Pharmacology for Stroke

Question 1

Drug example of beta-blocker for stroke

Answer 1

Labetalol (Trandate)

Question 2

Labetalol (Trandate) MOA

Answer 2

Blocks stimulation of beta 1 and beta 2 adrenergic receptor sites. Also has blocking effect on alpha 1 receptor sites.

Question 3

Indication for Labetalol (Trandate)

Answer 3

Management of hypertension

Question 4

Therapeutic effect of labetalol (Trandate)

Answer 4

Decreased blood pressure

Question 5

Adverse effects of labetalol (Trandate)

Answer 5

Fatigue, weakness
Bronchospasm
Arrhythmias, bradycardia
Congestive heart failure, pulmonary edema
Orthostatic hypotension

Question 6

Precautions for labetalol (Trandate)

Answer 6

Allergies/ hypersensitivity
Heart failure
Pulmonary edema and pre-existing obstructive lung diseases
Bradycardia and heart blocks
Use cautiously in renal and liver dysfunction

Question 7

Nursing considerations for labetalol (Trandate)

Answer 7

Administer with meals to increase absorption
Frequent monitoring of BP and pulse
Take apical pulse prior to admin, if <50bpm, hold and notify physician
Assess for orthostatic hypotension
Monitor intake/ output
Daily weights
Assess for signs of fluid overload (lung crackles, weight gain, edema, fatigue)

Question 8

When receiving intravenous labetalol…

Answer 8

High alert medication → can be very dangerous
Patient must lay supine for 3 hours after admin
Vitals assessed q5-15 minutes during and after admin

Question 9

Stroke specific info: labetalol

Answer 9

Commonly used in acute phase of stroke
Blood pressure usually rises following a stroke → thought to be a protective response to maintain cerebral perfusion
We only administer BP meds in ischemic stroke if the BP is extremely high

Question 10

In order to administer thrombolytic therapy

Answer 10

Systolic BP must be less than 185 mmHg and diastolic BP must be less than 110 mmHg

Question 11

If patient is not receiving thrombolytics for an ischemic stroke, then patient only requires antihypertensive if…

Answer 11

Systolic BP > 220 mmHg and diastolic > 120 mmHg

Question 12

For hemorrhagic stroke, administer antihypertensive if…

Answer 12

Systolic > 160 mmHg

Question 13

Patient education for labetalol (Trandate)

Answer 13

Abrupt withdrawal of labetalol can cause life threatening arrhythmias, hypertension, or myocardial infarction
Direct patient to make slow position changes → special caution when exercising, drinking alcohol, and in hot weather
Diabetic patients should have sugars monitored more closely → medication will mask warning signs of hypoglycemia (such as tachycardia)

Question 14

What is cyclooxygenase?

Answer 14

Cyclooxygenase is an enzyme found in all tissues. It converts arachidonic acid into prostaglandins and other related compounds like thromboxane A2, also called TXA 2

Question 15

What is COX 1?

Answer 15

COX 1 is found in almost all tissues and it is considered the “good cox”. It is like the housekeeper that protects many parts of the body.

Question 16

How does COX 1 work?

Answer 16

It works in the stomach and protects the gastric mucosa by reducing gastric acid secretion and maintaining blood flow. It supports the kidneys by supporting renal blood flow. It promotes platelet aggregation by synthesizing thromboxane A2.

Question 17

What is COX 2?

Answer 17

COX 2 comes into action during tissue injury. It mediates inflammation and sensitizes pain receptors. It also affects the brain where it facilitates fever and contributes to pain reception. It improves renal flow and dilate our blood vessels

Question 18

What is the name for aspirin?

Answer 18

Acetylsalicylic acid

Question 19

Acetylsalicylic acid MOA

Answer 19

Suppresses platelet aggregation by causing irreversible inhibition of cyclooxygenase

Question 20

Indications for acetylsalicylic acid

Answer 20

Inflammatory disorders
Fever
Prophylaxis for myocardial infarction and stroke
Non-opioid analgesic

Question 21

Therapeutic effect of acetylsalicylic acid

Answer 21

Decreased pain
Decreased inflammation
Decreased incidence of stroke and MI

Question 22

Adverse effects of acetylsalicylic acid

Answer 22

Heart burn, nausea → take with food or full glass of water
GI bleeds → may cause anemia with chronic occult blood loss
Gastric ulceration, perforation, bleeding, hemorrhage → prophylaxis with a PPI is recommended
Bleeding → discontinue 1-2 weeks prior to surgical procedures
Renal impairment → acute, reversible impairment in renal function
Salicylism → syndrome resulting from high levels of aspirin

Question 23

Precautions of acetylsalicylic acid

Answer 23

Allergies/ hypersensitivity/ asthma
Bleeding disorders or thrombocytopenia
Use cautiously in renal dysfunction, chronic alcohol abuse, history of GI bleeds or ulcer disease, liver disease

Question 24

Nursing considerations for acetylsalicylic acid

Answer 24

Monitor for signs and symptoms of bleeding → hypotension, tachycardia, dizziness, weakness, pallor, bruising, bleeding gums, epitaxis, hematuria, melena, labs (CBC)
After procedures and injections → apply pressure to site to prevent bleeding and monitor the site carefully
Take aspirin with food or glass of water
Discontinue at least one week prior to surgery
Monitor renal function → weigh patient, urea and creatinine levels, urine output

Question 25

Aspirin - prevention of stroke

Answer 25

Thromboxane A2 → stimulates activation of new platelets and increases platelet aggregation Often stroke result from platelet aggregation at site of endothelial damage Aspirin prevents platelet adhesion and aggregation → inhibits the formation of thromboxane A2 by platelets

Question 26

Dose of aspirin for prevention of cardiovascular disease

Answer 26

81mg per day

Question 27

Treatment of aspirin after ischemic stroke

Answer 27

Initiate within 48 hours of stroke onset

Question 28

Most common sites for bleeding

Answer 28

Recent wounds Sites of needle puncture Sites of invasive procedures/ surgery

Question 29

Exemplar of thrombolytic

Answer 29

Tissue plasminogen activator (Alteplase)

Question 30

Tissue Plasminogen Activator (Alteplase) MOA

Answer 30

Binds to fibrin in a blood clot and activates plasminogen, forming plasmin (fibrinolytic enzyme) which breaks down and dissolves the clot

Question 31

Indications for Tissue Plasminogen Activator (Alteplase)

Answer 31

Acute MI Ischemic stroke Pulmonary embolus

Question 32

Therapeutic effect of Tissue Plasminogen Activator (Alteplase)

Answer 32

Break down clot and restore blood flow through the vessel

Question 33

Adverse effects for Tissue Plasminogen Activator (Alteplase)

Answer 33

There are two main reasons for bleeding: 1. Plasmin destroys preexisting clots and can promote bleeding at sites that have recently healed 2. Degradation of clotting factors which disrupts the ability for the body to coagulate when trauma or injury does occur

Question 34

Nursing considerations for Tissue Plasminogen Activator (Alteplase)

Answer 34

Patients are screened carefully admin - ischemic stroke must be confirmed on CT scan Must be administered within 3-4.5 hrs of symptoms onset - "door to needle" < 60 min Patient history taken to determine contraindications Baseline coagulation blood work sent (INR, aPTT, platelets, hgb) Frequent monitoring of vital signs and EKG monitoring Glasgow Coma Scale and neurochecks - high risk for intracranial bleeding Monitor for bleeding - major risk Hold all anticoagulants and antiplatelets for 24hr To reduce risk of bleeding → avoid subcut and IM injections, minimize invasive procedures, do not administer with anticoagulants, do not administer with antiplatelets

Question 35

Absolute contraindications for Tissue Plasminogen Activator (Alteplase)

Answer 35

Previous intracranial bleeding Known intracranial lesions/ tumours Active internal bleeding (with the exception of menses) Suspected aortic dissection

Question 36

Relative contraindications for Tissue Plasminogen Activator (Alteplase)

Answer 36

Severe uncontrolled hypertension >180/110 mmHg Current anticoagulant use Traumatic/ prolonged CPR/ surgery <3 weeks ago Recent internal bleeding (within 2-4 weeks) Pregnancy Active peptic ulcer

Question 37

TPA and stroke

Answer 37

Only use for ischemic stroke - must be confirmed with CT scan Must be administered within 4.5 hours of symptom onset Administered to reestablish blood flow through a blocked artery Increases risk of intracranial hemorrhage

Question 38

Drug example of an anticoagulant

Answer 38

Unfractionated heparin

Question 39

Unfractionated heparin MOA

Answer 39

Enhance activity of antithrombin which is a protein that inactivates clotting factors (thrombin and factor Xa). Without these two clotting factors, there is reduced production of fibrin and clotting is suppressed

Question 40

Indications for unfractionated heparin

Answer 40

Pulmonary embolism Deep vein thrombosis Dialysis and open-heart surgery Post-operative, spinal cord injury, stroke DVT prophylaxis → to be initiated within 48-72 hrs of ischemic stroke Acute myocardial infarction

Question 41

Therapeutic effect of unfractionated heparin

Answer 41

Prevention of new clots

Question 42

Adverse effects of unfractionated heparin

Answer 42

Bleeding/ hemorrhage → develops in about 10% of patients Epidural hematoma → can develop in patients with epidural/ spinal anaesthesia Heparin Induced Thrombocytopenia (HIT) → immune mediated disorder causing reduced platelet count and increase in thrombotic events. Antibodies develop against heparin-platelet complexes Antidote → Protamine Sulfate

Question 43

Nursing considerations for unfractionated heparin

Answer 43

Monitor vital signs Labs → monitor aPTT (activated partial thromboplastin time), should be checked every 4-6 hrs when on a heparin infusion, monitor platelets and hgb Monitor for signs and symptoms of bleeding → pallor, bruising, bleeding gums, epistaxis, melon, hematuria Monitor hands and feet for colour, warmth, circulation, movement → signs of clots from heparin induced thrombocytopenia

Question 44

Drug example of HMG-CoA reductase inhibitor "statins"

Answer 44

Atorvastatin (Lipitor)

Question 45

HMG-CoA reductase inhibitor "statins" MOA

Answer 45

Lower the rate of cholesterol production HMG-CoA reductase synthesizes cholesterol → statins block the enzyme which decreases cholesterol production Liver increases LDL receptors and hepatocytes remove LDL from blood

Question 46

Indications for HMG-CoA reductase inhibitor "statins"

Answer 46

Hypercholesterolemia Risk reduction for stroke, myocardial infarction, and angina Diabetes

Question 47

Therapeutic effect of HMG-CoA reductase inhibitor "statins"

Answer 47

Lower LDL cholesterol Elevate HDL cholesterol Reduce triglycerides

Question 48

Nursing considerations for HMG-CoA reductase inhibitor "statins"

Answer 48

Check serum lipid levels and triglycerides Should assess liver function (LFTs) Administer in evening

Question 49

Additional info for HMG-CoA reductase inhibitor "statins"

Answer 49

Well tolerated overall, minimal side effects Teratogenic Should not have grapefruit juice