WorksheetsPharmacokinetics I
Total questions: 41
Worksheet time: 24mins
Which of these are parenteral routes of drug administration?
Injection
Inhalation
Transdermal
Oral
Which of these are topical administration?
Evacuant enema
Local anaesthetic cream
Bronchodilator(salbutamol)
Testerone buccal
Which of these are systemic?
Testerone buccal
Diazepam rectal
Eye drop
Oral tablets
Pros of oral delivery
Convenience
Painful
Mostly safe
Self administered
Repeated and prolonged use
Cons of oral delivery
Suitable for emergency
Highly irritant drugs
High first pass metabolism
Can be destroyed by digestive juice
Suitable for baby
Pros of sublingual or buccal administration
Bypass gastric and hepatic metabolism
Slow absorption
Drug stability due to neutral pH
Self-administered
Cons of sublingual/buccal
Inconvenience
Small dose
Presence of saliva that may wash away drug
Suitable for children
Pros of rectal administration
No metabolism due to absent of enzymes
Suitable for seizure patients
Slow absorption
Some bypass hepatic and gastric metabolism
Cons of rectal administration
Erratic absorption
Unsuitable for irritant drugs
Less patient compliance
What administration is used for drugs that are inactivated in the gut and liver or poorly absorbed through mucosal membrane?
(a)
Pros of IV
Bypass gastric and hepatic metabolism
Slow
Total dose
Unsuitable for irritant drugs
Cons of IV
Risk of anaphylaxis
Can be self administered
Painful procedure
Increase chance of overdose
Pros of Intramuscular (IM)
Fas absorption than but slower than IV
Given in small amounts
Does not bypass gastric and hepatic metabolism
Cons of IM
Painful
May cause injection fibrosis
Self administer is possible
Pros of Subcutaneous (SC) administration?
Small volume
Fast absorption but slower than IM
Self administered is possible
Bypass gastric and hepatic metabolism
Cons of Subcutaneous
Absorption dependent to subcutaneous blood flow
Suitable during emergency
Absorption affected vasoconstriction
Transdermal such as testerone gel and GTN patch is beneficial as it is
Self Administration possible
Avoid first pass effect
Convenient
Cons of Transdermal
Cause skin irritation
Unlimited absorption
Falling patch
Inhalational route of drug administration
can cause local irritation
slow absorption
erratic absorption
significant first pass metabolism in the lungs
Hydrophilic compound or ionised compound can pass through renal tubule membrane
True
False
Log P octanol / water represents
(a)
Ideal Log P value for oral drugs to compromise between permeation and clearance
2
9
1000
1
Factors affecting rate of passage in Solute Carrier Transporter
Concentration gradient of drug
Quantity of macromolecule
Rate of reversible interaction between drug and carrier
Penicilin and probenecid compete for the same (a) due to their similar structure
Secondary active transport use electrochemical gradient as a source of energy
True
False
Macromolecules such as Vitamin A, D,E ,K, liposomes, and protein are transported by
Aqueous diffusion
Pinocytosis
Secondary Active transport
Insulin is destroyed by proteolytic enzyme while Penicillin G is destroyed by
(a)
Following are physiochemical properties that influence drug absorption
Stability of drugs in GI
Lipophilicity
Particle Size
Degree of ionisation
First pass metabolism
What are added to a formulation to provide certain functional properties?
(a)
Ionisation of drugs decrease absorption due to its ability to permeate membrane reduced
True
False
Urinary acidification accelerates excretion of weak
bases
acids
Delay of Gastric emptying affect some drugs especially_____
Acid
Base
Neutral
All above
Absorption of griseofulvin increased when
Taken in capsule form
Taking it with food
Taking it with lemon juice
Taking it with empty stomach
Drug-drug interactions reduce the absorption of drugs
True
False
Sublingual and Buccal absorption are unlimited
True
False
Absorption for inhalation route is good because of its large surface area.
True
False
For subcutaneous absorption, lipophilic drug diffuse directly through pores while water soluble drugs diffuse directly through capillary membrane
True
False
-Absorption from muscle to systemic circulation depends on muscle blood flow
-Absorbed faster from deltoid than gluteal muscle
True
False
Drug absorb in upper part of rectum still subjected to hepatic metabolism
True
False
What is the rate limiting barrier in transdermal absorption process
(a)
Which of the following delays the drug absorption from GIT?
Increased in peristalsis
Decreased in ionisation of drugs
Decreased gastric emptying
Increased in drug dissolution
