Pharmacology of Sympathomimetics and Analgesics

Sympathomimetics

• Similar chemical structure to amphetamines (stimulants)
• Enhance the release of endogenous noradrenaline (α and β agonists)
• Increase heart rate and blood pressure, elevate mood, decrease appetite
• Used as nasal decongestants due to vasoconstriction of nasal blood vessels
• International Olympic Committee banned ephedrine products
• Large packs of pseudoephedrine/ephedrine replaced by smaller packs (720mg equivalent of 12/60mg tablets or 24/30mg tablets)
• One pack per customer and sales should be handled by a pharmacist.

Analgesics

• Highest volume of OTC sales
• Common abuse: chronic headaches, medication overuse
• Most problematic products contain opioids (e.g., codeine, especially those on opioid substitution therapy (OST))
• Some contain caffeine or antihistamines (can cause withdrawal or tolerance problems)
• Analgesics, such as ibuprofen and aspirin, have subtle reinforcing effects at high doses
• Paracetamol (acetaminophen) is toxic
• All packs now contain warnings about 3-day maximum use and highlighting the potential for dependency.

Opioids

• Primarily codeine, dihydrocodeine, and loperamide
• Act as agonists at mu receptors (analgesia, bradycardia, cough suppression, euphoria, miosis, dependence, reduced GI motility, respiratory depression, sedation)
• Synergistic effect with GABA agonists (e.g., alcohol, benzodiazepines, Z-drugs)
• Therapeutic effect via active metabolites (e.g., codeine to morphine, hydrocodone, hydromorphone, and morphine-6-glucuronide).
• Dependent on CYP2D6, 3A4 enzymes (genetic polymorphism dependent) and function of the P-glycoprotein pump.
• Loperamide is an antidiarrheal drug, with less CNS effect at the therapeutic dose; a higher dose may be required to achieve the antidiarrheal effect

Antihistamines

• Sedating antihistamines (in large doses) can produce mild euphoria or a dissociative effect due to anti-muscarinic properties
• Diphenhydramine is used as a cough suppressant and sleep aid
• Chlorphenamine is used for rashes and itching
• Cyclizine is used against travel sickness
• Promethazine is used against travel sickness
• Elderly people are particularly susceptible to side effects
• Antihistamines can substitute or enhance the effects of illicit drugs

Antitussives

• Cough stimulus is from irritation of respiratory mucosa, due to contamination/infection
• Dextromethorphan (DM) used to suppress (dry irritating) cough and inhibit the medullary cough centre
• DMD is a direct acting metabolite that can induce a dissociative state. (Similar to PCP) main effects: dissociative, euphoria, hallucinations
• Tolerance and dependence(tachycardia, hypertension, psychosis, mania) common
• Usual doses 300mg per day and maximum doses can reach 2880mg over a few years

Laxatives

• Stimulant laxatives are commonly used by people with eating disorders (e.g., anorexia nervosa, bulimia)
• Designed to alter body image shape
• Laxative abuse can cause diarrhoea, dehydration, hypotension, tachycardia, and hypokalaemia
• Products such as Ex Lax, Dulcolax, and Senokot (sennoside) can be in choc or tablet forms

Treatment

• NHS focuses on other dependencies (alcohol, opioids) - lacking understanding, resources, and services.
• "Cold turkey" (sudden stop) or reducing doses for addiction is a common approach.
• External support (online forums, Narcotics Anonymous), OverCount & Codeine Free are widely used.
• Websites play a supporting role, providing reassurance and connecting people with shared experiences.
• Charities offer additional support.

Atherosclerosis

• Atherosclerosis is typically asymptomatic.
• Usually detected after a heart attack or stroke
• Low density lipoproteins (LDL) levels are commonly used as a predictor for Atherosclerosis
• Blood pressure measurements are also a good indicator.
• Atherosclerosis is the buildup of plaque in the arteries that can block blood flow, leading to heart attacks and strokes
• The formation of plaques begins with age regardless of the person affected.

Risk Factors of Cardiovascular Disease

• Genetic variations/family history
• Lipid disorders
• Hypertension
• Type 2 diabetes
• Smoking, physical inactivity
• Increased cardiovascular risk
• High CRP
• Prior CVD events
• Age, race, sex
• Metabolic syndrome

Detection

• Atherosclerosis detection is typically asymptomatic.
• Manifests after heart attack or stroke
• LDL measures within blood are strong indicators.
• Blood pressure measures are significant indicators.
• 20% of events occur in those without major risk factors
• LDL (Bad cholesterol) form plaques with age.
• Cholesterol is a surrogate marker for CVD.

Prevalence of Risk Factors (Coronary Heart Disease)

• Data is presented in a bar graph format, showing prevalence of risk factors amongst male and female groups
• Data is presented in a bar graph format, showing prevalence of risk factors for men and women.

Relative Risks of Future MI Among Healthy Middle-Aged Men

• Chart displays relative risks of future myocardial infarction (MI) among healthy middle-aged men - factors tested.

Cardiovascular Conditions in Scotland by Age & Deprivation

• Data is presented in graphs showing the percentage of adults with cardiovascular conditions
• Different age groups and levels of deprivation show variations.

Role of the Pharmacist in Health Promotion

• Pharmacists assess, manage, and educate on diseases like high blood pressure, asthma, and diabetes.
• Understanding illness and medications
• Ensuring compliance via community relations with nurses and dentists
• Essential that structures for access are in place so that the public can use those services

Health Disease Progression

• Health progression in a person can range from a healthy individual to someone with a disability/death
• Pre-disease is reversible however once the symptoms become more advanced , it becomes not reversible
• Primary Prevention: Healthy people, preventing diseases from occurring
• Secondary Prevention: Detecting diseases at early stages before they advance
• Tertiary Prevention: Helping people with disabilities and advanced stages of disease.

Ottawa Charter (WHO 1986)

• Encourages empowering people to manage their health.
• Processes for enabling individuals increase their control and improve health.

Health Promotion Strategies and Key Themes

• Health promotion approaches for empowerment, mediation and advocacy.
• Healthy policy building, supportive environments, community action, health skill development, and health services re-evaluation

Definitions of Health

• Health as the absence of disease (ancient Greeks).
• Health as ‘well-being’ (WHO 1948, a complete state of physical, mental, social well-being; not merely the absence of illness)
• Health as a resource (Ottawa charter; a positive concept emphasizing social and individual resources as well as physical capabilities, not merely the absence of disease).

Factors Influencing Health

• Factors influencing human health are multiple and interactive, both within and outside an individual's control.
• Modifiable determinants are individual health behaviours/lifestyles, access to education, employment, and physical environment.
• Non-Modifiable determinants are biology and genetics.

Models for Health and Illness Behaviour

• Models for explaining health and illness behaviours, including the Health Belief Model, Stages of Change Model, Social learning theory etc

Health Belief Model

• For a person to take action, they must believe they are susceptible to a health problem, believe the problem is serious, and believe the advantages of taking action outweigh the disadvantages.

Dahlgren and Whitehead (1991)

• A framework that shows factors influencing health at different levels (individual to societal).
• Demonstrates factors like socioeconomic, cultural, and environmental factors that influence health
• Aims to identify layers and help prevent inequalities in health.

Changing Health Behaviour

• Health behaviour changes based on the individual
• Identify factors posing greatest threat to health.
• Lifestyle factors such as diet, relationships, managing stress, safe sex, drug/alcohol use, exercise and tobacco use.

Factors Influencing Behaviour Change

• Predisposing factors (knowledge, beliefs, attitudes based on life experiences, gender, age)
• Enabling factors (skills, abilities, available resources)
• Reinforcing factors (support from others, encouragement/discouragement)

Percentage of Smokers by Scottish Deprivation Index

• Data visualization showing a trend in smoking prevalence across different levels of deprivation in Scotland.