Principles of Pharmacology Flashcards
Curare
arrows dipped in it and used as a poison causing paralysis and death, used to relax muscles during surgery
Ergot
grows on heads of rye and used as a poison, ergotamine used as a migraine medication causing vasoconstriction, ergonovine used to hasten uterine contractions and stop uterine bleeding after childbirth
Reserpine and Chlorpromazine
isolated from rauwolfia plants to reduce tension, anxiety and lower bp; chlorpromazine used preferentially to treat mentally ill
LSD
synthesized by Albert Hoffman; similar in structure to ergotamine and ergonovine causing psychedelic effects and supported the idea that mental illness might be due to chemical imbalance
Anaesthetics
NO used in extraction of teeth and ether used as anesthesia during surgery
Organoarsenicals
Paul Ehrlich is the father of chemotherapy; lead to the cure of syphilis bc these compounds selectively bind to parasites
Sulfa Drugs
introduced by Gerard Domagk for the treatment of bacterial diseases
Penicillin
Alexander Flemming discovered penicllin as the first antibiotic against gram positive bacteria
Streptomycin
Selman Waksman discovered streptomycin as an antibiotic effective in treating tuberculosis and gram-negative bacterial infections
Drug discovery
drug target is determined and pharmacological effects observed; if promise is shown safety and efficacy studies are done
Pre-clinical studies
toxicology study to determine the effects on organ systems that are not the target organ, and pharmacology study to determine the detailed MOA
Clinical Trial Initial steps
proof of safety and efficacy and methodology of proposed clinical trial is submitted and reviewed
Clinical Trial Phase 1
conducted in a limited number of healthy individuals to carefully examine MOA and adverse effects; efficacy not tested
Clinical Trial Phase 2
conducted in patients with the disease the drug is designed to treat to test the efficacy
Clinical Trial Phase 3
controlled randomized clinical trial to license and market drug and tested in a large group of people for more extensive periods of time (where the target pop, inclusion/ exclusion, placebo, etc. come into play)
Clinical Trial Phase 4
post-marketing surveillance; risks that are delayed or less frequent might not appear in phase 3
Drug Targets
drugs bind to receptors of certain tissues and can be agonists (stimulate receptor) or antagonist (block response at receptor), chemical reactions (antacids) and physical chemical factors (like cholestyramine binding to bile acids)
Drug Efficacy
max pharmacological effect that can be produced independent of the potency
Drug Potency
the dose of the drug required to produce a response of a certain magnitude; normally 50% of the maximal response for that drug
Therapeutic Index and Therapeutic Range
the relationship between concentrations causing adverse effects (TD) and those causing desired effects (ED) (the larger the greater); range refers to the dose that keeps the blood conc. of the drug above minimum conc. that produces a desirable effect but below the conc. that produces a toxic response
Dose Response curve
once threshold is reached and a certain number of receptors have been activated, a small increase in dose will have a large change in response (linear portion) and also where ED50 occurs (dose that will result in 50% of maximal effect, or dose that is effective in 50% of pop)
On the skin (topical administration)
drugs applied to skin to treat mild to moderate skin conditions
Through the skin (topical administration)
application of drug to the skin for absorption into general circulation; convenient and delivers steady drug supply while bypassing internal enzymes, but can be expensive and a local irritant
Inhalation (topical administration)
gaseous anesthetics, as well as steroids and other drugs for lung disease inhaled, the doses are small and toxicities associated with oral medications are avoided, but it requires proper use by the patient
Mouth (enteral administration)
most common, convenient, inexpensive and non-invasive means that can be self administered; first pass through the liver which reduces the amount of active drug left to enter circulation and there is variable absorption between patients; slow onset of 0.5-1h
Rectum (enteral administration)
systemic or local effect for patients who are vomiting and a less invasive approach for comatose patients; digestive enzymes are bypassed, but not all drugs are available as suppositories and absorption is slow, incomplete and variable
Sublingual and Buccal (enteral administration)
under the tongue and under the cheek and bypasses enzymes in the stomach, intestine and livers but are not always adequately absorbed and will then act as an oral drug; rapid 1-4 min onset
Intravenous (parenteral administration)
injected into blood to produce an immediate response (15-30 sec) for drugs that are poorly absorbed but can have intense response, is costly and prep must be sterile
Intramuscular (parenteral administration)
drug injected deep into muscle; 10-20 min onset
Subcutaneous (parenteral administration)
drug injected into deepest layer of skin; 15-30 min onset
Bioavailability
fraction of the administered drug that reaches the systemic circulation in an active form
Absorption
crosses biological membranes via diffusion, or active/ mediated transport
Distribution
movement of drug from blood to the site of action and other tissues; the greater the blood flow the more rapidly the drug reaches that organ
Metabolism
conversion of drug to its metabolites that are usually devoid of pharmacological actions and mostly occurs in the liver but also in most other organs; first P450 unmasks or add functional group, then a large water moiety is added to make it water soluble for excretion
Excretion
majority through kidneys (needs to be water soluble), GI tract, lungs, saliva and sweat, breast milk
Drug Interactions
increased or decreased absorption of a second drug, can block the inactivation of a second drug and increase its effect, can facilitate the excretion of a second drug and decrease its effect
