This tutorial provides information on various principles of pharmacology. It discusses different routes of drug administration including enteral, intramuscular, intrathecal, intravenous, and transdermal. It also covers pharmacokinetic processes such as absorption, distribution, metabolism, and elimination. The tutorial presents several clinical cases and questions related to selecting the appropriate route of administration based on patient factors and ensuring optimal drug concentrations.

1. TUTORIAL ON GENERAL
PRINCIPLES OF PHARMACOLOGY
DR VENKATA SUBBA REDDY A
PG IN PHARMACOLOGY
ANDHRA MEDICAL COLLEGE
VISAKHAPATNAM

3. A.Enteral
B. Intramuscular
C. Intrathecal
D.Intravenous
E. Transdermal
A 79-year-old man with end-stage Alzheimer’s disease and
dysphagia is taking multiple medications. Physical examination
reveals xerostomia and a limited gag reflex. Which of the following
routes of medication administration would provide the lowest serum
drug concentration?

4. Dysphagia and Alzheimer’s disease.
Would make drug administration by mouth difficult and limit direct absorption
via the stomach.
Give the lowest serum drug concentrations
(B) Intramuscular administration, although painful for the patient, would give
acceptable serum drug concentrations.
(C) Intrathecal administration would give acceptable therapeutic drug
concentrations but would be limited to CNS disease states.
(D) Intravenous administration would provide medications via vein and
therapeutic drug concentrations. It could be used for various medications.
(E) Transdermal administration applies medications to the skin and could
achieve therapeutic drug concentrations

5. A.Absorption
B. Distribution
C. Elimination
D.Glycosylation
E. Metabolism
A 28-year-old man with seborrheic dermatitis is prescribed a topical
corticosteroid crème by his dermatologist in hopes of alleviating the
chronic rash and erythema on the cheeks. Which of the following
steps is most critical to achieve a therapeutic drug concentration in
plasma?

6.  Drug absorption from the site of administration, in this case via the
topical route, allows the medication to enter into the skin and then into
the plasma. Following this step, the medication can distribute into
tissues and also be metabolized in tissues.
 (B) Distribution occurs following absorption of the drug from the site of
administration.
 (C) Elimination involves removal of the drug from the body via urine,
bile, or feces.
 (D) Glycosylation is not a step in the process of drug pharmacokinetics.
 (E) Metabolism of drugs occurs in the kidneys or liver after the drug has
achieved adequate levels in tissues.

7. A. Inhalation
B. Intranasal puff metered dose
C. Subcutaneous
D. Sublingual
E. Topical
A 31-year-old man is brought to the emergency department complaining of
dyspnea. He has a history of asthma and has had multiple asthma attacks
requiring intubation for airway maintenance. He is noncompliant with his
medications prescribed for this condition. Physical examination reveals a young
man in acute distress. His room air oxygen saturation is 87%. In addition to
administration of oxygen, immediate drug administration of albuterol should be
administered by which of the following routes?

8.  Inhalation provides rapid delivery of a drug across a large surface area of the
respiratory tract and is the route of administration of choice in a patient with
an airway disease such as asthma. Inhaled albuterol is commonly
administered in this manner.
 (B) Intranasal puff metered dose would only deliver a small amount of drug
to the patient and would not be recommended in this acutely ill patient.
 (C) Subcutaneous administration is a slow route of administration and is not
preferred in this acutely ill patient.
 (D) Sublingual, although allowing the medication to enter the circulation
would be less preferred than the inhalation route in this acutely ill patient.
 (E) Topical administration would only achieve a local effect of the drug and is
contraindicated in this acutely ill patient.

9. A 48-year-old-man with end-stage liver disease is hospitalized on
the intensive care unit. Review of his blood work reveals elevated
liver function tests to five times the normal rate. The patient is
receiving multiple intravenous medications. Which of the following
medications is likely to be therapeutic for this patient?
A. Epinephrine
B. Erythromycin
C. Nifedipine
D. Rifampin
E. Verapamil

10.  This patient has endstage liver disease. This ability to metabolize
medications through the cytochrome system of the liver is impaired. Drugs
that are metabolized in this fashion will not be properly broken down and
will accumulate to toxic levels. Epinephrine is not metabolized by the
cytochrome system and can be used with caution in this patient.
 (B) Erythromycin is an antibiotic metabolized by the hepatic cytochrome
system.
 (C) Nifedipine is an antihypertensive metabolized by the hepatic
cytochrome system.
 (D) Rifampin is used in the treatment of tuberculosis and is also
metabolized by the hepatic cytochrome system.
 (E) Verapamil is a calcium channel blocker and is also metabolized by the
hepatic cytochrome system.

11. A hospitalized patient with systemic candidiasis is receiving
intravenous antifungal medications. He also has hepatic and renal
insufficiency. Which of the following drug administration schemes
would allow for the most steady state amount of drug in the body over
a 2-week hospitalization period where medication administration will
be necessary ?
A.Continuous IV infusion
B. Once weekly IV injection
C. Single daily IV injection
D.Twice daily IV injection
E. Twice weekly IV injection

12.  Continuous IV infusion results in a less rapid influx of drug into the body
initially. However, within a short time, a steady state of drug level in the body
will be achieved. Although the drug level will achieve steady state, injection
of drugs several times daily will result in higher drug amounts initially after
dosing but will decrease according to half-life.
 (B) Once weekly IV injection will result in a peak and trough level of the drug
with initially high concentrations and will decrease to almost no drug in the
system.
 (C) Single daily IV injections result in lower amounts of drug in the body with
peaks and troughs.
 (D) Twice daily IV injections will result in the highest amounts of drug in the
body but will also have peaks and troughs.
 (E) Twice weekly IV injections will result in higher amounts of drug in the
body as compared with once weekly IV injections.

13. A 27-year-old man with HIV disease and hepatic insufficiency
presents to his primary care physician complaining of rectal pain and
bleeding with bowel movements. Physical examination reveals
several internal and external hemorrhoids. The patient would like to
avoid surgical therapy for this condition. Which of the following
routes of drug administration would be preferred in this patient?
A.Enteral
B. Intramuscular
C. Intravenous
D.Rectal
E. Transdermal

14.  This patient has hemorrhoids, and a topical route of administration of
medication is preferred. This route avoids the hepatic first pass effect so the
patient’s liver insufficiency would not likely be problematic with this route of
administration.
 (A) Enteral route administration will be unlikely to achieve an adequate
therapeutic response in a patient with hemorrhoids.
 (B) Intramuscular route administration is an ineffective therapy for rectal
diseases.
 (C) Intravenous administration is an ineffective therapy for rectal diseases
such as hemorrhoids.
 (E) Transdermal administration achieves systemic effects through systemic
absorption of medication. It is not effective for internal hemorrhoids.

15.  A drug that binds to a receptor and produces a biological response
that mimics the response to the endogenous ligand is known as
A.Agonist
B. Antagonist
C. Functional antagonist
D.Partial agonist
E. Partial antagonist

16.  The definition of an agonist is the biologic response produced by a drug
binding to its receptor. For example, the a-adrenergic agonist phenylephrine
when it binds to its receptor produces responses similar to the endogenous
ligand.
 (B) Antagonists are drugs that decrease the actions of another drug or the
endogenous ligand.
 (C) Functional antagonists may act at a separate receptor and oppose those
effects of the agonist.
 (D) Partial agonists have activities somewhere between the full agonist and
no agonistic activity.
 (E) Partial antagonists have activities somewhere between the full
antagonist and no antagonistic activity.

17. A 22-year-old woman who is afraid of running into her former
boyfriend actually meets him unexpectedly in a shopping mall. Her
fears are because their former relationship was marked by physical
and mental abuse. Memories of him are met with increased anxiety
and fear. Which of the following physiologic responses would this
woman be expected to exhibit at this time of seeing this man?
A.Bradycardia
B. Diarrhea
C. Hypertension
D.Sweating
E. Tracheal deviation

18.  This patient is exhibiting features of the “fight-or-flight” response, which is
triggered by sympathetic activation. The cardiac effects include increased
heart rate, contractility, and blood pressure. Skeletal muscle blood vessels
dilate while skin blood vessels vasoconstrict.
 (A) This patient will exhibit tachycardia.
 (B) This patient will exhibit increased gastrointestinal sphincter tone.
 (D) This patient will have vasoconstriction of the skin and mucous
membranes.
 (E) Tracheal dilation, not deviation occurs in the “fight-or-flight” response.

19. A 15-year-old boy who has diabetes and is insulin dependent is
brought to the emergency department after collapsing at a baseball
game. His blood sugar is 463 mg/dL by finger stick. Which of the
following routes of administration would be most efficacious for
medications to bring the blood sugar down?
A.Intramuscular
B. Intravenous
C. Oral
D.Subcutaneous
E. Sublingual

20.  Insulin (as most drugs) needs to enter the bloodstream for maximal effect; IV
infusion will result in the fastest and highest peak blood insulin concentration.
There are many formulations of insulin for intramuscular or subcutaneous
injection, but even the fastest have no effect until the insulin reaches the systemic
blood circulation. There is no way to make insulin absorption into the blood from
intramuscular or subcutaneous injection faster than injecting directly into the
blood. The same can be said for inhaled and sublingual insulin preparations.
 (A) Intramuscular insulin can be given in rapidly acting formulations, but even this
is not as fast as IV insulin.
 (C) Insulin given orally would be broken down and rendered ineffective by
peptidases in the gut.
 (D) Subcutaneous insulin can be given in rapidly acting formulations, but even this
is not as fast as IV insulin.
 (E) Insulin is not normally given sublingually, and sublingual absorption is slower
than IV infusion.

21. A researcher is studying the bioavailability of commonly used
antimuscarinics to treat irritable bowel syndrome. Medication A is
administered in a 100 mg daily dose orally and 60 mg of the drug is
absorbed from the gastrointestinal tract unchanged. Thus, the
bioavailability of Medication A is
A.50%
B. 60%
C. 70%
D.80%
E. 90%

22.  Medication A has a bioavailability of 60%.
 Bioavailability is the fraction of administered drug that reaches the systemic
circulation.
 In this example, if 100 mg of Medication A is administered orally, and 60 mg
of this drug is absorbed unchanged, the bioavailability is 0.6, or 60%.
 Determining bioavailability is important for calculating drug dosages for
various routes of administration other than the intravenous route.