Review of Pharmacology - 9E (2015)

Review of Pharmacology
General Pharmacology
26
95. A 70 kg man was given a drug in a dose of 100 mg/kg
body weight. Its t 1/2
is 10 hours, initial plasma concentration
is 1.9 mg/ml. True statement is:
(a) CL is 0.02 litre/hr (PGI Dec. 2006)
(b) CL is 20 litre/hr
(c) k is 0.0693
(d) k is 6.93
(e) CL is 0.2 litre/hr
96. Amount of a drug X administered to a patient is 4.0 g
and its plasma concentration is found to be 50 mg/ml,
what will be the volume of distribution of drug X?
(a) 100L
(b) 80L
(c) 60L
(d) 50L
97. Maintenance dose rate of a drug depends primarily on:
(a) Volume of distribution
(b) Half life
(c) Lipid solubility
(d) Total body clearance
98. Rate of elimination of a new drug is 20 mg/hr at a
steady state plasma concentration of 10 mg/L, then its
renal clearance will be:
(a) 0.5 L/hr
(b) 2.0 L/hr
(c) 5.0 L/hr
(d) 20 L/hr
99. A drug following first order kinetics is being
administered by constant i.v. infusion at a rate of 10 mg/
min. Its steady state plasma concentration is 2 mg/min.
If the dose rate is increased to 20 mg/dl, what will be the
new steady state plasma concentration?
(a) 6 mg/dl
(b) 4 mg/dl
(c) 3 mg/dl
(d) 1 mg/dl
100. Ram Prashad is admitted to Guru Teg Bahadur
Hospital with respiratory infection for which antibiotic
tobramycin is ordered. The clearance and Vd of
tobramycin in him are 160 ml/min and 40 L, respectively.
If you wish to give Ram Prashad an intravenous loading
dose to achieve the therapeutic plasma concentration of
4 mg/L rapidly, how much should be given?
(a) 0.1 mg
(b) 10 mg
(c) 115.2 mg
(d) 160 mg
101. A 30 year old patient on digoxin therapy has developed
digitalis toxicity. The plasma digoxin level is 4 ng/
ml. Renal function is normal and the plasma t1/2 for
digoxin in this patient is 1.6 days. How long should you
withhold digoxin in order to reach a safer yet probably
therapeutic level of 1 ng/ml?
(a) 1.6 days
(b) 2.4 days
(c) 3.2 days
(d) 4.8 days
102. An old man enters the hospital with myocardial
infarction and a severe ventricular arrhythmia. The
antiarrhythmic drug chosen has a narrow therapeutic
window. The minimum toxic plasma concentration is 1.5
times the minimum therapeutic plasma concentration.
The half life is 6 hrs. It is essential to maintain the
plasma concentration above the minimum therapeutic
level to prevent a possible lethal arrhythmia. Of the
following, the most appropriate dosing regimen would
be:
(a) Once a day
(b) Twice a day
(c) Four times a day
(d) Constant intravenous infusion
103. A young male Kallu is brought to the hospital with
severe asthma. The pharmacokinetics of theophylline
include the following parameters: V d
= 35 L; CL = 48
ml/min; half life is 8 hrs. If an intravenous infusion of
theophylline is started at a rate of 0.48 mg/min, how
long will it take to reach 93.75% of the final steady state?
(a) Approximately 48 min
(b) Approximately 5.8 hrs
(c) Approximately 8 hrs
(d) Approximately 32 hrs
104. A patient requires an infusion of procainamide. Its half
life is 2 hrs. The infusion is begun at 9 AM At 1 PM on
the same day, the blood concentration is found to be
3 mg/L.What is the probable steady state concentration
after 2 days of infusion?
(a) 3 mg/L
(b) 4 mg/L
(c) 6 mg/L
(d) 15 mg/L
105. A volunteer Ram will receive a new drug in a phase
I clinical trial. The clearance and the volume of
distribution of the drug in Ram are 1.386 L/hr and 80 L
respectively. The half life of the drug in him would be
approximately:
(a) 83 hr
(b) 77 hr
(c) 40 hr
(d) 0.02 hr
106. Drug X is normally administered to patients at a rate of
50 mg/hour. Elimination of the drug X from body takes
place as:
- Hepatic Metabolism 10%
- Biliary Secretion 10%
- Renal Excretion 80%
This drug has to be administered to a 65 years old patient
Uttaam Singh, with a GFR of 60 ml/min. (assuming
normal GFR is 120ml/min). Liver and biliary functions
are normal in this patient. What should be the dose rate
of drug X in this patient?
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