Adverse drug effect

Adverse drug effect (ADE) refers to the unintended, harmful reactions or side effects that occur with the use of medication. These effects can occur with any type of medication, including prescription drugs, over-the-counter drugs, herbal medicine, and supplements. ADEs can range from minor to severe and can occur immediately or develop over time.

Definition

An adverse drug effect is defined as an unwanted or harmful reaction experienced following the administration of a drug or combination of drugs under normal conditions of use and is suspected to be related to the drug. The term is often used interchangeably with adverse drug reaction (ADR), although some definitions distinguish between the two.

Classification

Adverse drug effects can be classified in several ways, such as by severity, predictability, and whether the effect is due to the drug's primary or secondary actions. The World Health Organization (WHO) classifies ADEs into two main types: Type A (augmented) and Type B (bizarre).

Type A

Type A reactions are the most common type of ADE and are usually predictable based on the known pharmacology of the drug. They are often dose-dependent and can be avoided or reduced by adjusting the dosage or method of administration.

Type B

Type B reactions are less common and are not predictable based on the known pharmacology of the drug. They are not dose-dependent and are often due to individual patient factors such as genetic variations or immune responses.

Causes

Adverse drug effects can be caused by a variety of factors, including the drug's mechanism of action, the dose, the method of administration, the duration of use, and individual patient factors such as age, sex, genetics, and overall health status. Interactions between drugs can also cause ADEs, as can errors in prescribing, dispensing, or administering drugs.

Prevention and Management

Preventing and managing adverse drug effects involves a combination of strategies, including careful drug selection, appropriate dosing, monitoring for known side effects, patient education, and prompt recognition and management of ADEs when they occur. In some cases, an ADE may require discontinuation of the drug, dose reduction, or substitution with a different drug.

See also

• Pharmacovigilance
• Drug interaction
• Medication error
• Drug-induced diseases