Definition of Adverse reaction
Adverse reaction: In pharmacology, any unexpected or dangerous reaction to a drug. An unwanted effect caused by the administration of a drug. The onset of the adverse reaction may be sudden or develop over time.
Also called an adverse drug event (ADE), adverse drug reaction (ADR), adverse effect or adverse event.
Source: MedTerms™ Medical Dictionaryhttp://www.medterms.com/script/main/art.asp?articlekey=26227
Last Editorial Review: 8/14/2004
Medical Dictionary Definitions A - Z
Search Medical Dictionary
Women's Health
Find out what women really need.
From WebMD
Women's Health Resources
- Photos: Cold Sore or Canker Sore?
- How Healthy Is Your Skin? Start Here
- Preparing for a Healthy Pregnancy
Featured Centers
- Top 10 Asthma Cities
- Health Check: How to Choose The Right Vitamins
- 10 Triggers for the Holiday Blues
Health Solutions From Our Sponsors
Most Popular Topics
Explore 80+ Centers
- Allergy
- Allergy Medications
- Anaphylaxis
- Antidepressants
- Anxiety
- Arthritis
- Asthma
- Baby's Health
- Back, Neck, Head Injury
- Bioterrorism, Warfare
- Blood, Lymphatic System
- Bone, Joint, Muscle
- Brain, Nervous System
- Breathing Difficulties
- Burns
- Camping
- Cancer, Tumors
- Children's Health
- Cholesterol
- Cold and Flu
- CPR, Choking
- Cuts, Scrapes, Bruises
- Dementia
- Depression
- Diabetes
- Diabetic Coma, Insulin Shock
- Digestive System
- Dislocations
- Drowning
- Drug Overdose
- Ear, Nose, Throat
- Emotional Wellness
- Endocrine System
- Environmental Injuries
- Erectile Dysfunction
- Exercise, Nutrition
- Eye, Vision
- Fainting
- Fever
- First Aid, Emergency
- First Aid Kits
- Food Poisoning
- Foreign Bodies
- Fractures, Broken Bones
- Glaucoma
- Headache
- Health, Medical
- Heartburn, GERD, Reflux
- Heart, Blood Vessels
- Heart Attack
- Hepatitis
- Immune System
- Incontinence
- Infections
- Kidneys, Urinary System
- Lung, Airway
- Medications
- Men's Health
- Mental Health, Behavior
- Multiple Sclerosis
- Nosebleeds
- Osteoporosis
- Outdoor Living
- Overexposure
- Poisoning
- Procedures
- Psoriasis
- Public Health
- Scuba Diving, Swimming
- Seizures
- Senior Health
- Shock
- Skin, Hair, Nails
- Sleep Disorders
- Social, Family Health
- Sports Injury
- Sprains, Strains
- Statins
- STDs
- Substance Abuse
- Teen Health
- Teeth, Mouth, Oral Health
- Weight Management
- Wilderness Emergencies
- Women's Health
- Wounds
