QUESTION WITH ANSWERS 2025/2026
Describe the effects of drugs based on the route of administration. - Absorption has a
many steps drug must be introduced via some route in order to be absorbed then
distributed.
Describe the role of the isoenzymes. - CYPs are the major enzymes in drug
metabolism. Must drugs undergo deactivation by CYPs are directly facilitated secretion
from the body. Many substances are bioactivated by CYPs to form their active
compound. Many drugs increase or decrease the activity of CYPs isoenzymes either by
inducing biosynthesis of an isozyme, which is enzyme induction or by directly inhibiting
the activity of CYP which is enzyme inhibition. This is a major source of adverse drug
reactions since changes in CYPs activity may affect the metabolism and clearance of
certain drugs. When two drugs are both metabolized by the CYP450 system the drugs
should be administered at separate times to prevent toxic effects.
According to the WHO, what is the first step in the prescribing process? - The first step
is defined the patient's problem to generate a clear indication for treatment. A summary
of the diagnostic part of the consultation signs symptoms diagnosis and relevant patient
characteristics like comorbidities, comedication pregnancy and drug allergies. This step
is the basis for choosing and prescribing the correct treatment during the next steps.
Second step is specific objectives with measurable parameters. Third step is to choose
drug needed first part of this step is the p drug (preferred drug selection and part two is
confirmation of drug. Step four is begin treating with p drug patient education is step five
step six involves evaluating p drug (continue adjust or stop).
What does the FDA have the authority to approve? - FDA is responsible for protecting
and promoting public health through the regulation and supervision of food safety,
tobacco products, prescription and over the counter drugs, biopharmaceutical, vaccines,
blood transfusions medical devices cosmetics animal foods and feed and vet products.
Post marketing surveillance is how the FDA monitors drug safety. It also determines all
of the labeling for all prescription and over the counter meds. FDA does not regulate
herbal supplements.
What is off label prescribing? - Off label use is the prescription of drugs for un approved
indication or age group dosage of route of administration. Both prescription and otc
drugs can be used in off label ways. However, most studies focus on prescription drugs.
Off label use is legal unless it violates ethical or safety guidelines. There can be health
risks or differences in legal liability.
What factors place an infant and child at risk when prescribing medications? - In
general, there is a lack of safety studies related to medications and the pediatric
population. Adverse drug reactions are most common in this age group. Children are
not just small adults they metabolize drugs differently than adults.
, What adverse drug reactions (ADRs) are the elderly at risk of developing? -
Physiological changes in elderly adults affect mainly how medications are metabolized
by the kidney and liver. Hepatic blood flow nearly decreases by 1/2 or 40 % in older
adults, and some degree of chronic kidney disease is present in nearly ½ of older
adults. The median renal blood flow decreases by ½ by the time the patient is 80 years
old. Although individual rates vary and 1/3 of older adults maintain normal renal
function. Heart failure affects more than 40% of persons older than 80 years. This
further reduces the function of aging kidneys and liver. Aging decreases first pass
clearance in the liver and a number of common drugs like warfarin, benzodiazepines,
and opiates require much lower diseases in older adults. Distribution of drugs to body
compartments is changed by the decrease in the ratio of lean body weight to body fat.
Levels of serum proteins which bind to many drugs decrease in older adults because of
malnutrition and dietary changes that are common for both intentional and unintentional
reasons. Drug metabolism can be affected by drug abuse like alcohol. Up to 10 % of
older adults are heavy or problem drinkers.
What are the ADRS related to special populations? - These can be related to genetics,
age, gender, drug interactions, and medical conditions.
Type 1 hypersensitivity - immediate is a reaction provoked by reexposure to a specific
type of antigen or allergen. Symptoms include mild irritation to anaphylactic shock.
Cytotoxic hypersensitivity the antibodies produce an immune response that binds to
antigens (allergens) at the surface of the cell. Antigens can be either intrinsic (apart of
the body)or extrinsic (outside of the body). ABO blood incompatibility where the blood
cells have a different antigen on them. B cell proliferation will take place, and antibodies
to foreign blood types are produced. IgG and IgM bind to these antigens to form
complexes that activate the pathway of the complement activation to eliminate cells
presenting as foreign antigens. That is mediators of acute inflammation are generated
at the site and membranes attack cause cell lysis and death. This reaction takes hours
to a day. - Type 2 hypersensitivity
accumulation of immune complexes or antigen-antibody complexes that may not have
been adequately cleared by innate immune cells giving rise to an inflammatory
response and attraction of leukocytes. Such reactions that progress to disease
produces immune complex diseases. The reaction can take hours, days, or weeks
depending on whether or not there is an immunologic memory of the precipitating
antigen. Typically clinical features begin a week following the initial antigen challenge
causing the immune complexes to cause an inflammatory response. - Type 3
hypersensitivity
delayed this reaction takes 2-3 days to begin. Unlike other types of reaction, it is not
antibody meditated but a cell-mediated response. - Type 4 hypersensitivity
Which medications interact with St. John's Wort? - A medicinal herb with antidepressant
effects and potent anti-inflammatory properties. St Johns wort interacts with SSRIs,