Toxicology Metabolism of Chemicals Quiz

What is the purpose of determining the Therapeutic Index (TI) of a drug?

To compare the effective dose to the toxic dose of the drug (correct)
To determine the maximum tolerated dose of the drug
To evaluate the safety of the drug formulation
To assess the drug's potency and efficacy

What is the common method used to derive the Therapeutic Index (TI) of a drug?

Using the maximum tolerated dose
Using the 75% dose-response points
Using the 25% dose-response points
Using the 50% dose-response points (correct)

Which of the following factors can affect the LD50 (Lethal Dose 50%) of a drug?

Effective dose and toxic dose
Dosage formulation and experimental procedure
Route of administration and species (correct)
Therapeutic response and toxicity

What is the significance of specifying the route of administration when reporting the LD50 of a drug?

To ensure the LD50 value is comparable across different studies (A) Signup and view all the answers

What is the relationship between the Therapeutic Index (TI) and the relative safety of a drug?

The higher the TI, the more safe the drug is (D) Signup and view all the answers

Why do governmental agencies still regard the LD50 as the sole measurement of the acute toxicity of materials, despite the many variables affecting its determination?

The LD50 is a simple and standardized test that provides a consistent metric (D) Signup and view all the answers

What is the primary concern in cases of acute toxicity exposures?

Death (A) Signup and view all the answers

What is the difference between LD50 and LC50?

LD50 measures the median lethal dose, while LC50 measures the median lethal concentration. (C) Signup and view all the answers

What is the purpose of determining the LD0 in toxicology studies?

To find the dose at which no individuals are expected to die. (C) Signup and view all the answers

Why must methanol be oxidized to its intermediate metabolites before producing its most serious toxic symptoms?

To convert it into a more toxic compound (C) Signup and view all the answers

What is the significance of the threshold for toxic effects in toxicology?

It indicates the dose at which the body's ability to detoxify a xenobiotic or repair toxic injury has been exceeded. (C) Signup and view all the answers

What is the purpose of determining the LD10 in toxicology studies?

To find the dose at which 10% of individuals will die. (C) Signup and view all the answers

How does the presence of hepatic or renal disease affect the toxicity of a chemical?

It increases the toxicity (C) Signup and view all the answers

Why are opiates and other chemicals that cause respiratory depression more hazardous in persons with head injuries?

They lead to hypercarbia and increased intracranial pressure (C) Signup and view all the answers

What is the difference between an effective dose (ED) and a lethal dose (LD) in toxicology?

An ED refers to a beneficial effect, while an LD refers to a harmful effect. (D) Signup and view all the answers

In what age group do most accidental poisonings occur according to the text?

Less than 10 years (A) Signup and view all the answers

Why should certain drugs be avoided in therapy for individuals with severe renal disease?

To avoid increasing drug toxicity (C) Signup and view all the answers

Which of the following conditions makes chemicals more toxic in general according to the text?

Renal disease (B) Signup and view all the answers

What does the abbreviation NOAEL stand for?

No Observed Adverse Effect Level (C) Signup and view all the answers

The LOAEL refers to:

Low Observed Adverse Effect Level (C) Signup and view all the answers

What is the acceptable daily intake (ADI)?

The level of daily intake that does not produce an adverse health effect (C) Signup and view all the answers

What are reference doses (RfDs) used for by the EPA?

For health effects that are thought to have a threshold or low dose limit for producing toxic effects (C) Signup and view all the answers

What is the relationship between the RfD and the NOAEL?

RfD = NOAEL / Safety factors (D) Signup and view all the answers

What do the terms NOEL and LOEL stand for?

No Observed Effect Level and Lowest Observed Effect Level (D) Signup and view all the answers

What is the primary reason for less chemical per unit of blood being available for elimination by dialysis when Vd is greater than 250-300 L?

Decreased plasma water flow (A) Signup and view all the answers

Which of the following is not listed as an indication for hemofiltration according to the text?

Healthy individuals for preventative measures (D) Signup and view all the answers

What type of transport of solutes occurs during continuous arteriovenous hemofiltration?

Convective transport (C) Signup and view all the answers

Which adverse reaction is NOT associated with hemofiltration as per the text?

Allergic reactions (D) Signup and view all the answers

What can induce a convective transport of solutes through a membrane during hemofiltration?

Arteriovenous pressure difference (B) Signup and view all the answers

What relative molecular weight allows compounds to have high permeability during hemofiltration?

$<$ 40,000 daltons (A) Signup and view all the answers