Module 1

• Opium was discovered in Greece form the opium poppy, and contains morphine and codeine substances.
• Morphine makes up 10% of opium, and is able to relieve pain intensely
• Codeine makes up 0.5% opium, and is used for pain relief, and is a constituent of Tylenol.
• Ebers papyrus is a textbook for drugs in Egypt, and studied purgatives, which are drugs used to induce bowel movement. Senna is an example of such drug
• Ma Huang is a drug developed in China, and is used for coughs and fevers.
• Ephedrine is isolated from Ma Huang, and is used to treat asthma
• Curare is a plant-derived drug from the Amazon, where Indigenous people dipped their arrows as a poison by causing paralysis on muscles. It was eventually used in anesthesia for surgery in small doses.
• Ergot is a poisonous fungus that affected the nervous system (hallucinations), cardiovascular system (constriction of blood vessels), and reproductive system (violent contraction of the uterus)
• Ergotamine is a drug derived from Ergot, and is used for treating migraines by constricting pulsating blood vessels.
• Ergonovine was a drug derived from Ergot used to hasten birth, but is too dangerous nowadays. It can be used to arrest uterine bleeding after birth.
• Peyote is a soothing drug used in religion, which causes a mystical feeling similar to LSDs, and is thought to facilitate communication with their Gods
• A drug is any substance which is received by a biological system that is not received for nutritional purposes, and which influences the biological function of the organism.
• There are two types of drugs: drugs acting on the brain, and drugs acting on infectious diseases
• Gram positive bacteria is with thick cell walls and no outer membrane (acted on by Penicillin)
• Gram negative bacteria have thin cell walls and an outer membrane (acted on by streptomycin)
• Drug development can be divided into 5 key steps: basic research and drug discovery, preclinical trials, clinical trials (phases 1-3), Health Canada review and manufacturing, post market surveillance and phase 4 clinical trials.
• Step 1 of drug development involves drug discovery and basic research. Identify the target (ie pain receptor), and study the target (identify whether it is a lead compound or not, and determine its efficacy)
• Step 2 of drug development involves preclinical testing. This includes animal studies to test safety and toxicity, as well as pharmacokinetics.
• Step 3 of drug development is clinical trials. There are three things that clinical trials entail: Proof of safety (must submit proof to the government), methodology (methodology of the proposed trial), and investigation (if submission is approved, highly trained investigators will investigate the drug in humans
• Phase I clinical trials evaluate absorption, distribution, elimination, and adverse affects of the new drug. These trials test one or two doses to determine the tolerability
• Phase II clinical trials are done to determine whether the drug is effective in treating the condition for which it is recommended, and are conducted on patients with the disease.
• Phase III clinical trials (randomized controlled trials) are the main studies for the marketing and licensing of the drug, and involves enrolment, treatment allocation, and results.
• Bioequivalence is a term used compare generic name drugs from brand name drugs. The same generic name drugs go under strict regulations to make sure they have the same ingredients, and therefore the same affect as a brand name drug for the same drug (bioequivalence) .
• Step 5 of drug manufacturing involves Post-Market Surveillance (phase IV clinical trials). Surveillance of the drug is required after the drug is released for general use in the case of delayed risks or risks that are less frequent during phase III clinical trials.
• Receptors are the main type of drug target, and are normally bound to and activated by endogenous ligands (hormones and neurotransmitters). The location of the receptor depicts whether the response will be beneficial or detrimental (ie opioid activates receptors in the brain, but also activates receptors in gastrointestinal tract, causing adverse affects).
• Drug targets that are not receptors can be chemical reactions and physical chemical forces.
• Drugs that act on receptors usually act as agonists (binding to and stimulating the receptor) and antagonists (bind but block the response at a receptor).
• Drug response is the second factor to consider when analyzing a drug's action. Usually the pharmacological effect experienced by a drug increases as the dose increases. This is called the dose-response relationship.
• The threshold of a drug is the dose that results in a response, that usually occurs at higher than low doses. The therapeutic dose is when the threshold is reached, and a small increase in dose will have a big effect. Maximal effect is attained when increasing the dose has no further effect on the organism.
• A dose response curve is a representation of how much drug you need in the body to see a specific effect, and has log dose on the x-axis, and response percentage on the y-axis.
• The third factor in analyzing a drug's action is its efficacy and potency.
• Efficacy is the maximum pharmacological effect that can be produced from a drug
• Potency is the dose of a drug required to produce 50% of the maximal response for that drug.
• Therapeutic range is the range of drug dose that keeps blood concentration of a drug above the minimum concentration that produces a desirable response, but below the concentration that produces a toxic response.
• Pharmacokinetics refers to the movement of a drug into, through, and out of the body. It involves 4 steps: Absorption, Distribution, Metabolism and Excretion (ADME)
• Topical are drugs applied directly on a place of the body. This includes on the skin, through the skin, and inhalation (lungs).
• Enteral administration is a drug applied via the gastrointestinal tract, via mouth or an artificial opening. This includes mouth, rectum, and sublingual and buccal.
• Parental administration is a drug applied by bypassing the GI tract. This includes intravenous, intramuscular, and subcutaneous
• Bioavailability is defined as the fraction of administered dose that reaches the systemic circulation (blood) in an active form.
• Distribution is the movement of a drug from the blood to the site of action and other tissues. Most drugs will reach all tissues and organs regardless of the target site.