Pharmacology problems

2. 1. A patient was given Lignocaine with Adrenaline as local
anesthetic for a surgical procedure of tip of finger later
he developed severe pain and discoloration of finger
with appearance of gangrene.
a. What was the type of anesthesia called?
Ans: Type of anesthesia is called Ring infiltration anesthesia.
b. What was the reason behind the development of
symptoms?
Ans: The cause of this condition is due to local tissue necrosis
and ischemia leading to gangrene. Local anesthetics have
low tissue toxicity. But addition of a vasoconstrictor like
adrenaline enhances the local tissue damage. As a result
there is local tissue necrosis & gangrene.

3. c. Which precaution to be taken?
Ans: Vasoconstrictors should not be added for ring block
anesthesia in organs supplied by end arteries like fingers
for hands and toes, penis, nose and pinna because of no
collateral circulation.
d. List four advantages of combining Lignocaine with
adrenaline.
Ans: a) Prolongs duration of action of L.A. by decreasing
then rate of removal from local site into circulation.
b) Enhances intensity of new block.
c) Provides more bloodless field of surgery.
d) Reduces systemic toxicity of local anesthetics, as rate of
absorption is reduced & metabolism keeps the plasma
concentration lower.

4. 2. Mr. Krishna Rao a psychiatric patient was on large dose
of haloperidol 20mg tablets for four weeks. He
developed rigidity tremor, mask like face with shuffling
gait and bradykinesia.
a. What is the condition called?
Ans: The condition is called Parkinsonism.
b. What is the cause?
Ans: It is due to disturbance in the dopamine acetyl choline
balance in the basal ganglia because of D₂ receptor blocked.
c. What drugs are given to correct these side effects?
Ans: Restoration of cholinergic dopaminergic balance with
centrally acting anticholinergic drugs- Procyclidine, Benz
tropine, Orphenadrine.

5. 3. 38years kavitha who is a vaishya was posted for
abdominal surgery. The anesthetist injected succinyl
choline prior to intubation for skeletal muscle
relaxation. This patient had respiratory problem.
a. What adverse event occurred in this patient?
Ans: Succinyl choline induced apnea & respiratory paralysis.
b. How would you treat this condition?
Ans: Mechanical ventilation, monitoring the vitals, fresh
frozen plasma or whole blood transfusion for increasing
cholinesterase levels. Neostigmine can be given in phase-I
block but controversial since it has to be monitored. It is
contra indicated in Phase –II block.

6. c. What type of muscle relaxant is SCh?
Ans: Succinyl choline is a depolarizing blocker
d. What are other adverse effects of SCh?
Ans:
1. Respiratory paralysis & prolonged apnea.
2. Fall in BP & cardiovascular collapse
3. Cardiac arrhythmias & arrest in digitalized patient.
4. Precipitation of asthma.
5. Post operative muscle soreness.
6. Flushing is common.
7. Hyperkalemia
8. Malignant hyperthermia
9. Prolonged apnea.
10. Rise of intraoccular pressure.

7. e. Give 2 examples of drugs eliminated by
Hoffmann’s elimination.
Ans:
Atracurium
Cisatracurium

8. 4. A male patient while getting operated with a general
anaesthetic (halothane) and a skeletal muscle
relaxant (succinyl choline), developed a sudden rise of
body temperature to 105°F.
a. What is the condition known as?
Ans: The condition is known as malignant hyperthermia.
b. What is the cause of this condition?
Ans: The cause is due to an abnormal (RYR) ryanodine
receptor of the Ca⁺² channel present at the sarcoplasmic
reticulum of the skeletal muscles, which is triggered by
halothane to release massive amount of Ca⁺² intracellularly
causing persistent muscle contraction and increased heat
production. Succinyl choline accentuates the condition.

9. c. How will you treat the condition?
Ans: Treatment is rapid external cooling; infusion of
sodium bicarbonate, 100% O₂ inhalation and
administration of I.V dantrolene 1mg/kg body weight.
d. How does it act?
Ans: Dantrolene acts on Ryanodine receptor of Ca⁺²
channels in the sarcoplasmic reticulum of skeletal
muscles and present their depolarization triggered
opening of Ca⁺² channels. So intracellular release of
Ca⁺² needed for excitation, contraction coupling is
interfered with.

10. 5. 55yrs Surya rao had small cell lung cancer, the
oncologist prescribed Cisplatin, Procarbazine,
Methotrexate in his chemotherapy regimen.
Following this he developed 8 episodes of vomiting
within 2 hours.
a. What is the cause of severe vomiting in the
patient?
Ans: Drug induced vomiting. This is due to direct
stimulation of chemo receptor trigger zone by the drug
as well as generation of emetic impulses or mediators
from the upper GIT.
b. What should have been done to prevent it?
Ans: 5-HT3 antagonist Ondansetron, Granisetron should
have been given to prevent vomiting.

11. c. What would you do to treat this patient?
Ans: 5-HT3 antagonists – like Ondansetron, Granisetron
should be given by slow IV (8mg) infusion over 15-30min
before chemotherapy followed by two similar doses 4 hours
apart.
d. What is the mechanism of action of this drug and
mention 2 other drugs belonging to the same group?
Ans: Ondansetron blocks the depolarizing action of 5 - HT
through 5 HT3 receptors on the vagal afferents in the GIT as
well as in Nucleus tractus solitaries & chemo receptor
trigger zone, ondancetron blockes emetogenic impulses
both at their peripheral origin & their central relay.
Other examples: Granisetron, tropisetron, palonosetron.

12. 6. An adult male patient suffering from amoebiasis is
advised a course of treatment with metronidazole.
During therapy he has attended a dinner party where
he took alcohol. Suddenly he experienced throbbing
headache, perspiration, confusion, blurred vision and
fainted.
a. What is the cause?
Ans: The cause was due to Disulfiram -like reaction to alcohol
occurring in some patients taking metronidazole. It is due to
inhibition of metabolism of alcohol like Disulfiram,
metronidazole also inhibits aldehyde dehydrogenase,
causing accumulation of acetaldehyde in blood-responsible
for above syndrome.
b. Could it have been prevented?
Ans: It could have been prevented by avoiding alcohol intake
during treatment and till 4days of completion of treatment.

13. c. What would you advise the patient whenever you
prescribe metronidazole?
Ans: Whenever metronidazole is prescribed the patient is
advised to abstain from alcohol.
d. How will you treat acute amoebic dysentry?
Ans:
Ofloxacin 200mg BD for 7days
IV fluids if hypotenstion, tachycardia or severe vomiting
Intubation if patient is in coma or severe altered mental
status.

14. 7. 26 yrs Savitha having one child has been using oral
contraception since 2 years. She has H/O seizures
since 6 months for which her physician prescribed
Phenytoin and seizures are under control. Now she
presented to you with pregnancy.
a. What is the reason for failure of contraception in
this case?
Ans: The reason for failure of contraception in this case is
because Phenytoin being an enzyme inducer increases
the metabolism of oral contraceptives.
b. Which drug would have been safer in this case?
Ans: Sodium valproate would have been a safer drug.

15. c. Mention other adverse effects of Phenytoin?
Ans: The other adverse effects of Phenytoin are – gingival
hyperplasia, coarsening of facial features, megaloblastic
anaemia hirsutism, used during pregnancy there is
increased risk of congenital malformations like cleft lip,
cleft palate and congenital heart disease. Arrythmias
vitamin K deficiency, Ataxia .
d. If this patient wants to continue pregnancy what
precautions would you advise her.
Ans: Lamotrigine and levetiracetam – newer anti epileptic
drugs can be prescribed as a precautionary measure

16. 8. 6years Charan is diagnosed with meningitis due to Niesseria
meningitides. You have prescribed him with Benzathine penicillin
1.2million units intramuscularly. Immediately the child developed
severe wheeze with difficulty to breath and bronchospasm. He had
rash all over his body and the peripheries became cool and
cyanosed. His heart rate is 150/min and temperature is 102ºF.
a. What is the cause of this condition?
Ans: Immediate hyper sensitivity reaction and anaphylaxis.
b. How would you treat it?
Ans:
1. Adrenaline(s.c or I.M) 0.5g (0.5ml of 1 in 1000solution i.m. repeat
every 5-10min)
2. Corticosteroids (I.V or I.M) – (glucocorticoids ) – hydrocortisone sod.
Succinate (100-200mg) IV.
3. Antihistamines (I.M) chlorpheniramine (10-20mg) i.m. or slow IV.
4. Supportive measures – O2 inhalation at high flow rate (100%) IV
fluids or plasma expandersand put the patient in reclining position.

17. c. What are the alternate drugs of choice which can
be used in meningitis?
Ans: Alternate drugs are
1. Cefotaxime (2gms I.V. 6th hourly) or
2. Ceftriaxone (2gms I.V. 12 hourly)
3. Ampicillin
4. Chloramphenicol
d. If you do not have an alternate drug how would
you treat the patient for meningitis?
Ans: If we do not have alternate drugs for meningococcal
meningitis we desensitize the patient for Benzathine
penicillin.

18. 9. Ashok aged 56yrs comes for a regular health
checkup his BP was 150/110mmHg and he was
advised to take Ramipril with Hydrochlorthiazide
and was asked to continue for 3weeks. When he
had another consultation, then his BP was
130/80mmHg.
a. Why was he administered this combination?
Ans: He was given this combination because they are the
first line drugs of choice for 30 – 60 yrs age group.
b. Why is this combination given for 3 weeks before
next consultation?
Ans: In 2-3 weeks time the steady state concentration in
plasma is achieved and the complete drug effects are
seen after 3weeks.

19. c. Why this combination is preferred?
Ans: This combination is preferred because Thiazides increase the
activity of renin – angiotensin system while ACE inhibitors block
it. This is because of different but complimentary mechanism of
action. Both require once daily dose, achieve maximum
hypotensive effect approximately 4hours after administration.
d. 6 adverse effects of ACE inhibitors.
Ans:
1. Ortho static Hypotension
2. Hyperkalaemia in patients with impaired renal function and
those taking K+ sparing diuretics.
3. Cough
4. Rashes
5. Angioedema – there is swelling of lips, mouth, nose, larynx
6. Fetopathic – fetal growth retardation, hypoplasia of organs and
fetal death.
7. Taste disturbances (dysguesia)

20. e. 10 adverse effects of Hydrochlorthiazide.
Ans:
1. Hypokalaemia manifests as weakness, fatigue, muscle cramps and cardiac
anhythmias. It can be prevented and treated by high dietary K+ intake or
supplements of kcl (24 – 72 mEg) per day or concurrnent used of K+ sparing
diuretics.
2. Acute saline depletion because isotonic saline is lost, serum Na+ and Cl-
levels remain normal.
Treated by saline infusion.
3. Dilutional hyponatraemia – managed by withholding diuretics, restrict
water intake and give glucocorticoid.
4. GIT and CNS disturbances –
Headache, giddiness, nausea, vomiting and diarrhoea, paraesthesia and
impotence.
5. Allergic manifestations – rashes photo sensitivity.
6. Hyperuricaemia
7. Hyperglycemia and hyperlipidemia
8. Hypercalcaemia
9. Magnesium depletion
10. Metabolic alkalosis

21. 10. Mr. Raju aged 70yrs was having Diabetes,
Hypertension and Congestive Cardiac Failure. He was
advised to take anti diabetic, antihypertensive drugs
and Verapamil to maintain chronically. In between Mr.
Raju happened to visit another physician for
tachycardia and without any drug history doctor
administered Metoprolol later on after 3 days patient
landed up in casuality and diagnosed as having heart
block.
a. Why did he suffer from heart block?
Ans: Because the patient is given β-blocker (Metoprolol) and a
calcium channel blocker (Verapamil) together.
b. M.O.A of both drugs.
Ans: Metoprolol β1selectien blocker.
Verapamil non dihydropyridine calcium channel blocker.

22. c. Why both should not be administrated together?
Ans: β-blockers like Metoprolol reduce heart rate,
myocardial contractility, conduction velocity and cardiac
output by their action on β1 receptors on heart.
CCB’s like Verapamil when given with β-blockers have
additive depressant action on SA node and AV conduction
and can lead to cardiac arrest and heart blocks. Therefore
the combination of β-blockers and CCB’s are CI and
especially never combined in old age.
d. How Digoxin is used in Atrial fibrillation?
Ans: Digoxin reduces conduction velocity and increases
effective refractory period (ERP) of AV node. A ventricular
rate of 72 – 80 beats/min should be achieved with it
(Therapeutic end point). If not, then add either β-blocker
or Verapamil but not both.