Drugs for Ischaemic heart disease 2 Flashcards
explain what happen with Glyceryl trinitrate
Glyceryl trinitrate – rapidly inactivated by hepatic metabolism
The following question are based on Glyceryl trinitrate
RoA for organic nitrates:
Absorbed where:
Ineffective when:
DoA:
Explain the effects of volatility:
Which one is better
- Route of administration: sublingual – onset of action = few minutes
converted to di- and mononitrates - Absorbed through the skin – transdermal patch
- Ineffective if administered orally – first pass metabolism by the liver
- Duration of action: 30 minutes
- Due to volatility of the active ingredient, if tablets are opened, the
volatile substance evaporates - Spray is better, more stable.
organic nitrates that is longer acting, absorbed and metabolised more slowly
Isosorbide mononitrate:
RoA for Isosorbide mononitrate
oral
When to take Isosorbide mononitrate
take twice daily in the morning (8:00) and at lunch (14:00) to allow
for the nitrate free period (to avoid tolerance)
Least lipophilic cardio-selective β1 blocker – loses selectivity at high
doses
Atenolol
Pks for Atenolol
- Give once daily
- Excreted mainly unchanged in the urine – may accumulate in kidney
failure
Not affected by liver disease, or drugs inhibiting hepatic metabolism
or conditions affecting hepatic blood flow
Name that drug
Atenolol
Contra-indication for atenolol
Contraindicated in heart block, symptomatic heart failure (unless or
until signs are controlled), sinus bradycardia, cardiogenic shock
Caution for atenolol
- Cautions: renal failure, pregnancy
Drug interatcion for Atenolol
Drug interactions:
* Digoxin, verapamil, diltiazem additive depressant effects on the heart;
* Insulin / oral antidiabetics, increased risk of hyperglycaemia and masking of
hypoglycaemia (except sweating)
Adverse effects for Atenolol
Adverse effects: Decreased HDL, increased TGs and glucose utilization
impairment, bronchospasm (asthma, high doses)
Explain the ACS
Acute reduction in coronary blood flow most often due to a ruptured
atherosclerotic plaque and subsequent formation of an intracoronary
thrombus. The reduction in coronary blood flow produces myocardial
ischemia and, if left untreated, may lead to myocardial infarction (MI).
List the spectrums of ACS
3 marks
- Unstable angina (UA)
- Non-ST-segment elevation myocardial infarction (NSTEMI)
- ST-segment elevation myocardial infarction (STEMI),
Explain the unstable angina and also the additional characteristics
Unstable angina is a medical emergency and if untreated can progress
to NSTEMI. Presents as chest pain or discomfort like stable angina but
with the following additional characteristics:
* angina at rest or minimal effort
* angina occurring for the first time, particularly if it occurs at rest
* prolonged angina > 10 minutes, not relieved by sublingual nitrates
* the pattern of angina accelerates and gets worse
Explain the short term goal for ACS treatment
Short-term goals:
* Early restoration of blood flow to the infarct-related artery to prevent
infarct expansion (in the case of MI) or prevent complete occlusion and MI
(in UA);
* Prevention of death and other MI complications;
* Prevention of coronary artery re-occlusion
* Relief of ischemic chest discomfort.
Explain the long-term goals for ACS treatment
Long-term goals:
* Control of atherosclerosis risk factors,
* Prevention of additional MACE, including reinfarction, stroke, and HF
* Improvement in quality of life.
List the MONA(older acronym) for ACS acute supporative care
MONA (older acronym)
* Morphine
* Oxygen
* Nitroglycerin
* Aspirin
List the THROMBINS2 (newer acronym)
THROMBINS2 (newer acronym)
* Thienopyridine (clopidogrel)
* Heparin
* RAAS
* Oxygen
* Morphine
* B-blocker
* Intervention
* Nitroglycerin
* Statin/salicylate
List the Initial management of unstable ANGINA PECTORIS &
NSTEMI
Lots but say what you can remember
- Oxygen 40% via facemask, if saturation < 94% or if in distress.
- Aspirin, oral, 150 mg as a single dose (chewed or dissolved) as soon as
possible. - ADD
- Nitrates, short acting, e.g.: isosorbide dinitrate, sublingual, 5 mg
immediately as a single dose. - May be repeated at 5-minute intervals for 3 or 4 doses.
- ADD
- Morphine 10 mg diluted with 10 mL of water for injection or sodium
chloride 0.9%, slow IV (Doctor prescribed). - Start with 5 mg; thereafter slowly increase by 1 mg/minute up to 10 mg.
- Can be repeated after 4–6 hours if necessary, for pain relief.
- Beware of hypotension.
List the Initial management of unstable acute MI & STEMI
- Before transfer: cardiopulmonary resuscitation if necessary
- Oxygen 40% via facemask, if saturation < 94% or if in distress.
- Aspirin, oral, 150 mg as a single dose (chewed or dissolved) as soon as possible.
- AND
- Nitrates, short acting, e.g.: isosorbide dinitrate, sublingual, 5 mg immediately as a
single dose. - May be repeated at 5-minute intervals for 3 or 4 doses.
- AND
- Morphine 10 mg diluted with 10 mL of water for injection or sodium chloride 0.9%,
slow IV (Doctor prescribed). - Start with 5 mg; thereafter slowly increase by 1 mg/minute up to 10 mg.
- Can be repeated after 4–6 hours if necessary, for pain relief.
- Beware of hypotension.
- AND (if patient qualify)
- Thrombolytic: streptokinase OR if unavailable alteplase
List the indications for thrombolytic therapy for acute MI and STEMI
For acute myocardial infarction with ST
elevation or left bundle branch block:
* maximal chest pain is ≤6 hours
* beyond 6 hours and chest pain, consult a
specialist
* >6 hours and no chest pain, manage with
anticoagulants
* if on-going ischaemic pain
List the absolute contra-indications for thrombolytic therapy for acute MI and STEM
Absolute:
* streptokinase used within the last year, (not for alteplase)
* previous allergy,
* CVA within the last 3 months,
* history of recent major trauma,
* bleeding within the last month,
* aneurysms,
* brain or spinal surgery or head injury within the preceding
month, or recent (<3 weeks) major surgery,
* active bleeding or known bleeding disorder,
* aortic dissection.
List the relative contra-indication for Thrombolytic therapy for acute MI and STEMI
Relative (consult specialist):
* refractory hypertension,
* warfarin therapy,
* recent retinal laser treatment,
* subclavian central venous catheter,
* pregnancy,
* TIA in the preceding 6 months,
* traumatic resuscitation.
What to Note under Indications for thrombolytic therapy for acute MI and STEMI
Note: The mortality benefit of fibrinolysis is
highest when administered early after
symptom onset but is negligible if
administered to patients with symptom
durations exceeding 12 hours.
Thrombolytic therapy for acute MI & STEMI
After administration, monitor continuously what and note
Pulse
* BP
* Respiration depth and rate (count for a full minute)
* ECG
* Note: defibrillator should always be readily available including during
transport
When there is thrombus formation in setting of ACS what to use
Due to the role of thrombus formation in the setting of ACS, timely
and appropriate antithrombotic therapy is an important component
of optimal pharmacotherapy.
Antithrombotic therapy consists of what?
Antithrombotic therapy consists of
* antiplatelet and
* anticoagulant therapy.
explain the pathophysiologic process in arterial thrombosis
While platelets dominate the pathophysiologic process in arterial
thrombosis, the central role of thrombin in both platelet activation
and coagulation makes both types of therapy necessary in the acute
phase of treatment in a patient with ACS.
List the antiplatelet treatment
Clopidogrel
Aspirin, oral, 150 mg stat, then as daily single dose, continued
indefinitely in the absence of contraindications
Explain the action of antiplatelet treatment: aspirin
Provides its antiplatelet effect by acetylating a hydroxyl group of
serine 530 on the cyclooxygenase (COX) 1 enzyme on platelets and
thereby preventing the conversion of arachidonic acid into
prostaglandins, and eventually thromboxane A2.
Activity of Thromboxane A2
Thromboxane A2 produces platelet activation as well as
vasoconstriction.
