Flashcards in Section A Deck (82):
What are the symptoms of ergot poisoning?
Burning in limbs (St. Anthony's Fire)
Constriction of blood vessels
What two active principles have been isolated from ergot? What are their modern uses?
Ergonovine (arrest bleeding AFTER childbirth)
What accurate observations did the Ebers papyrus contain?
Information about purgatives (to cause bowel movements); recommended drugs included castor oil, figs and senna
What compounds can be isolated from opium (in what amounts)?
10% morphine (morphine may be chemically converted to heroin)
What compound is isolated from the plant Colchicum? What is its modern use?
Colchicine is extracted from the plant; used in the treatment of gout
Who isolated a compound from digitalis purpurea? What are its uses?
William Withering isolated digitalis drugs from foxglove for the treatment of weak heart muscles or disordered rhythms
What compound can be isolated from foxglove?
Digoxin (Lanoxin) can be isolated from foxglove
Who discovered amyl nitrate? What was it used for?
Lauder Brunton discovered the use of amyl nitrate in the treatment of angina pectoris; one disadvantage is that it is short lived
Who discovered nitroglycerin?
Describe nitroglycerin's mechanism of action.
Nitroglycerin is used in the treatment of angina pectoris. It dilates blood vessels in the heart and elsewhere in the body.
What compound can be isolated from the Cinchona tree? What are its uses?
Quinine may be isolated for the treatment of malaria
What drug is related to quinine? What are its uses?
Quinidine may be used for the treatment of arrhythmias
What can be isolated from the rauwolfia plant? What are its uses?
Reserpine can be isolated from the plant. It was used for the treatment of uncontrollable patients (now there are better drugs) and still used in the treatment of hypertension
Which modern drug is a suitable replacement for reserpine?
Who discovered LSD?
Which compounds are structurally similar to LSD?
Ergotamine and ergonovine
The father of chemotherapy; discovered organoarsenicals, which cured syphilis (Salvarsan)
Introduced sulfa drugs
Discovered the first antibiotic, penicillin (treatment of Gram-positive bacteria)
Discovered streptomycin (tuberculosis and Gram-negative bacteria)
Showed the pain-releiving effects of nitrous oxide
Gave public demonstrations of nitrous oxide
Dentist; used nitrous oxide during tooth extraction
Pointed out ether has similar properties as nitrous oxide
Performed the first surgery under ether anaesthesia
List drug advertising techniques (6).
Catch audience attention
Use of celebrities or authority
Offering an easy solution to problems
Discredit competing drugs; praise own drug
What are the steps to introducing a new drug into therapeutics?
1. Proof of safety and efficacy of drug in several animal species to government regulatory agency
2. Methods for proposed human clinical trial
3. Clinical trials by pharmacologists (P1-P4)
What is phase 1 of a clinical trial?
In a limited number of healthy volunteers the absorption, distribution, elimination and adverse effects are tested.
What is phase 2 of a clinical trial?
Proof of concept - drug is tested to see if it is effective in treating the condition for which it is recommended; safety is studied
What is phase 3 of a clinical trial?
Drug is testing in a larger number of people (1000+); safety and efficacy examined
What is phase 4 of a clinical trial?
Drug released for general use; post-marketing surveillance for delayed risks
What are placebo effects?
Effects which occur as a result of drug administration; unrelated to pharmacological effects
Studied placebo effects; found satisfactory relief in 35% of patients
What are conditions that may be responsive to placebos?
Angina pectoris, common cold, anxiety, cough, mood changes, headache, seasickness, post operative wound pain, asthma, hypertension, mental depression
What should a new drug always be compared to (if available)?
An older drug of proven value; placebo if nonexistent
What is cross-over design?
Group A - new drug
Group B - old drug (or placebo)
Group A - old drug (or placebo)
Group B - new drug
What is parallel design?
Group A - new drug
Group B - old drug (or placebo)
What is the best, unbiased experimental design?
Parallel design (with old drug), randomized group assignment, double-blind design, controlled elements
Potency refers only to the amount of drug that must be given to obtain a particular response
The maximum effect that is obtainable with a given drug
Define selective toxicity.
Injury to one kind of living matter without harming some other kind
Pasteur and Koch
Demonstrated that diseases of many types are caused by microbes
How are sulfanilamides selectively toxic?
Disrupt the manufacture of folic acid through resemblance to PABA
What compound do bacteria utilize to manufacture folic acid?
PABA (para-aminobenzoic acid)
Something that acts against substances required for the metabolism of an organism
Describe chemical differences between a normal cell and a cancer cell.
Certain cancer cells cannot manufacture asparagine (an aa required for protein synthesis) and require it from the blood. Cancer cells also divide continuously (while most normal cells are in a non-dividing state)
What are twin hazards associated with the widespread distribution of drugs?
Accidental poisoning (mostly children under 5) and suicide
List some of the most common items accidentally swallowed by children.
aspirin, acetaminophen, bleach, diaper-pail deodorizer, chocolate flavoured laxatives, children's fever drops, cough syrups, tranquilizers, birth control pills and cigarette butts
What is the major drug group implicated in suicide?
List 4 types of adverse effects to drugs.
1. Extension of therapeutic effect
2. Unrelated to main drug action
4. Drug allergy
Define idiosyncrasy in terms of an adverse effect to drug consumption.
The genetic makeup of some individuals renders them sensitive to the adverse effects of some drugs. For example, some patients lack a blood enzyme required to inactivate certain drugs
Define the 3 P's of drug introduction
Panacea - Assumption that drug is a major new advance
Poison - Adverse effects revealed; sales drop
Pedestrian - Benefit/risk ratio easier to assess; realization that drug is "average"
List the reasons as to why a new drug later turns out to be toxic (4).
1. The toxic reaction may be a rare event
2. The toxic reaction may only appear after the drug has been in prolonged use
3. Toxic effect not detectable in animals
4. Toxic effect unique to a certain period (ex. pregnancy)
Dose toxic to 50% of the population of animals
Median effective dose; dose which is effective in 50% of the population
What ratio does the therapeutic index equal?
What does a high therapeutic index mean?
Greater safety of the drug, wider safety margin
What does a low therapeutic index mean?
Low drug safety, narrow safety margin
If given the same dose, why would blood concentration of a drug differ between individuals?
1. genetic factors
2. environmental factors
4. presence of other drugs
What are the enteral routes of drug administration?
1. Drug taken by mouth (oral)
2. Rectal administration
3. Under the tongue (sublingual)
What are the parenteral routes of drug administration?
5. spinal canal
List disadvantages of intravenous administration.
1. A drug injected into a vein cannot be retrieved
2. If given too rapidly, can lead to disaster
3. Danger of infection is sterile technique is not used
What are poisonous materials that can be absorbed through the skin?
Parathion and malathion (insecticides) and nicotine
Describe how a drug allergy arises.
First time administered - drug forms an antigen; antibody is generated
Second time administered - previous antibodies combine with antigens, provoking an adverse reaction
What is the most common route of drug administration?
Describe the steps a oral drug must undergo before it exerts an effect.
1. Disintegrates into small particles; dissolves in fluid of stomach/intestine
2. Absorption through stomach or intestine wall
3. Carried via bloodstream to site of action
What is the major site of drug absorption (orally)?
What tests does the government require for tablets?
1. Must contain adequate amounts of the active chemical
2. Must disintegrate in a test tube
The percentage of drug contained in a drug product that enters the systemic circulation in an unchanged form after administration. Also considers the rate of entry.
List the processes that occur after a drug has been orally administered.
Where could a drug affecting the brain redistribute to (during termination)?
Muscle or fat
Where are most drugs excreted from?
How is a water soluble drug excreted?
In urine from the kidneys
How is a fat soluble drug excreted?
It is filtered through the kidneys, but then reabsorbed via the renal tubules. It is then transported to the liver, which converts to a more water soluble product (via enzymes such as cytochromes P450)
What is the main enzyme group responsible for converting fat-soluble drugs to water-soluble products?
Describe drug interactions caused by absorption.
1. One drug may combine with another in the stomach/intestine and form a complex which cannot be absorbed into blood
2. A drug increasing intestinal movements may speed the passage of a second drug
3. A drug may hinder intestinal movement, increasing drug absorption
Describe drug interactions caused by displacement.
A second drug may displace the first drug from its binding site on a blood protein (free drug exerts more effect)
Describe drug interactions caused by changes in liver handling.
Drug B may block the mechanisms in the liver responsible for the inactivation of Drug A. Drug B may also speed up the inactivation of Drug A.
Describe drug interactions caused by changes in excretion.
Drug B may hinder the excretion of Drug A by the kidneys. Drug B may facilitate the excretion of Drug A by the kidney.
Describe interactions of drugs with potentially toxic substances in food.
Tyramine (in old cheeses) is broken down in the liver by an enzyme known as monoamine oxidase (MAO). Some depression drugs are MAO inhibitors, which leads to excess tyramine (causing high BP)
What is tyramine?
Tyramine is contained in foods such as old cheeses. It is related to adrenaline and raises BP. It is broken down in the liver by monoamine oxidase (MAO).