clinical pharmacology
Adverse Drug Reactions
Symptoms and Signs of Adverse Drug Reactions
Adverse drug reactions are usually classified as mild, moderate, severe, or lethal (see table Classification of Adverse Drug Reactions (ADRs) ). Severe or lethal ADRs may be specifically mentioned in black box warnings in the physician prescribing information provided by the manufacturer. Symptoms and signs may manifest soon after the first dose or only after chronic use. They may obviously result from drug or medication use or be too subtle to identify as related to that drug or medication. In older adults, subtle ADRs can cause functional deterioration, changes in mental status, failure to thrive, loss of appetite, confusion, and depression. Allergic ADRs typically occur soon after a drug is taken but generally do not occur after the first dose; typically, they occur when the drug is given after an initial exposure. Symptoms can include itching, rash, fixed-drug eruption, upper or lower airway edema with difficulty breathing, and/or hypotension. Idiosyncratic ADRs can produce almost any symptom or sign and usually cannot be predicted. 