aetiology and epidemiology

Question 1

what is aetiology

Answer 1

refers to the causes of diseases and pathologies

• can be intrinsic and extrinsic
• if no aetiology can be ascertained the disease is said to be idiopathic

Question 2

intrinsic causes

Answer 2

1) genetic (inherited, acquired)
2) metabolic/hormone disorders
3) cancer
4) allergens and over-reactions

Question 3

example of intrinsic causes

Answer 3

east cancer associated(BRCA) mutations
•BRCA 1 and 2 are tumour suppressor genes.
•Mutations associated with 5-10 % of all female breast cancers.
•Carriers of BRCA mutations are 5 times as likely to develop breast cancer and 10-30 times as likely to develop ovarian cancer.

Question 4

extrinsic causes

Answer 4

infectious: bacteria, viruses, fungi

animal bites and stings

Question 5

aetiology discovery Robert Koch

Answer 5

Robert Koch (1843-1910)- demonstrated that:
•tuberculosis caused by the tubercle bacillus (Mycobacterium tuberculosis)
•anthrax is caused by Bacillus anthracis.
•cholera is caused by Vibrio cholerae.
•in infectious diseases, proof of causation is limited to individual cases that prove experimental evidence

Question 6

what is epidemiology

Answer 6

the study of how often diseases occur in different groups of people and why
-several lines of evidence together are required to infer causation.
•Information used to plan and evaluate strategies to prevent illness and to manage patients in whom disease has already developed.

Question 7

what is syndrome

Answer 7

sometimes several symptoms appear together, either always or more often than what could be expected
.•Yet one of these symptoms is not causing the other

Question 8

what is chain of causation

Answer 8

sometimes no single cause for a disease.
-a chain of causation from an initial trigger to the development of the clinical disease.
•An aetiological agent of disease may require an independent co-factor

Question 9

example of chain of causation

Answer 9

peptic ulcer disease; induced by stress, requires the presence of acid secretion in the stomach and has primary aetiology in Helicobacter pylori infection.

Question 10

aetiological heterogeneity

Answer 10

•Some diseases are defined by their symptoms, but include different conditions with different aetiologies
-heterogeneous conditions example-
diabetes and hepatitis
-conversely, a single aetiology may lead to different diseases- example-. Epstein-Barr virus infection leads to mononucleosis, nasopharyngeal carcinoma or Burkitt’s lymphoma

Question 11

major aetiological diseases

Answer 11

-cardiovascular disease.
•Cancers.
•Neurodegerative diseases (e.g. Alzheimer’s, Parkinson’s) .
•Mental health problems.
•Metabolic diseases (e.g. Diabetes)
•Chronic respiratory diseases (Asthma, COPD)
•Musculoskeletal diseases

Question 12

desired criteria for drugs

Answer 12

• To use a drug that is easy and safe to administer.
• That acts with high specificity—potency at low dose.
• That acts with appropriate duration to give the max advantage and min damage/side effects to the body.
• Low cost availability.

Question 13

types of formulations for drugs

Answer 13

• Tablets.
• Syrups.
• Capsules.
• Inhalers.
• Sprays.
• Aerosols.
• Patches.
• Injections.
• Suppositories.

Question 14

why different formulations

Answer 14

-to provide a product that can be administered.–e.g. inhaler to target drug directly to lungs.
•To remain stable.
•To allow reliable dosing

Question 15

factors affecting individual drug response (physiological)

Answer 15

• factors- age, sex, race/ethnicity, body weight

- effect- Drug efficacy, pharmacokinetics (PK), toxicity

Question 16

factors affecting individual drug response (environmental)

Answer 16

• factors- smoking, alcohol, chemicals, climate, culture, diet
• effect-mostly transient, efficacy, PK, toxicity

Question 17

factors affecting individual drug response (pathological)

Answer 17

• factors- disease state-comorbidities, other treatments

- effect- transient or permanent

Question 18

factors affecting individual drug response (genetic)

Answer 18

• factors- therapeutic targets, metabolising enzymes

- effect- permanent, stable, inherited

Question 19

individual response (example Warfarin)

Answer 19

• Warfarin inhibits vitamin K epoxide reductase (VKOR)
• Prevents blood clotting
• Originally discovered as rodenticide

Question 20

drugs in elderly

Answer 20

1. Drug absorption may be slowed.
2. Changes in the volume of distribution.
3. Hepatic metabolism may be slowed.
4. Typically consume more drugs, chronic diseases, polypharmacy.
5. Age-related changes in receptors and homeostasis control

Question 21

pharmacodynamics changes with ageing

Answer 21

look at picture (screenshot)