Pharmocology

is the study of drugs and their effects on the living system it is the science behind of what happens to the body and the drug itself.Drugs alter the chemistry within our body by exerting biochemical or physiological effect in cells,tissues organs and organism

Plants,minerals,Hormones ,man made chemicals and genetically engineered substances

Provides a framework for the licensing of medicines and clarifies the classes and schedules of medicinal products available in the UK.

This prevents the misuse of controlled drugs by imposing a ban on possession, supply, manufacture of controlled drugs Drugs are divided into classes – A, B and C based on their relative harm

This intends to restrict the production, sale and supply of psychoactive substances often referred to as “legal highs”

Intravenous/intraosseous Inhaled/nebulised Sublingual Buccal Intramuscular Rectal Sub-cutaneous Oral

Enternal drugs - taken through GI tract i.e rectum and oral Parental - injected into the body Inhaled - respiratory system Topical - applied to skin or mucous membrane

Pharmacodynamics Pharmocokinetics

What the drug does to the body the mechanism of drug actions and adverse effects at biochemical level,studys the dose and response

Drugs bind to a specific receptors this then alters the cell physiology and produces an effect.This drug mimics the endogenous effect. An agonist - drug binds to receptors creates a response An antagonist - Binds to receptors blocks a response

Increase the activity of specific organs or systems adrenaline for example increase heart rate.

decrease activity specific organs or systems alcohol for example depresses the cns in the brain

Topical creams increase local circulation in deeper structures to act as pain relief or they can block impulses in the nervous system (local anaesthetics)

When the body has a deficiency of an endogenous substance it is replaced. Such as insulin for diabetes mellitus

Some selective drugs are toxic for the infecting organism or certain cells – antibiotics or anticancer drugs

how drugs enter the body,reach their site of action and are eliminated

Liberation Absorption Distribution Metabolism Excretion

only applies to oral medication is the process by which the drug is released during digestion from the tablet or capsule All drugs when released from the ‘delivery device’ are transported to the liver so the active ingredient (i.e. the drug) can be metabolized

This is the process of how a drug moves from the site of administration to systemic circulation Oral is the slowest which needs to be activated by the lover before it reaches systemic circulation Aspirin is an acidic tablet so is better absorbed via the stomach which is an acidic environment. Rectal diazepam is alkaline so is better absorbed via intestines

Lipid water solubility Areas of absorbing surface concentration of the drug

Drugs that are lipid soluble are better absorbed than water soluble… this is due to the hydrophilic heads found in the phospholipid bilayer of cells which naturally absorb water

The inner layer of the small intestines are covered in villi – expanding this means the surface area is perfect for absorption to occur. Other areas of the body don’t have this type of surface area

If a drug is more concentrated, it will be harder for the drug to enter through the membranes of the blood vessel walls

The smaller the particle size, faster the absorption. Important to be aware of some drugs whose particles are so small they can cross certain barriers in the body such as the blood brain barrier or the barrier of the placenta