Lecture 1 Notes - Introduction to Pharmacology PDF

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Introduction to Pharmacology ...

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Lecture 1 Pharmacology – the science behind drugs, how they are made, their actions, their effects on the body Pharmacy – formulating and dispensing of drugs Therapeutics – the medicinal use of drug to relieve and treat symptoms of a disease Toxicology – the side effects of a drug Drug – the chemical substance of a known substance that produces a biological effect Key mechanisms: -

Binding to the receptors of a neurotransmitter or hormone Binding to enzymes Binding to proteins Binding to carrier proteins or channel proteins

Drugs are exogenous molecules that mimic/block the action of an endogenous molecule by binding to them Agonist drugs – activates a receptor to provoke a response Antagonist drugs – prevents a receptor from being activated Some drugs are reversible and so they are bound to the receptor by weak forces like London forces, but irreversible drugs are bound by covalent bonds Pharmacokinetics – the action the drug has on the body and its physiology Pharmacodynamics - the effects the body has on the drug ie. whether the liver able to efficiently metabolize the drug or distribute it around the body ADME: Adsorption: how quickly the drug can enter the system and be absorbed. It should be lipid soluble, small and chemically stable ie. When going through pH changes. Route of administration. Distribution: where the drug goes once it has been absorbed by the body. Does it go to the target organ? Drugs are usually dissolved in the blood plasma and then transported via the blood so the drug must be water soluble. Also, other factors can affect how effectively the drug is distributed. For example, whether the drug goes into fat stores or binds to other proteins in the blood which prevents it from travelling around. Drugs used to treat brain conditions usually aren’t very effective as they must go past the blood brain barrier. Systemic action – this is where the drug affects the whole body ie. General anesthetic Sometimes drugs need to just work in one area like a local anesthetic, so pharmacokinetics are used to manufacture drugs that are non-systemic Metabolism and excretion: how fast a drug is metabolized and excreted Drugs are metabolized into metabolites in the liver and then excreted in urine, faeces, sweat or breath. People with unhealthy/damages liver will have a hard time metabolizing the drug and so there can be harmful side effects as there is a buildup of metabolites in the liver. Clearance is how effective the body is at clearing out the drug form the blood plasma...