, observational studies, and other sources, pharmacovigilance experts can detect patterns and signals that may indicate previously unrecognized risks.
Post-marketing surveillance: Pharmacovigilance is primarily concerned with monitoring drugs once they are on the market, complementing the pre-approval clinical trials. This enables the continuous assessment of medication safety and effectiveness in real-world settings, as well as the identification of potential risks that may not have been evident during pre-market evaluations.
It’s important to report any suspected adverse drug reactions to your healthcare provider. They can help assess the severity of the reaction, adjust your medication if needed, or suggest alternative treatment options.
Pharmacovigilance programs also play a crucial role in monitoring and collecting data on adverse drug reactions to ensure patient safety.
The author is a science student.
Disclaimer: Ideas, opinions and views in the article are write’s own and may not be in accord with those of Kashmir Despatch