Pharmacology Flashcards
Adrenaline
Pharmacology
A naturally occurring alpha and beta adrenergic stimulant.
Actions:
- increase HR by increasing SA node firing rate (beta 1)
- increasing conduction velocity through AV node (beta 1)
- increasing myocardial contractility (beta 1)
- increase irritability of the ventricles (beta 1)
- causes bronchodilation (beta 2)
- causes peripheral vasoconstriction (alpha)
Adrenaline
Primary Indications
- Cardiac arrest VF, VT, asystole or PEA
- Inadequate perfusion: cardiogenic, non cardiogenic, non hypovolaemic
- Bradycardia with poor perfusion
- Anaphylaxis
- Severe asthma, imminent life threat not responding to neb therapy or unconscious with no BP
- Croup
Adrenaline
Contraindications
Hypovolaemic shock without adequate fluid replacement.
Adrenaline
Precautions
- Elderly/frail
- Patients with CVD
- Patients on MAOIs
- Higher doses may be required for patients on beta blockers
Adrenaline
Side Effects
- Sinus tachycardia
- Supraventricular arrhythmias
- Ventricular arrhythmias
- Hypertension
- Pupillary dilation
- May increase size of MI
- Feeling of anxiety/palpitations in the conscious patient
Aspirin
Pharmacology
An analgesic, antipyretic, anti inflammatory and anti platelet aggregation agent
Actions:
1. Minimise platelet aggregation and thrombus formation in order to retard the progression of coronary artery thrombosis in ACS
- Inhibits synthesis of prostoglandins - anti inflammatory actions
Aspirin
Contraindications
- Hypersensitivity to aspirin/salicylates
- Actively bleeding peptic ulcer
- Bleeding disorders
- Suspected dissection aortic aneurysm
- Chest pain assoc with psychostimulant OD with BP > 160
Aspirin
Precautions
- Peptic ulcer
- Asthma
- Patients on anti coagulants
Aspirin
Side effects
- Heartburn, nausea, gastrointestinal bleeding
- Increased bleeding time
- Hypersensitivity reactions
Dexamethasone
Pharmacology
A corticosteroid secreted by the adrenal cortex
Actions
- relieves inflammation
- provided immunosuppression
Dexamethasone
Primary Indications
- Bronchospasm associated with acute resp distress not responding to neb therapy
- Moderate-severe croup
- Acute exacerbation of COPD
- Adult stridor (non-foreign body obstruction)
Dexamethasone
Contraindications
Known hypersensitivity
Dexamethasone
Precautions
Solutions which are not clear or are contaminated should be discarded
Fentanyl
Pharmacology
A synthetic opioid analgesic agent
Actions CNS - depression leading to analgesia - resp depression leading to apnoea - dependance leading to addiction
CV
- decrease conduction velocity through the AV node
Fentanyl
Primary indications
- Sedation to facilitate intubation RSI modified or paed IFS
- Sedation to maintain intubation
- Sedation to facilitate transthoracic pacing
- Sedation to facilitate sync cardioversion
- CPR interfering patient ALS
- Analgesia IV/IN
- history of hypersensitivity or allergy to morphine
- known renal impairment/failure
- short duration of action desirable
- hypotension
- nausea and vomiting
- severe headache
Fentanyl
Containdications
- History of hypersensitivity
2. Late second stage labour
Fentanyl
Precautions
- Elderly/frail
- Impaired hepatic function
- Resp depression: COPD
- Current asthma
- Patients on MAOI
- Known addiction to opioids
- Rhinitis, rhinorrhea, or facial trauma (IN)
Fentanyl
Side Effects
- Respiratory depression
- Apnoea
- Rigidity of diaphragm and intercostal muscles
- Bradycardia
GTN
Phamacology
Principally a smooth muscle relaxant
Action
- venous dilation promotes venous pooling and reduces venous return to the heart (reduced preload)
- arterial dilation reduces systemic vascular resistance and arterial pressures (reduced afterload)
The effects of above
- reduced myocardial 02 demand
- reduces sys,dia and MAP whilst usually maintaining coronary perfusion pressure
- mild collateral coronary arterial dilation may improve blood supply to ischaemic areas of myocardium
- mild tachycardia secondary to slight drop in BP
- preterm labour: uterine quiescence in pregnancy
GTN
Primary indications
- Chest pain with ACS
- Acute LVF
- Hypertension associate with ACS
- Autonomic dysreflexia
- Preterm labour (consult)
GTN
Contraindications
- Known hypersensitivity
- Systolic BP < 110 (tablet)
- Systolic BP <90 (patch)
- Sildenafil (viagra), vardenafil (levitra) in the last 24hours, or tadalafil (cialis) in the last 4 days
- HR > 150bpm
- Bradycardia <50 except autonomic dysreflexia
- VT
- Inferior STEMI with BP < 160
- Right ventricular MI
GTN
Precautions
- No previous administration
- Elderly patients
- Recent MI
- Concurrent use with other tocolytics
GTN
Side effects
- Tachycardia
- Hypotension
- Headache
- Skin flushing (uncommon)
- Bradycardia
Ipratropium Bromide
Pharmacology
Anticholinergic bronchodilator
Action
Allows bronchodilation by inhibiting cholinergic bronchomotor tone i.e. blocks vagal reflexes which mediate bronchoconstriction
Ipratropium Bromide
Primary indications
- Severe resp distress assoc with bronchospasm
2. Exacerbation of COPD irrespective of severity
Ipratropium Bromide
Contraindications
Known hypersensitivity to atropine or its derivatives
Ipratropium Bromide
Precautions
- Glaucoma
2. Avoid contact with eyes
Ipratropium Bromide
Side Effects
- Headache
- Dry mouth
- Palpitations
- Tachycardia
- Skin rash
- Nausea
- Acute angle glaucoma secondary to direct contact with eyes
Ketamine
Pharmacology
Anaesthetic agent with analgesic properties at lower doses
Exact mechanisms of action is unclear, but primarily works as an antagonist at NMDA receptors.
Ketamine may also interact with opioids, muscarinic and other receptors. Produces a trance like dissociative state with amnesia, with preservation of laryngeal and pharyngeal reflexes.
Ketamine
Primary indications
- Intubation
- Analgesia
- Sedation, agitation and movement during CPR
Ketamine
Contraindications
Suspected non-traumatic brain injury with severe hypertension BP > 180
Ketamine
Precautions
May exacerbate cardiovascular conditions e.g. uncontrolled hypertension, stroke, recent MI, cardiac failure due to effects of HR and BP
Ketamine
Adverse effects
CV: hypertension, tachycardia
CNS:
- emergence reactions (vivid dreams, restlessness, confusion, hallucinations, irrational behaviour).
- increased skeletal muscle tone (may resemble seizures)
Resp
- transient resp depression and apnoea
GI
- nausea and vomiting
Other
- injection site pain, lacrimation, hypersalivation, diplopia, nystagmus
Lignocaine
Pharmacology
Sodium channel blocker. Interrupts impulse conduction in peripheral nerves and stabilises excitable cell membranes
Lignocaine
Indications
Local anaesthetic to reduce pain associated with
- IM ceftriaxone
- chest decompression in patients with GCS > 10
- IO administration of medication or fluid in a conscious patient
Lignocaine
Contraindications
Known hypersensitivity to lignocaine or related local anaesthetic (bupuvacaine, levobupivacaine, prilocaine, ropivacaine)