53 Questions
What factors govern the ability of a drug to dissolve when administered orally?
Type of tablet coating
What must a drug pass through after oral administration before reaching the site of action?
Multiple barriers, alternate sites of storage, and metabolic destruction
How can the dissolution rate of a drug be varied?
By adjusting the type of tablet matrix
What is essential for a drug to do to reach its desired target?
Avoid chemical modification
What is one of the main concerns related to a new drug molecule's passage through the gastrointestinal tract?
Being unable to survive in the intestinal tract due to enzyme degradation
Why is mesalamine not effective when administered orally?
It is metabolized to inactive forms before reaching the colon
How does olsalazine address the issue of mesalamine's ineffectiveness when taken orally?
It is a dimer of mesalamine that gets cleaved by intestinal bacteria to release mesalamine
How does chloramphenicol utilize its water solubility advantage according to the text?
To interact with taste receptors on the tongue causing bitterness
Where does drug distribution involve partitioning between the aqueous environment and lipid bilayer cell membrane?
Gastrointestinal tract and mucosal cells
Why might parenteral administration be preferred in some cases?
To bypass the intestinal barrier
What is a disadvantage of intravenous administration in terms of drug distribution?
Rapid distribution throughout the body
Why do subcutaneous and intramuscular injections show slow distribution of the drug?
Diffusion from injection site into systemic circulation
What purpose does adding the palmitic acid moiety serve in chloramphenicol palmitate?
To reduce the parent drug's water solubility
What is a common characteristic of prodrugs like olsalazine and chloramphenicol palmitate?
They are cleaved to smaller compounds to become active
How does the ester prodrug form of enalapril compare to the active form enalaprilic acid?
The prodrug is more effectively absorbed orally
Why must drugs intended to act systemically pass through the gastrointestinal mucosal barrier?
To increase drug absorption into venous circulation
What factors influence the ability of a drug to dissolve when administered orally?
Chemical structure, particle size, crystal form, tablet coating, tablet matrix
Why is it important for a drug administered orally to go into solution?
To facilitate passage through the gastrointestinal mucosa
How can the dissolution rate of a drug be controlled?
By varying the dosage form and physical characteristics
What is a key purpose of chemical modification in drug development?
To help the drug reach its desired target more effectively
What is the purpose of adding the palmitic acid moiety to chloramphenicol to create chloramphenicol palmitate?
To mask the intense bitter taste of the drug
What role do prodrugs like olsalazine and chloramphenicol palmitate play in drug distribution?
They are inactive initially but are converted to active drugs within the body
Why is enalapril administered as the ethyl ester prodrug rather than the active enalaprilic acid?
To improve oral absorption compared to the active form
Why must drugs intended to act systemically pass through the gastrointestinal mucosal barrier?
To reach the bloodstream and distribute throughout the body
What is a disadvantage of intravenous administration in terms of drug distribution according to the text?
Rapid distribution throughout the body
Why might parenteral administration be preferred in some cases based on the text?
To bypass the intestinal barrier
What is an obstacle faced regardless of the route of administration as mentioned in the text?
Direct drug placement in tissue depots
Where does drug distribution involve partitioning between lipid bilayer cell membranes based on the text?
Cell membrane of mucosal cells
What happens to the concentration of thiopental below its effective concentration following administration?
It disappears into tissue protein
How do structural changes in the barbiturate series affect the duration of action and CNS depression?
Decrease duration of action and CNS depression
What characterizes the barbiturates with the slowest onset and longest duration of action?
They enter and leave the CNS slowly due to polar side chains
How does redistribution of thiopental into body fat affect its pharmacological response?
Reduces the pharmacological response
Olsalazine is a monomer of the pharmacologically active mesalamine.
False
Chloramphenicol is effective orally because it is resistant to digestive enzymes in the intestinal tract.
False
Parenteral administration always involves the oral route for drug delivery.
False
The dimeric form of olsalazine is cleaved into two equivalents of mesalamine by bacterial enzymes in the intestine.
True
Protein binding never affects the availability of a drug for biotransformation or receptor interaction.
False
The half-life of a drug in the body is not related to its duration of action.
False
Drug-protein binding interactions can lead to increased prothrombin time and potential hemorrhage.
True
The more hydrophilic a drug is, the more likely it will concentrate in tissue depots.
False
Methylprednisolone sodium succinate is the water-insoluble sodium salt of succinate ester.
False
Acitretin, with a 120-day terminal half-life, is recommended for pregnant women.
False
Proteins usually break down serum proteins in the systemic circulation.
False
Etretinate has a shorter half-life than acitretin.
False
Thiopental's duration of action can be increased by favoring partitioning into lipid tissue stores.
False
Barbiturates with polar side chains have a slower onset of action compared to lipophilic thiopental.
True
The remaining thiopental diffuses back into tissue depots for a pharmacological response.
False
Barbiturates with a slow onset of action contain lipophilic side chains.
False
How does protein binding of a drug impact the availability for biotransformation and receptor interaction?
Limits the amount available for biotransformation and receptor interaction
In what form does the trypanocide suramin remain in the body, affecting its duration of action?
Protein-bound form
What effect can drug-protein binding have on anticoagulant medications like warfarin?
Increases effective concentration
What role do tissue depots play in drug distribution?
Store drugs for prolonged periods
How does the lipophilicity of a drug relate to its concentration in tissue depots?
More lipophilic drugs concentrate less in tissue depots
Explore the mechanism of how palmitic acid moiety is used as an ester in drug distribution to mask the intense bitter taste of chloramphenicol. Learn how the ester linkage is hydrolyzed by digestive esterases to release the active antibiotic.
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