View
213
Download
0
Tags:
Embed Size (px)
Citation preview
Drug Hypersensitivity Prevalence in the Adult
Population
Group 13
Medical Faculty of University of PortoMedical Faculty of University of Porto
Introduction to MedicineIntroduction to Medicine2005/062005/06
2
Summary
Introduction Aim Methods Expected Results Limitations
3
Introduction
Drug hypersensitivity reactions are the side effects of drugs taken at a dose that is tolerated by normal subjects1
Drug hypersensitivity reactions are thought to represent one-third of adverse drug reactions1
1- Gomes et al. Self-reported drug allergy in a general adult Portuguese population.
4
Introduction
80% of adverse drug reactions are predictable (type A reactions)2
Type B reactions are not predictable, are dose independent, are not related with the pharmacologic actions of the drug and are extremely important because they are often serious and can cause death2,3
Allergic reactions are one of the examples of unpredictable reactions3
2 - Gruchalla, Rebecca. Drug metabolism, danger signals, and drug-induced hypersensitivity.
3 –Gruchalla, Rebecca. Understanding drug allergies.
5
Introduction
Drug hypersensitivity is a common and complicated problem in clinical practice4
It shows in various forms of autoimmune diseases4
Diagnosis of drug hypersensibility is difficult4
Drug-allergic reactions are underdiagnosed4
4– Demoly, P, Kropf, R:, Bircher A. et Pichler W.J. Drug hypersensitivity: questionnaire.
6
Introduction
5% of all hospital admissions are due to adverse drug reactions2
Fatal adverse drug reactions are between the 4th and 6th leading cause of death of hospitalized patients in the USA3
3-7% of the population experience an adverse drug reaction1
1- Gomes et al. Self-reported drug allergy in a general adult Portuguese population.
2 - Gruchalla, Rebecca. Drug metabolism, danger signals, and drug-induced hypersensitivity.
3 - Gruchalla, Rebecca. Understanding drug allergies.
7
Introduction
Drugs most commonly observed as the cause of these reactions3: – ampicillin– amoxicillin– trimethoprim-sulfamethoxazole – penicillin
3 - Gruchalla, Rebecca. Understanding drug allergies.
8
Introduction Common diseases and symptoms provoked
by drug hypersensitivity4:– Exanthema (most common)– Urticaria– Anaphylaxis– Blood cell dyscrasia– Fever– Intersticial lung disease– Hepatitis– Nephritis
4– Demoly, P, Kropf, R:, Bircher A. et Pichler W.J. Drug hypersensitivity: questionnaire.
© Dermatology database of Institute for Biomedical Informatics, Faculty of Medicine, Ljubljana, Slovenia
9
Aim
The aim of this study is to determine the prevalence of drug hypersensitivity in the
adult population of Porto region
10
Secondary Aims Identify the drugs that are more frequently
associated to hypersensitive reactions, classifying them using the INFARMED data base;
Describe the different types of allergic expression; Relate the allergic reactions already described with
the presence of some diseases; Study the possible existence of an association
between drug hypersensitivity in the interviewed subject and the number of relatives with the same pathology.
11
Study participants Target population - all adult people (above 18
years old) living in Porto region Available population - all adult people (above 18
years old) living in Porto region with telephone in their household
Unit of Analysis – single person Inclusion Criteria – be an adult (above 18 years
old), have phone in their household, live in Porto and have capacities to answer the questionnaire properly
Exclusion Criteria – see fluxogram
12
Fluxogram
13
Study design
Observational, cross-sectional and descriptive study, realized by phone interviews
Data collection method – Phone interview, filling up a questionnaire previously designed
Sample selection method – random digit dialling
Frequency measurement - prevalence
14
Random Digital Dialling5
Will be aplicated to the telephone numbers of Porto region
Software will randomly select digits of the type 22xxxxxxx, where x is a digit between 0 and 9
5- Groves, R et al. Telephone Survey Methodology.
15
Data collection methods
Telephone interview Questionnaire
16
Main variables description
Age Sex Reaction type Symptoms Suspected drug Allergies in family medical history
17
Statistical Analysis
We will use SPSS® 13.0 software Descriptive statistics and hypothesis t tests
shall be used to analyse data We will use odds ratio as an association
measure
18
Gantt chart
Microsoft Project
19
Expected Results
We expect that our study reveals about 3-7% of adverse drug reactions in our population as reported1
1- Gomes et al. Self-reported drug allergy in a general adult Portuguese population.
20
Main limitations
Telephone interviews are not accurate to determine whether a reaction is really of hypersensitivity or not
People living in Porto, without telephone at home are excluded
Interviews will be done in a restricted period of time
Low response rate
21
References1 - Gomes et al. Self-reported drug allergy in a general adult
Portuguese population. Clin Exp Allergy 2004; 34:1597-1601
2 - Gruchalla, Rebecca. Drug metabolism, danger signals, and drug-induced hypersensitivity. J Allergy Clin Immunol October 2001
3 - Gruchalla, Rebecca. Understanding drug allergies. J Allergy Clin Immunol June 2000
4 - Demoly, P, Kropf, R:, Bircher A. et Pichler W.J. Drug hypersensitivity: questionnaire. Allergy 1999, 54, 999-1003
5 - Groves, R et al. Telephone Survey Methodology. John Wiley & Sons Inc 2001
The End