Drugs Flashcards
What are the indications for ADX?
Cardiac arrest, post ROSC circulatory support
What is the action of ADX?
Sympathomimetic that stimulates alpha and beta adrengenic receptors, enhances myocardial and cerebral blood flow during CPR, CPR therefore improved due to increased peripheral resistance which increases perfusion.
What are the cautions and contra-indications of ADX?
Severe hypertension with pts on beta blockers
DNA when temp < 30°C, double period between doses when 30°C<temp<35°C
What are the indications and contra-indications for atropine?
Bradycardia with ANY of:
Absolute bradycardia (<40BPM)
Hypotension
Paroxysmal ventricular arrythmias requring supression
Inadequate perfusion causing confusion etc.
Bradycardia following ROSC
DNA for hypothermic bradycardia or pts with heart transplants
What is the action of atropine?
Atropine is a muscarinic antagonist that blocks the affects of acetylcholine and other choline esters, decreasing vagal activity and enhancing A-V conduction.
What are the main side effects of atropine?
Dry mouth, blurred vision, pupil dilation, confusion, occasional hallucinations. Small doses (<100mg) can cause paradoxical bradycardia.
What are the indications and contra-indications of amiodarone?
Shockable cardiac arrest arrhythmias after 3rd shock
Contra-indicated in core temp <30ºC
When should you administer amiodarone during cpr?
After the 3rd shock and an additional bolus depending on age to unresponsive VF or pulseless VT following the 5th shock.
What is the action of amiodarone?
Blocks sodium and potassium channels, lengthening cardiac potential and therefore effective refractory period.
Acts to stabilise and reduce electrical irritability of cardiac muscles.
What are the usual side effects of amiodarone?
Bradycardia
Vasodilation/hypotension
Bronchospasm
Arrhythmias
What are the indications and contra-indications for benzylpenicillin?
Suspected meningococcal disease in the presence of:
Petechial/purpuric rash
and/or
signs/symptoms suggestive of meningococcal septicaemia
Contr-indications:
Known severe penicillin allergy (more than a simple rash alone)
What is benzylpenicillin?
A narrow-spectrum antibiotic
When should you use more than one injection site for IM benzylpenicillin?
When injecting more than 2ml of volume
What are the indications for chlorphenamine?
Relief of anaphylactic symptoms, should be given if symptoms fall short of anaphylaxis or after adrenaline if oral antihistamines are not suitable
What is the action of chlorphenamine?
Binds to the H1 histamine receptors blocking the action of endogenous histamine.
What are the contra-indications for chlorphenamine?
Known hypersensitivity
MAOI treatment within the last 14 days
What are the possible side effects of chlorphenamine?
Sedation and pyschomotor impairment (warn patients not to drive or do other complex tasks)
Dry mouth
Headache
Blurred vision
Urinary retention
GI disturbance
Convulsions (rare)
What patient demographics are more likely to experience the side effects of chlorphenamine?
Children and the elderly
What is the adult dose for IV Glucose?
10 gram (100ml)
What is the dose interval for IV Glucose?
5 minutes
How should IV glucose by flushed after administration?
Thoroughly (at least 20ml)
What are the indications and contra-indications for dexamethasone?
Indications:
Croup
Contra-indications:
Impending respiratory failure
What is the mechanism of dexamethasone?
Dexamethasone is a potent glucocorticoid with an anti-inflammatory action that decreases laryngeal mucosal oedema
Why should you be cautious when administering dexamethasone to children with possible or confirmed upper airway compromise?
Distressing the child may exacerbate airway compromise
What are the possible side effects of dexamethasone?
GI upset
Hypersensitivity/anaphylaxis
How many doses of dexamethasone can you administer, why?
One usually as dexamethasone has a long pharmacodynamic effect of 36-56 hours.
A second dose can be given with senior clinical advice or if the child vomits less that 30 mins after administration
What are the indications for ADM?
Anaphylaxis and life threatening asthma
What is the action of ADM?
Alpha and beta stimulation, causing peripheral vasoconstriction and central vasodilation
What is the initial adult dose for ADM?
500 micrograms/0.5 mg (0.5ml)
What are the indications and contra-indications for IM glucagon?
Hypoglycaemia when IV access is unsuccessful. Given once only
Contra-indications:
Pheochromocytoma
NOT FOR IV ADMINISTRATION
What is the initial adult dose for glucagon?
1mg (1ml)
What are the possible side effects of glucagon?
Nausea and vomiting
Abdominal pain in adults
Diarrhoea in children
Hypokalaemia
Hypotension in adults
Acute hypersensitivty reaction (rare)
What are the indications for hydrocortisone?
Severe or life threatening asthma
Exacerbation of COPD
Treatment and prevention of adrenal crisis
What is the initial dose for hydrocortisone?
100mg (1ml) SLOW intravenous (min 2 min) or IM
What are the indications for ipratropium bromide?
Acute, severe or life-threatening asthma
Acute asthma unresponsive to salbutamol
Exacerbation of COPD unresponsive to salbutamol
Expiratory wheezing
What is the initial dose for ipratropium bromide?
ONE dose NEB 250 mcg (1ml)
What are the indications and contra-indications for NLX?
The reversal of acute opioid or opiate toxicity for respiratory arrest or respiratory depression.
Contra-indicated for neonates born to opiate addicted mothers - administration can cause fatal withdrawal
What is the initial dose for NLX?
400mcg, IV IM or IN (half dose in each nostril for IN)
What is the half-life of naloxone?
30-80mins
What is aspirin?
A non-selective cyclooxygenase (COX) inhibitor, with inhibition of platelet aggregation
How does aspirin reduce temperature?
It inhibits COX1, preventing prostaglandin from being formed and stimulating the hypothalamus causing it to raise the set point if the hypothalamic thermostat for body temperature
Why is aspirin not administered to paediatric patients?
Associated mitochondrial damage associated with Salicylic acid production when aspirin is processed in the liver, this can cause acute liver failure and encephalopathy (Reye’s syndrome)
What is the initial adult dose for aspirin?
300mg (1 tablet)
What are the cautions of aspirin?
Asthma
Pregnancy
Renal failure
Gastric or duodenal ulcers
Current anti coagulant medications
Moderate hepatic failure
What are the contra indications of aspirin?
Known allergy
Active GI bleed
Clotting disorders
Severe hepatic failure
<16 years old
What can suggest severe rather than moderate liver failure?
Jaundice
Ascites
Encephalopathy
How can aspirin cause aspirin induced asthma?
The mechanism of action forces the lipoxygenase pathway which causes inflammation
Why don’t you administer aspirin to patients with GI bleeds?
Prostaglandins provide protection to the gastric mucosa, aspirin blocking COX1 and therefore prostaglandins makes the stomach vulnerable to damage
What is the mode of action of GTN?
GTN is converted to Nitric Oxide in the blood stream, it then diffuses into the venous wall and causes relaxation of vascular smooth muscle causing dilation of coronary arteries and sytemic veins
How does GTN relieve pressure on the heart?
Dilating blood vessels systematically, thereby lowering pre-load and afterload
What are the indications for GTN?
Cardiac chest pain due to angina or MI when sBP > 90mmHg
Consider administering GTN in acute heart failure with ischaemia or uncontrolled hypertension
Pts with suspected cocaine toxicity presenting with chest pain
What are the contraindications of GTN?
Hypotension (sBP < 90 or <100 in AHF)
Hypovolaemia
Cerebral haemorrhage
Sildenafil and other related drugs in last 24hrs
Unconscious pts
Known severe aortic or mitral stenosis
Why is sildenafil a contraindication of GTN?
Sildenafil and other phosphodiesterase inhibitors along with GTN and other nitrates due to the possibility of profound hypotension
Why is GTN contraindicated for patients with severe aortic or mitral stenosis?
Patients with severe aortic or mitral stenosis rely on a certain amount of afterload to maintain their cardiac output, their hearts would struggle to cope with a sudden drop in blood pressure
What are the cautions for GTN?
Patients with suspected posterior MI or right ventricular infarction
What is the initial adult dose for GTN?
Unstable angina or MI when sBP > 90mmHg:
400-800mcg (1-2 sprays) or 1 tablet of 300/500/600mcg, 5-10min interval, no limit
AHF when sBP > 110mmHg:
400-800mcg (1-2 sprays) or 1 tablet of 300/500/600mcg, 5-10min interval, 6 sprays or 1.8mg total in tablets
What are the side effects of GTN?
Headache
Hypotension
Dizziness
What is salbutamol?
Adrenoceptor Beta 2 non-catcholamine agonist
What type of drug is sildenafil?
phosphodiesterase inhibitor
For patients with chest pain from suspected MI or angina, what must their blood pressure be for you to administer GTN?
Above 90 systolic
For patients with pulmonary oedema, what must their blood pressure be for you to administer GTN?
Above 110 systolic
Why is asthma a caution of aspirin?
Aspirin can cause bronchoconstriction in some asthmatic patients through increased production of pro-inflammatory mediators, particularly leukotrienes, from the lipoxygenase pathway being activated after Cox-1 inhibiton.
Why is pregnancy a caution of aspirin?
Aspirin may be associated with neonatal bleeding complications and premature closure of the ductus arteriosus (DA), resulting in pulmonary vasculature abnormalities and persistent pulmonary hypertension of the newborn (PPHN).
Also associated with an increased incidence of postpartum hemorrhage.
However this is usually only in chronic exposure of more than 300mg a day from 30 weeks.
Why is renal failure a caution of aspirin?
Aspirin is an NSAID which inhibits the excretion of renal prostaglandin, a vasodilator.
Because of this the renal vessels cannot compensate against the vasoconstrictors released by the body, causing nephrotoxicity.
Why is moderate hepatic failure a caution of aspirin?
Aspirin is an NSAID like ibuprofen which damages the liver but only mildly
What is the action of salbutamol?
Activation of the beta 2 receptors causes an increase in (cAMP) inactivating myosin light chain kinase and decreasing intracellular calcium levels, causing broncho-relaxation.
What are the contraindications of salbutamol?
None in the emergency setting
What are the cautions of salbutamol?
Hypertension
Angina
Pts on beta blockers with hypertension
Hyperthyroidism
Late pregnancy
Why are hypertension and angina cautions of salbutamol?
Due to beta 2 adrenoceptors being present in the heart, SLB can increase heart rate possibility leading to arrhythmias or worsened ischemia
What are patients on beta blockers with hypertension a caution of salbutamol?
Salbutamol is a beta agonist, causing a competition between two drugs which may result in severe hypertension
Why is hyperthyroidism a caution of salbutamol?
Salbutamol can stimulate thyroid receptors as they are also G protein coupled, leading to an increase in hyperthyroid symptoms
Why is late pregnancy a caution of salbutamol?
Beta 2 receptors are present in the uterus, SLB may cause relaxation and stop contractions
What are the main side effects of salbutamol?
Tachycardia & palpitations
Tremor and muscle cramps
Peripheral vasodilation
Headaches
Feeling of tension
Rash
What is ipratropium bromide?
Muscarinic antagonist
What is the action of ipratropium bromide?
It inhibits effect of acetylcholine on muscarinic receptors in patients smooth muscle of the airways
What are the indications of ipratropium bromide?
Acute severe or life threatening asthma or exacerbation of COPD when unresponsive to salbutamol.
What are the cautions of ipratropium bromide?
Glaucoma
Pregnancy and breastfeeding
Prostatic hyperplasia
What are the main side effects of ipratropium bromide?
Possible allergic reaction
Sympathetic effects:
Dry mouth, tachycardia, tightness, nausea etc
Why is ipratropium bromide only administered once?
It has a long half life, effects can last 3-6 hours.
What are the cautions of ADM?
Severe hypertension with patients on non-cardioselective beta blockers
What are the contraindications of chlorphenamine?
Know hypersensitivity
Patients who have been treated with monoamine oxidase inhibitors MAOIs in the last 14 days
Why are MAOIs contraindicated for chlorphenamine?
The anticholinergic properties of chlorphenamine are intensified by monoamine oxidase inhibitors (MAOIs).
What are the contraindications of entonox?
Severe head injuries with impaired consciousness
Decompression sickness (diving within the last 24 hours)
Violently disturbed psychiatric patients
Intraocular injections in the last 8 weeks
Suspected bowel obstruction
What are the cautions of entonox?
Any patient at risk of having a pneumothorax, pneumomediastinum and/or a pneumoperitoneum (e.g. polytrauma, penetrating torso injury).
What is ibuprofen?
An NSAID
How do NSAID work?
Cyclooxygenase (COX) inhibition. Cyclooxygenase is required to convert arachidonic acid into thromboxanes, prostaglandins, and prostacyclins.
Why is ibuprofen not advised in the first 48 hours of soft tissue injury?
The inflammatory response is useful to the body and you don’t always want to inhibit it
Why are ibuprofen and other NSAIDs contraindicated for patients with heart failure?
They can cause the kidneys to retain more salt, increasing heart failure risk
Why is chicken pox a contraindication of ibuprofen?
Risk of infection due to suppression of inflammatory response
What is the action of paracetamol?
True mechanism not fully understood, selective inhibition of COX3 is suspected
What are the indications for paracetamol?
Mild pain and fever with discomfort
Why is paracetamol run over 15 minutes?
Rapid administration may cause hypotension
What is nitroprusside?
Sodium nitroprusside is a potent vasodilator used in management of acute hypertension
Why are steroids given last in acute respiratory distress?
They have a slow mode of action
What is the mode of action of ipratropium bromide?
Ipratropium is an acetylcholine antagonist via blockade of muscarinic cholinergic receptors
Blocking cholinergic receptors decreases the production of cyclic guanosine monophosphate (cGMP). This decrease in the lung airways will lead to decreased contraction of the smooth muscles.
What medications are commonly found in inhalers?
Short Acting Beta-2 Agonists (SABA) e.g. albuterol, salbutamol
Long Acting Beta-2 Agonists (LABA) e.g. salmeterol, formoterol
Long Acting Anti-Muscarinic (LAMA) e.g. ipratropium, tiotropium
Corticosteroids e.g. beclamethasone, fluticasone
What kind of drug is TXA?
An anti-fibrinolytic
What is the action of TXA?
It prevents the breakdown of clots (anti-fibrinolytic)
TXA is a synthetic reversible competitive inhibitor to the lysine receptor found on plasminogen. The binding of this receptor prevents plasmin (activated form of plasminogen) from binding to the fibrin matrix, stabilising it.
What are the indications for TXA?
Significant external or internal haemorrhage (known or suspected)
PPH with continued bleeding
Head injuries with reduced GCS (<13)
What is the window from start of bleeding for TXA administration?
3 hours
What are the contra-indications of TXA?
Previous anaphylactic reaction to TXA
Bleeding started >3hrs ago
Obvious resolution of haemorrhage
Is TXA indicated for gastro-intestinal bleeds?
Current evidence does not support the use of TXA for GI haemorrhage
What is the adult dose for TXA?
1 gram (10ml) over 10 min
When could you re-administer TXA?
For PPH if bleeding does not stop 30 mins after first dose
How can TXA be administered?
IV/IO - SLOWLY over 10 mins (1ml/min)
IM - into large muscle or divided into two doses given bilaterally
How is morphine presented and adminstered IM/SC and IV?
Comes in 1mg, 1ml vials
IV:
Must be incorperated with 9ml of saline in a 10ml syringe to give 1mg in 10ml of morphine
IM/SC:
Do not dilute
What are the contra-indications of morphine?
Children under 1 years
Respiratory depression (RR<10 adult, <20 children)
Hypotension
Head injury with significantly impaired consciousness
Known hypersensitivity
What are the cautions of morphine?
Sever renal or hepatic impairment
Pregnancy - EXTREME CAUTION
Chest injuries - GREAT CAUTION
Respiratory problems (COPD, asthma)
Acute alcohol intoxication
Medications
What medications should morphine be used cautiously in the presence of?
Anti-depressants
Sedatives
Major tranquilizers
What are the side effects of morphine?
Respiratory depression
Cardiovascular depression
Nausea and vomiting
Drowsiness
Pupillary constriction
What GCS is needed for TXA to be indicated for head injury patients?
<13
Why is paracetamol not considered an NSAID when it is a COX inhibitor?
Because it has little anti-inflammatory activity. It treats pain mainly by blocking COX-2 mostly in the central nervous system, but not much in the rest of the body.
What are the indications and contra-indications of ondansetron?
Treatment of nausea and vomiting (including the prevention of that induced by opiates) in adults and children (travel related for children)
Contra-indications:
Known sensitivity
Infants <1 month old
Congenital long QT syndrome
What are the side effects of ondansetron?
Hiccups
Flushing
Constipation
Headache
Seizures
Movement disorders
Hypotension
Chest pain
Arrythmias
Bradycardia
Injection site reactions
What is the mode of action of ondansetron?
It is an anti-emetic that blocks 5HT receptors both centrally and in the GI tract
What is glucagon and where is it produced within the body?
A pancreatic hormone produced by the pancreatic A cells
What is naloxone and what is its mode of action?
It is an opiate antagonist that binds to the μ (mu) receptors on neuronal cells in the brain and blocks opioids
What are the actions of glucagon?
Prompts glycogenolysis, the breakdown of glycogen
Stimulates gluconeogenesis, the production of glucose from amino acids in the liver
What are the indications and contra-indications of glucagon?
Hypoglycaemia in known diabetics or when oral glucose is not possible i.e. dysphasia or unconsciousness
Contra-indicated for:
Low glycogen stores
Hypoglycaemic seizures
Why are low glycogen stores or hypoglycaemic seizures a contraindication of glucagon?
Glucagon does not contain glucose it stimulates the release of stores already in the body, if those stores are low because of fasting, starvation, recent glucagon use or exertion (as in seizures) it will have little effect
What is the presentation of glucagon?
1mg of powder for reconstitution with water for injection
