It can be confusing when you see the terms adverse reactions and side effects. Do they mean the same thing? Sometimes, but not always. Adverse Drug Reactions and Clinical Pharmacology - Learn about from the Merck Manuals - Medical Professional Version. An adverse drug reaction (ADR) is an injury caused by taking medication. ADRs may occur following a single dose or prolonged administration of a drug or.
Although the exact number of ADRs is not certain, ADRs represent a significant public health problem that is, for the most part, preventable 1. Incidence and severity of adverse drug reactions vary by patient characteristics eg, age, sex, ethnicity, coexisting disorders, genetic or geographic factors and by drug factors eg, type of drug, administration route, treatment duration, dosage, bioavailability. Incidence is higher with advanced age and polypharmacy. The contribution of prescribing and adherence errors to the incidence of ADRs is unclear.
Adverse drug events in U. Agency for Healthcare Research and Quality. Most adverse drug reactions are dose-related; others are allergic or idiosyncratic. Dose-related ADRs are particularly a concern when drugs have a narrow therapeutic index eg, hemorrhage with oral anticoagulants.
ADRs may result from decreased drug clearance in patients with impaired renal or hepatic function or from drug-drug interactions. Allergic ADRs are not dose-related and require prior exposure.
Allergies develop when a drug acts as an antigen or allergen. After a patient is sensitized, subsequent exposure to the drug produces one of several different types of allergic reaction. Clinical history and appropriate skin tests can sometimes help predict allergic ADRs.
They occur in a small percentage of patients given a drug. Idiosyncrasy is an imprecise term that has been defined as a genetically determined abnormal response to a drug, but not all idiosyncratic reactions have a pharmacogenetic cause.
The term may become obsolete as specific mechanisms of ADRs become known. 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. Information on reporting these can be found at: The BNF includes clinically relevant side-effects for most drugs; an exhaustive list is not included for drugs that are used by specialists e. Recognising that hypersensitivity reactions including anaphylactic and anaphylactoid reactions can occur with virtually all drugs, this effect is not generally listed, unless the drug carries an increased risk of such reactions or specific management advice is provided by the manufacturer.
Administration site reactions have been omitted from the BNF e. The BNF also omits effects that are likely to have little clinical consequence e.
Drugs that are applied locally or topically carry a theoretical or low risk of systemic absorption and therefore systemic side-effects for these drugs are not listed in the BNF unless they are associated with a high risk to patient safety. Infections are a known complication of treatment with drugs that affect the immune system e. Side-effects are generally listed alphabetically in order of frequency. In the product literature the frequency of side-effects is generally described as follows:.
For consistency, the terms used to describe side-effects are standardised using a defined vocabulary across all of the drug monographs in the BNF e. When an infant is born with a congenital abnormality or there is a malformed aborted fetus doctors are asked to consider whether this might be an adverse reaction to a drug and to report all drugs including self-medication taken during pregnancy.
Particular vigilance is required to identify and report adverse reactions in children, including those resulting from the unlicensed use of medicines; all suspected reactions should be reported directly to the MHRA through the Yellow Card Scheme see also Adverse Drug Reactions in Children. Suspected drug allergy is any reaction caused by a drug with clinical features compatible with an immunological mechanism. All drugs have the potential to cause adverse drug reactions, but not all of these are allergic in nature.
A reaction is more likely to be caused by drug allergy if:. A suspected reaction is less likely to be caused by a drug allergy if there is a possible non-drug cause or if there are only gastro-intestinal symptoms present. The following signs, allergic patterns and timing of onset can be used to help decide whether to suspect drug allergy:.
Immediate, rapidly-evolving reactions onset usually less than 1 hour after drug exposure. Non-immediate reactions, without systemic involvement onset usually 6—10 days after first drug exposure or 3 days after second exposure. Non-immediate reactions, with systemic involvement onset may be variable, usually 3 days to 6 weeks after first drug exposure, depending on features, or 3 days after second exposure.
Suspected drug allergy information should be clearly and accurately documented in clinical notes and prescriptions, and shared among all healthcare professionals. Patients should be given information about which drugs and drug-classes to avoid and encouraged to share their drug allergy status. If a drug allergy is suspected, consider stopping the suspected drug and advising the patient or carer to avoid this drug in future. Symptoms of the acute reaction should be treated, in hospital if severe.
Patients presenting with a suspected anaphylactic reaction, or a severe or non-immediate cutaneous reaction, should be referred to a specialist drug allergy service. Patients presenting with a suspected drug allergic reaction or anaphylaxis to NSAIDs, and local and general anaesthetics may also need to be referred to a specialist drug allergy service, e. Patients presenting with a suspected drug allergic reaction or anaphylaxis associated with beta-lactam antibiotics should be referred to a specialist drug allergy service if their disease or condition can only be treated by a beta-lactam antibiotic or they are likely to need beta-lactam antibiotics frequently in the future e.
For further information see Drug allergy: Drug-induced disorders of the mouth may be due to a local action on the mouth or to a systemic effect manifested by oral changes. Medicaments left in contact with or applied directly to the oral mucosa can lead to inflammation or ulceration; the possibility of allergy should also be borne in mind.
Aspirin tablets allowed to dissolve in the sulcus for the treatment of toothache can lead to a white patch followed by ulceration. Flavouring agents, particularly essential oils , may sensitise the skin, but mucosal swelling is not usually prominent. The oral mucosa is particularly vulnerable to ulceration in patients treated with cytotoxic drugs, e.
Other drugs capable of causing oral ulceration include ACE inhibitors, gold, nicorandil , NSAIDs, pancreatin , penicillamine , proguanil hydrochloride , and protease inhibitors. Erythema multiforme or Stevens-Johnson syndrome may follow the use of a wide range of drugs including antibacterials, antiretrovirals, sulfonamide derivatives, and anticonvulsants ; the oral mucosa may be extensively ulcerated, with characteristic target lesions on the skin.
Oral lesions of toxic epidermal necrolysis have been reported with a similar range of drugs. Candidiasis can complicate treatment with antibacterials and immunosuppressants and is an occasional side-effect of corticosteroid inhalers.
Brown staining of the teeth frequently follows the use of chlorhexidine mouthwash, spray or gel, but can readily be removed by polishing. Iron salts in liquid form can stain the enamel black. Superficial staining has been reported rarely with co-amoxiclav suspension.
Intrinsic staining of the teeth is most commonly caused by tetracyclines. They will affect the teeth if given at any time from about the fourth month in utero until the age of twelve years; they are contra-indicated during pregnancy, in breast-feeding women, and in children under 12 years.
All tetracyclines can cause permanent, unsightly staining in children, the colour varying from yellow to grey.
From Wikipedia, the free encyclopedia. Adverse drug reaction A red skin rash due to a drug reaction An adverse drug reaction ADR is an injury caused by taking medication. Retrieved 12 July A Textbook of Clinical Pharmacology and Therapeutics.
Pathogenesis of adverse drug reactions. Textbook of adverse drug reactions. Oxford University Press, Davidson's principles and practice of medicine 19th ed. Archived from the original on 29 September Archived from the original on Archived from the original on 30 August The Annals of Pharmacotherapy.
Archived from the original on 7 September Retrieved 18 September Archived from the original on 1 July Retrieved 2 June British journal of hospital medicine London, England: Ryoikibetsu shokogun shirizu Agency for Healthcare Research and Quality. British Journal of General Practice. Iatrogenesis Medical malpractice Medical error Patient safety Medical debt Unnecessary health care Adverse effect medicine Patient abuse.
Adverse drug reaction Hospital-acquired pneumonia Hospital-acquired infection Hand washing. Consequences of external causes T66—T78 , — Hypothermia Immersion foot syndromes Trench foot Tropical immersion foot Warm water immersion foot Chilblains Frostbite Aerosol burn Cold intolerance Acrocyanosis Erythrocyanosis crurum.
Radiation poisoning Radiation burn Chronic radiation keratosis Eosinophilic, polymorphic, and pruritic eruption associated with radiotherapy Radiation acne Radiation-induced cancer Radiation recall reaction Radiation-induced erythema multiforme Radiation-induced hypertrophic scar Radiation-induced keloid Radiation-induced morphea. Physical abuse Sexual abuse Psychological abuse. Motion sickness Seasickness Airsickness Space adaptation syndrome. Electric shock Drowning Lightning injuries.
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An adverse reaction to a drug has been defined as any noxious or unintended reaction to a drug that is administered in standard doses by the. Adverse reactions to medicines include side effects, reactions between two or more medicines or herbal supplements, reactions between a food and a medicine. 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.