NR 293 PHARMACOLOGY CORE REVIEW EXAMS
QUESTIONS AND ANSWERS SURE A+
✔✔What is the mode of action for coumarins? - ✔✔-Inhibits vitamin K synthesis by
bacteria in the gastrointestinal tract
-Inhibits production of vitamin K-dependent clotting factors II, VII, IX, and X, which are
normally synthesized in the liver
Final effect prevention of clot formation
✔✔What are indications for anticoagulants? - ✔✔Used to prevent clot formation in
certain settings in which clot formation is likely
MI
Unstable angina
Atrial fibrillation
Indwelling devices, such as mechanical heart valves
Major orthopedic surgery
Prolongued immobilization
Prevent and treat clots
✔✔What are contraindications for anticoagulants? - ✔✔Drug allergy
Any acute bleeding process or high risk for such an occurrence
Warfarin is strongly contraindicated in pregnancy.
Other anticoagulants are rated in lower pregnancy categories (B or C).
LMWHs are contraindicated in patients with an indwelling epidural catheter risk of
epidural hematoma.
✔✔What are adverse effects of anticoagulants? - ✔✔Bleeding
,-Risk increases with increased dosages
-May be localized or systemic
Heparin-induced thrombocytopenia
Type 1 - gradual reduction in platelet - heparin continued
Type 2 - Acute Fall in patient's platelets usually 50% - discontinue heparin
- Paradoxical risk of thrombosis and can be fatal. 5-15%
✔✔What is the treatment for heparin-induced thrombocytopenia? - ✔✔Treatment for
HIT is lepirudin and argatroban
✔✔compare type1 and type 2 thrombocytopenia - ✔✔Type I
-Gradual reduction in platelets
-Heparin therapy can generally be continued.
Type II
-Acute fall in the number of platelets (more than 50% reduction from baseline)
-Discontinue heparin.
✔✔What can warfarin do with a patient with thrombocytopenia? - ✔✔Use of warfarin:
can cause skin necrosis and "purple toes" syndrome
✔✔What are the toxic effects of heparin? - ✔✔Symptoms: hematuria, melena (blood in
the stool), petechiae, ecchymoses, and gum or mucous membrane bleeding
✔✔What is the treatment for heparin toxicity? - ✔✔Stop drug immediately: heparin has
a short half life
Intravenous (IV) protamine sulfate: 1 mg of protamine can reverse the effects of 100
units of heparin.
-Works less than 5 minutes
-1 g doses heparin -> 1g volume blood loss -> packed red blood cells
✔✔What is the treatment for warfarin overdose? - ✔✔- Discontinue the warfarin.
- May take 36 to 42 hours before the liver can resynthesize enough clotting factors to
reverse the warfarin effects
- Vitamin K1 (phytonadione) can hasten the return to normal coagulation.
- High doses of vitamin K (10 mg) given IV will reverse the anticoagulation within 6
hours.
✔✔What are adverse side effects of warfarin? - ✔✔bleeding, lethargy, muscle pain,
purple toes
✔✔What are drug interactions with anticoagulants? - ✔✔drugs that Increase
anticoagulation activity:
,-enzymes inhibitors of metabolism
-displacement of the drug from inactive protein binding sites
- decrease Vit K absorption and synthesis by bacterial flora
-alter platelet count or activity
ASA + warfarin + heparin -> increase risk for bleeding
Patient on IV heparin :
- recommended to start warfarin at the same time
- Overlap the therapy by 5 days
- Stop the heparin after 5 days only after INR is above 2
✔✔Why do we dont do hep-locks any more? - ✔✔No more hep-lock because of risk for
Heparin Induced Thrombocytopenia
✔✔what is the prophylaxis administration of heparin for DVT? - ✔✔DVT prophylaxis:
5000 units subcutaneously two or three times a day; does not need to be monitored
when used for prophylaxis
✔✔what is the therapeutic admistration instructions for heparin? - ✔✔When heparin is
used therapeutically (for treatment), continuous IV infusion. Weight based dose
- Measurement of aPTT (usually every 6 hours until therapeutic effects are seen) is
necessary.
✔✔A patient is receiving an IV infusion of heparin and was started on warfarin therapy
the night before. Which statement is most correct?
a. The patient is receiving a double dose of anticoagulants.
b. The heparin therapy was ineffective, so the warfarin was started.
c. The heparin provides anticoagulation until therapeutic levels of warfarin are reached.
d. The heparin and warfarin work together synergistically to provide anticoagulation. -
✔✔Correct answer: C
Rationale: Heparin has a faster onset and therefore is used to provide anticoagulation
until therapeutic levels of warfarin are reached.
✔✔What are anti-histamines? - ✔✔Drugs that directly compete with histamine for
specific receptor sites
Two histamine receptors
H1 (histamine 1)
H2 (histamine 2)
✔✔what are the mechanism of antihistamine? - ✔✔Block action of histamine at H1
receptor sites
, Compete with histamine for binding at unoccupied receptors
Cannot push histamine off the receptor if already bound
The binding of H1 blockers to the histamine receptors prevents the adverse
consequences of histamine stimulation
-Vasodilation
-Increased gastrointestinal (GI) and respiratory secretions
-Increased capillary permeability
✔✔Antihistamine effects - ✔✔Reduce dilation of blood vessels
Reduce increased permeability of blood vessels
reduce salivary, gastric, lacrimal, and bronchial secretions
: bind to histamine receptors, thus preventing histamine from causing a response
✔✔What are indications of antihistamines? - ✔✔Nasal allergies
Seasonal or perennial allergic rhinitis (hay fever)
Allergic reactions
Motion sickness
Parkinson's disease
Sleep disorders
Also used to relieve symptoms associated with the common cold
- Sneezing, runny nose
-Palliative treatment; not curative
✔✔what are contraindications of antihistamines? - ✔✔Known drug allergy
Narrow-angle glaucoma
Cardiac disease, hypertension
Kidney disease
Bronchial asthma, chronic obstructive pulmonary disease (COPD)
Sole drug therapy during acute asthmatic attacks
- Albuterol or epinephrine
Peptic ulcer disease
Seizure disorders
Benign prostatic hyperplasia (BPH)
Pregnancy
✔✔What are adverse effects of antihistamines? - ✔✔Anticholinergic (drying) effects:
most common
-Dry mouth
-Difficulty urinating
-Constipation
-Changes in vision
Drowsiness
-Mild drowsiness to deep sleep
QUESTIONS AND ANSWERS SURE A+
✔✔What is the mode of action for coumarins? - ✔✔-Inhibits vitamin K synthesis by
bacteria in the gastrointestinal tract
-Inhibits production of vitamin K-dependent clotting factors II, VII, IX, and X, which are
normally synthesized in the liver
Final effect prevention of clot formation
✔✔What are indications for anticoagulants? - ✔✔Used to prevent clot formation in
certain settings in which clot formation is likely
MI
Unstable angina
Atrial fibrillation
Indwelling devices, such as mechanical heart valves
Major orthopedic surgery
Prolongued immobilization
Prevent and treat clots
✔✔What are contraindications for anticoagulants? - ✔✔Drug allergy
Any acute bleeding process or high risk for such an occurrence
Warfarin is strongly contraindicated in pregnancy.
Other anticoagulants are rated in lower pregnancy categories (B or C).
LMWHs are contraindicated in patients with an indwelling epidural catheter risk of
epidural hematoma.
✔✔What are adverse effects of anticoagulants? - ✔✔Bleeding
,-Risk increases with increased dosages
-May be localized or systemic
Heparin-induced thrombocytopenia
Type 1 - gradual reduction in platelet - heparin continued
Type 2 - Acute Fall in patient's platelets usually 50% - discontinue heparin
- Paradoxical risk of thrombosis and can be fatal. 5-15%
✔✔What is the treatment for heparin-induced thrombocytopenia? - ✔✔Treatment for
HIT is lepirudin and argatroban
✔✔compare type1 and type 2 thrombocytopenia - ✔✔Type I
-Gradual reduction in platelets
-Heparin therapy can generally be continued.
Type II
-Acute fall in the number of platelets (more than 50% reduction from baseline)
-Discontinue heparin.
✔✔What can warfarin do with a patient with thrombocytopenia? - ✔✔Use of warfarin:
can cause skin necrosis and "purple toes" syndrome
✔✔What are the toxic effects of heparin? - ✔✔Symptoms: hematuria, melena (blood in
the stool), petechiae, ecchymoses, and gum or mucous membrane bleeding
✔✔What is the treatment for heparin toxicity? - ✔✔Stop drug immediately: heparin has
a short half life
Intravenous (IV) protamine sulfate: 1 mg of protamine can reverse the effects of 100
units of heparin.
-Works less than 5 minutes
-1 g doses heparin -> 1g volume blood loss -> packed red blood cells
✔✔What is the treatment for warfarin overdose? - ✔✔- Discontinue the warfarin.
- May take 36 to 42 hours before the liver can resynthesize enough clotting factors to
reverse the warfarin effects
- Vitamin K1 (phytonadione) can hasten the return to normal coagulation.
- High doses of vitamin K (10 mg) given IV will reverse the anticoagulation within 6
hours.
✔✔What are adverse side effects of warfarin? - ✔✔bleeding, lethargy, muscle pain,
purple toes
✔✔What are drug interactions with anticoagulants? - ✔✔drugs that Increase
anticoagulation activity:
,-enzymes inhibitors of metabolism
-displacement of the drug from inactive protein binding sites
- decrease Vit K absorption and synthesis by bacterial flora
-alter platelet count or activity
ASA + warfarin + heparin -> increase risk for bleeding
Patient on IV heparin :
- recommended to start warfarin at the same time
- Overlap the therapy by 5 days
- Stop the heparin after 5 days only after INR is above 2
✔✔Why do we dont do hep-locks any more? - ✔✔No more hep-lock because of risk for
Heparin Induced Thrombocytopenia
✔✔what is the prophylaxis administration of heparin for DVT? - ✔✔DVT prophylaxis:
5000 units subcutaneously two or three times a day; does not need to be monitored
when used for prophylaxis
✔✔what is the therapeutic admistration instructions for heparin? - ✔✔When heparin is
used therapeutically (for treatment), continuous IV infusion. Weight based dose
- Measurement of aPTT (usually every 6 hours until therapeutic effects are seen) is
necessary.
✔✔A patient is receiving an IV infusion of heparin and was started on warfarin therapy
the night before. Which statement is most correct?
a. The patient is receiving a double dose of anticoagulants.
b. The heparin therapy was ineffective, so the warfarin was started.
c. The heparin provides anticoagulation until therapeutic levels of warfarin are reached.
d. The heparin and warfarin work together synergistically to provide anticoagulation. -
✔✔Correct answer: C
Rationale: Heparin has a faster onset and therefore is used to provide anticoagulation
until therapeutic levels of warfarin are reached.
✔✔What are anti-histamines? - ✔✔Drugs that directly compete with histamine for
specific receptor sites
Two histamine receptors
H1 (histamine 1)
H2 (histamine 2)
✔✔what are the mechanism of antihistamine? - ✔✔Block action of histamine at H1
receptor sites
, Compete with histamine for binding at unoccupied receptors
Cannot push histamine off the receptor if already bound
The binding of H1 blockers to the histamine receptors prevents the adverse
consequences of histamine stimulation
-Vasodilation
-Increased gastrointestinal (GI) and respiratory secretions
-Increased capillary permeability
✔✔Antihistamine effects - ✔✔Reduce dilation of blood vessels
Reduce increased permeability of blood vessels
reduce salivary, gastric, lacrimal, and bronchial secretions
: bind to histamine receptors, thus preventing histamine from causing a response
✔✔What are indications of antihistamines? - ✔✔Nasal allergies
Seasonal or perennial allergic rhinitis (hay fever)
Allergic reactions
Motion sickness
Parkinson's disease
Sleep disorders
Also used to relieve symptoms associated with the common cold
- Sneezing, runny nose
-Palliative treatment; not curative
✔✔what are contraindications of antihistamines? - ✔✔Known drug allergy
Narrow-angle glaucoma
Cardiac disease, hypertension
Kidney disease
Bronchial asthma, chronic obstructive pulmonary disease (COPD)
Sole drug therapy during acute asthmatic attacks
- Albuterol or epinephrine
Peptic ulcer disease
Seizure disorders
Benign prostatic hyperplasia (BPH)
Pregnancy
✔✔What are adverse effects of antihistamines? - ✔✔Anticholinergic (drying) effects:
most common
-Dry mouth
-Difficulty urinating
-Constipation
-Changes in vision
Drowsiness
-Mild drowsiness to deep sleep
