Scientific Medicine & Pharmacokinetics

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Questions and Answers

During which period did what we recognize as 'science' begin to take shape?

Eighteenth Century

Seventeenth Century

Nineteenth Century

Early Middle Ages – 1200s CE (correct)

Which philosophical approach emphasizes acquiring knowledge through reason rather than received ideas?

Rationalism (correct)

Empiricism

Inductivism

Positivism

What significant shift occurred in Western medicine due to new scientific approaches?

End of humoral theory (correct)

Introduction of surgical methods

Reevaluation of herbal remedies

Emphasis on religious healing practices

Which of the following concepts relates to developing laws from observable phenomena?

Inductivism Signup and view all the answers

What impact did scientific methods have on the practice of medicine in the nineteenth century?

Allowed for measurable causes of disease Signup and view all the answers

What is the primary role of drug-metabolizing enzymes (DMEs) in the body?

To transform lipophilic drugs into water-soluble metabolites Signup and view all the answers

During metabolism, how does the structure of a drug typically change?

It is often converted into less active metabolites Signup and view all the answers

Which of the following best describes a pro-drug?

A drug that is inactive until metabolized Signup and view all the answers

What is a common consequence of drug metabolism?

Reduction of drug activity through structural modification Signup and view all the answers

Which of the following statements about metabolites is true?

Some metabolites can contribute to the pharmacology of the parent drug Signup and view all the answers

What distinguishes fortified wine from regular wine?

It contains added spirits, increasing the alcohol content significantly. Signup and view all the answers

What is a significant characteristic of ethanol's pharmacokinetics?

Ethanol's amphipathic nature allows for rapid absorption and wide tissue penetrance. Signup and view all the answers

Which of the following is NOT a source for whiskey?

Potatoes Signup and view all the answers

How does food intake affect alcohol absorption?

Food can delay gastric emptying and thus slow down alcohol absorption. Signup and view all the answers

Which combination of ingredients best describes port?

Wine and neutral grape spirit Signup and view all the answers

What does pharmacodynamics refer to?

The effects of drugs on the body Signup and view all the answers

What does the term 'ADME' stand for in pharmacology?

Absorption, Distribution, Metabolism, Excretion Signup and view all the answers

What does 'F(oral)' represent in the context of drug absorption?

The fraction of the drug reaching systemic circulation Signup and view all the answers

A drug with a molecular weight greater than 600 g/mol is likely to have which of the following issues?

Poor absorption Signup and view all the answers

What is the primary reason for drugs having a therapeutic window?

To indicate effective dosing levels Signup and view all the answers

Why might drug bioavailability be less than 100%?

Some of the drug remains unabsorbed or is metabolized in the gut Signup and view all the answers

What does the term 'plasma concentration-time profile' help define?

The therapeutic window of a drug Signup and view all the answers

Which type of administration is generally considered most convenient for taking medicines?

Oral administration Signup and view all the answers

What is a key factor that affects a drug's ability to cross lipid-rich cell membranes?

Lipophilicity of the drug Signup and view all the answers

What is the main goal of pharmaceutical innovation regarding drug safety?

To widen the therapeutic window Signup and view all the answers

What primarily influences the peak BAC (Cmax) after alcohol ingestion?

The type of beverage and amount ingested Signup and view all the answers

Which factor contributes to females experiencing a higher peak BAC compared to males?

Females have a smaller body size and lower TBW. Signup and view all the answers

What is the primary enzyme responsible for alcohol metabolism in the liver?

Alcohol dehydrogenase (ADH) Signup and view all the answers

What is the typical metabolic rate of alcohol in a 70 kg human?

8 grams per hour Signup and view all the answers

Which of the following describes the role of NAD in alcohol metabolism?

Acts as a cofactor for alcohol dehydrogenase and aldehyde dehydrogenase Signup and view all the answers

What is a potential consequence of a polymorphism in the ALDH2*2 gene?

Decreased metabolism of acetaldehyde Signup and view all the answers

Which route is responsible for the excretion of a small quantity of alcohol?

Via urine by the kidneys Signup and view all the answers

What percentage of alcohol is typically exhaled directly in breath?

5% Signup and view all the answers

Study Notes

Scientific Medicine & Humoral Theory

Scientific thought, as we know it today, truly flourished around the 1200s CE, with the 18th century marking a significant rise in scientific approaches across various fields.
Scientific methods were applied to medicine, particularly in the 19th century, leading to a shift from the traditional humoral theory of disease.
Humoral theory's limitations became evident as it lacked measurable evidence.
New scientific approaches focused on identifying measurable causes of diseases, their patterns, durations, and responses to specific treatments, making medicine more effective and less risky.

Pharmacokinetics: How the Body Processes Drugs

Pharmacology involves studying how drugs interact with the body.
Pharmacokinetics (PK) focuses on the movement of drugs within the body, including absorption, distribution, metabolism, and excretion (ADME).
Pharmacodynamics (PD) focuses on how the drug affects the body.
A drug's specific properties determine its PK and PD profiles.
Understanding drug concentrations in blood over time (plasma concentration-time profile) is crucial for determining the "therapeutic window," the range where the drug effectively treats the condition without causing harm.

Absorption: How Drugs Enter the Body

The oral route is the most common method of drug administration.
Drug absorption involves the movement of ingested drug molecules from the gastrointestinal (GI) tract into the portal blood.
The oral bioavailability (F) refers to the fraction of the ingested dose that reaches the systemic circulation.
Factors like the drug's size, lipophilicity (greasiness), and charge can impact its bioavailability.
Larger molecules, hydrophilic drugs, and ionized drugs tend to have poor bioavailability due to their difficulty crossing lipid-rich cell membranes in the gut wall .

Metabolism: How the Body Modifies Drugs

The body uses drug-metabolizing enzymes (DMEs) to convert drugs into water-soluble metabolites for easier excretion.
DMEs are found in various tissues, including the gut wall, liver, kidney, and other tissues.
Metabolism often reduces a drug's activity by altering its structure, but some metabolites retain pharmacological activity.
Some drugs are inactive until metabolized (pro-drugs) whereas some drug metabolites can be toxic.

Alcohol: Pharmacokinetic Considerations

Ethanol, the alcohol in alcoholic beverages, exhibits amphipathic properties, meaning it has both water-loving (hydrophilic) and fat-loving (lipophilic) characteristics.
These properties contribute to its rapid absorption and wide tissue penetration.
Alcohol is absorbed primarily from the upper intestine and stomach.
Food can delay gastric emptying and alcohol absorption.
The peak blood alcohol concentration (BAC) depends on the type of beverage and the amount consumed.
Alcohol is distributed throughout the body via the bloodstream with a greater presence in the total body water (TBW) due to its high water solubility.
Women tend to have higher peak BACs than men due to their smaller body size, lower proportion of TBW, and potentially lower levels of EtOH metabolizing enzymes.

Alcohol: Metabolism & Elimination

Alcohol metabolism primarily occurs in the liver via enzymes like alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH).
This metabolism requires the cofactor NAD (nicotinamide adenine dinucleotide).
Under normal conditions, alcohol metabolism is saturated due to limited liver NAD capacity, resulting in a fixed rate of alcohol metabolism, approximately 8g/hr in a 70kg person.
Genetic variations in ADH and ALDH genes, like the ALDH2*2 polymorphism in East Asians, can influence alcohol metabolism and acetaldehyde levels.
Small amounts of alcohol are excreted directly in the urine and breath.

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Description

Explore the evolution of scientific medicine from humoral theory to modern pharmacology. This quiz covers key concepts in pharmacokinetics, including how drugs move through the body and their interactions. Test your knowledge on how scientific methods transformed medicine.