Week 6 Study Notes - week 6 PDF

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Week 6 Important Terminology Drug Class (type of drug) A drug may be classified by the chemical type of the active ingredient or by the way it is used to treat a particular condition. Each drug can be classified into one or more drug classes. E.g. Midazolam drug class – Benzodiazepine (short acting) Benzodiazepine drugs – mild sedative type medication E.g. Atropine drug class – Anticholinergic (antimuscarinic) E.g. Paracetamol drug class – analgesic & Antipyretic Pharmacology The science and study of the preparation, properties, nature, uses and actions of drugs E.g. Midazolam pharmacology Midazolam hydrochloride is a short acting CNS depressant that induces amnesia, anaesthesia, hypnosis and sedation. It achieves this by enhancing the action of the inhibitory neurotransmitter gamma-amino butyric acid (GABA). Depressant effects occur at all levels of the CNS. E.g. Morphine pharmacology Morphine is a narcotic analgesic that acts on the central nervous system by binding with opioid receptors, altering processes affecting pain perception and emotional response to pain. It also combines to cause respiratory depression, vasodilation, decreases in the gag reflex and slows AV node conduction. Metabolism Where in the body is the drug broken down or absorbed and excreted (basic) E.g. Midazolam metabolism • By the liver and excreted by the kidneys E.g. Morphine metabolism • By the liver, kidneys and lungs E.g. Aspirin metabolism • Aspirin is converted to salicylic acid in many tissues, but primarily in the GI mucosa and liver. It is subsequently excreted by the kidneys. E.g. Glucose 5% metabolism • Broken down in most tissues and distributed throughout total body water. Drug Schedule • All drugs and poisons are scheduled from Schedule 1 – Schedule 9 (S1 – S9)

• • • •

S2, S4 and S8 are the common drug schedules relevant to use. S2 – over the counter pharmacy drugs e.g. Panadol, aspirin S4 – Prescription only drugs e.g. Hydrocortisone, Midazolam, Methoxyflurane, Ondansetron S8 – Controlled Drugs e.g. Morphine, Fentanyl, Ketamine

Indications • This is a need to know as a paramedic • When a drug should be given • What medical condition or patient presentation would require this drug E.g. Paracetamol indications • Minor pain • Fever (causing distress) E.g. Adrenaline indications • Anaphylaxis or severe allergic reaction • Severe life-threatening bronchospasm or silent chest (patients must only be able to speak in single words and/or have haemodynamic compromise and/or ALOC • Bradycardia with poor perfusion (unresponsive to atropine and/or TCP) • Cardiac arrest • Croup (with stridor at rest) • Shock unresponsive to adequate fluid resuscitation (excluding haemorrhagic cause) Contraindications • Also, a need to know as a paramedic • When to not give a drug • May be potential harmful to the patient • E.g. a previous reaction, age group, vital sign or medical condition E.g. Glyceryl Trinitrate contraindications • KSAR (Known severe allergic/adverse reaction) or hypersensitivity to GTN • Heart rate 150 bpm • Systolic BPP < 100mmHg • Acute CVA • Head trauma • Phosphodiesterase inhibitor medication administration (e.g. Viagra or Levitra) in the previous 24 hours) E.g. Glyceryl Trinitrate contraindications • KSAR or hypersensitivity to paracetamol • Patients < 1 month old E.g. Methoxyflurane contraindications • KSAR or hypersensitivity to methoxyflurane • Patients < 1 year • History of significant liver or renal disease • History of malignant hyperthermia Precaution • Not contraindication • Conditions that may potentially have adverse side effects if given this drug E.g. Adrenaline precautions • Hypertension • Hypovolaemic shock • Concurrent MAOI therapy • Multiple Sclerosis **Conditions that may be adversely affected by adrenaline however it depends on patient presentation E.g. Glyceryl Trinitrate precautions • Suspected inferior AMI • Cerebral vascular disease • Risk of hypotension and/or syncope • Intoxication (GTN effects are enhanced) • Phosphodiesterase inhibitor medication administration (e.g. Viagra or Levitra) in the previous 4 days)

E.g. Aspirin precautions • Possible aortic aneurysm or any other condition that may require surgery • Pregnancy • History of GI bleeding or peptic ulcers • Concurrent anticoagulant therapy (e.g. warfarin) Side Effects • Unwanted effects of a drug • Not part of its desired therapeutic effect E.g. Adrenaline side effects • Anxiety • Hypertension • Palpitations/tachyarrhythmias • Pupil dilation • Tremor E.g. Glycerol Trinitrate side effects • Dizziness • Hypotension • Syncope • Reflex tachycardia • Vascular headaches Adverse Reaction • Unintended and unpredictable reaction to a drug • Drug given in correct dose by proper route • Not included in DTP’s due to being a unexpected reaction Allergic Reaction • Occurs when the body comes into contact with a substance that the immune system recognises as a danger. • Usually only affects one body system – ranges from mild to severe. - Urticaria/Hives - Angioedema - Swollen tongue Anaphylaxis • Acute, life threatening • Systemic – affects more than one body system • Left untreated death is likely to occur Presentation • In DTP’s includes physical presentation e.g. Ampoule, minijet, nebule, plastic container, soft infusion pack, tablet, spray etc. • Also includes dose and amount of fluid in the ampoule e.g. 1mg/1ml, 5mg/1ml, 10mmol/5ml

Glass Ampoule

Glass Ampoule – Glucagon

Tablet

Nebule (Polyamp)

Soft infusion bags/plastic container

Spray

Drugs carried by QAS in glass ampoules – e.g. midazolam, adrenaline, fentanyl, morphine, ondansetron Presentations in different Ambulance Services Adrenaline QAS Ampoule, 1mg/1 mL (1:1,000) adrenaline Ampoule, 1mg/10 mL (1:10,000) adrenaline NT Ampoule, 1mg/1 mL (1:1,000) adrenaline Ampoule, 1mg/10 mL (1:10,000) adrenaline Minijet Ampoule, 1mg/10mL (1:10,000) adrenaline Salbutamol QAS Nebule, 5mg/2.5 mL salbutamol Ampoule, 500 micro/ 1 mL salbutamol AMB VIC 5mg in 2.5 mL polyamp 500mcg in 1mL glass ampoule 5mg in 5mL glass ampoule Normal Saline QAS Ampoule, 10 mL sodium chloride 0.9% Viaflex plastic container, 100 mL sodium chloride 0.9% Viaflex plastic container, 500 mL sodium chloride 0.9% Viaflex plastic container, 1000 mL sodium chloride 0.9% BD PosiFlush 5mL Pre-filled sodium chloride 0.9% NT Ampoule, 10 mL sodium chloride 0.9% 1000mL soft infusion pack, sodium chloride 0.9%

100mL soft infusion pack, sodium chloride 0.9%

Dose • The dose or strength of medication written on the ampoule, bag, nebule, etc. • 5mg/1ml means there is 5mg of medication diluted in 1ml of fluid (saline, water for injection) Adrenaline • 1mg/1ml 1:1000 • 1mg active ingredient • 1ml diluting fluid • Concentration is 1:1000 • • • •

1mg/10ml 1:10 000 1mg active ingredient 10ml diluting fluid Now concentration diluted to 1:10 000

Onset • The length of time before the drug becomes effective. • Onset is effected by route of administration • IV faster than IM • IM faster than subcut Adrenaline • 30 seconds (IV) • 60 seconds (IM) Hydrocortisone • 1-2 hours Morphine • 5-10 minutes (peak 20-30 minutes (IM)) / • 2-5 minutes (peak 20 minutes (IV)) Duration • Length of time a drug remains effective • Can be effected by amount of drug given, the preparation of the drug, metabolism of the drug, disease processes. Adrenaline • 5-10 minutes Hydrocortisone • 6-12 hours Half-Life Amount of time until ½ of the drug has been metabolised Adrenaline • 2 minutes Ketamine • 10-15 minutes E.g. Ketamine

Onset (IV) 30 seconds

Duration (IV) 5-2o minutes

Half-life 10-15 minutes...