Pharmacology

1. Pharmacology Gimme ‘da DRUGS, man!

2. Case • During the transport of an ACS patient, you notice that after giving nitroglycerin, their blood pressure drops to s*&#! (S*&#! = 50/palp). As you wonder “how did nitroglycerin drop it that low” you give a fluid bolus but also grab the Dopamine. “How does Dopamine work? How do I give it? What are the side effects?” You ponder, noticing a bit late that your patient has been unconscious for the past 10 seconds, in V-fib. Things just went from S*&#! to F*&#!...

3. Pharmacology Terms • Generic Name/Trade Name: different names depending on who is making it. Examples: acetaminophen/Tylenol, fentanyl/Sublimaze, hydromorphone/Dilaudid. • Mechanism of Action: how it works in the body • Pharmacokinetics – how it is absorbed, distributed, and eliminated from the body • Dosage/Route – how much and where (oral, rectal, nasal, IV, IM, subcutaneous) • Indications/Contraindications – what its used for, what will prevent you from giving it. • Adverse effects – things that might go wrong if you give it

4. Drug Metabolism • Therapeutic levels – range of serum levels in which drug will have its predicted value • LD50 – level at which drug will kill 50% of the patients given the drug • Metabolism – how the body transforms the drug to make it inert and ready for removal • Excretion – how the drug exits the body • Liver/fecal • Kidney/urine • Combination

5. The Six Rights • Right Drug • Right Patient • Think Mass Casualty situations • Right Dose • Have a reference handy • Right Time • Right Route • Right Documentation • Time, who gave it, what happened!!

6. How does a drug work? • Receptor • A protein made by the cell, nestled in the cell wall that acts as a signal sentinel. • Acts in response to this signal in a certain way • Usually by a second messenger system • The structure of the receptor is such that it can be stimulated, overstimulated, or blocked from acting. • The second messengers cause the production of enzymes

7. How does a drug work? • Stimulate a receptor • epinephrine, dopamine, Narcotics, Benzos, succinylcholine, albuterol • Block a receptor • lidocaine, aspirin, Narcan, Vecuronium, atropine, adenosine, amiodarone, diphenhydramine • Directly effect body chemistry/osmolarity • electrolytes, bicarb, NaCl, mannitol • Act as an enzyme or catalyst • tPA, thiamine, cyanocobalamin • Block an enzyme • Act as substrate for a chemical reaction • Mucomyst, nitroglycerin, oxygen, glucose • Kill Bugs - antibiotics

8. Autonomic Nervous System • Sympathetic • Alpha (1, 2) • Constricts blood vessels, dilates pupils • Beta • 1 – increases heart rate • 2 – dilates bronchioles, arterioles • Parasympathetic • Muscarinic • Relaxes smooth muscle (except bronchioles) • Decreases heart rate, electrical conduction • Constricts pupils

9. Other Nervous System Receptors • GABA • Causes a decrease in neuronal activity • Opioid • Block pain reception in the spinal cord • Causes euphoria (mu receptor) • Acetylcholine • Allows for transmission of nerve impulse to a muscle group – contracts muscle • Dopamine • Poorly understood, neuronal signaling and cognition

10. The EMT formulary • Aspirin (Ecotrin, Bayer) • Action: Thromboxane A2 inhibitor, causes platelet function inhibition • Dosage: 324mg oral chewed • Indications: Cardiac chest pain • Contraindications: Allergy, GI bleeding • Side Effects – bleeding, GI upset

11. EMT Formulary • Nitroglycerin (EMT can assist patient with his/her own, AEMT and medic can give without prior Rx) • Effect: vasodilator, chest pain reliever • Dosage: 0.4mg sublingual Q 15 min x3 • Indications: chest pain • Contraindications: hypotension, allergy • Side Effects: Headache, hypotension, syncope, cardiac arrest

12. EMT formulary • Albuterol (Proventil) • Effect: Dilates smooth muscle in bronchioles (B2) • Dosage: 1-2 puffs per MDI PRN (max three doses); AEMTs and Medics – 1 ampule neb prn, max 3 • Indications: Asthma or COPD exacerbations • Contraindications: none • Side Effects: jitteriness, tachycardia, arrhythmia, sweating, anxiety

13. EMT formulary • Epinephrine (EpiPen, EpiPenJr) • Effect: A1, A2, B1, B2 receptor agonist – vasocontricts, relaxes bronchiole smooth muscle, increases heart rate • Dosage: EMTs: EpiPen (0.3ml) or EpiPenJr (0.15ml) • Dosage: AEMTs: 0.3ml 1:1000 IM, or 0.15ml for 15-30kg • Dosage: Medics: as above, or 0.1-0.5mg iv 1:10,000 for anaphylaxis, 0.1mg/kg, max 1mg IV Q5 min for arrest • Indications: Anaphylaxis, severe asthma (medical control), cardiac arrest • Contraindications – none • Side Effects: arrhythmia, hypertension, MI, jitteriness

14. EMT Formulary • Oxygen • Effects: acts as a metabolic substrate for respiration, energy production • Dosage: 2-15lpm via NC (max 6lpm), or oxymask • Indications: hypoxia, respiratory distress, stroke like syndromes • Contraindications: open flame • Side Effects: hyperoxia indicated in free radical formation and increased cell damage.

15. AEMT formulary (State Mandated) • Dextrose/Glucagon • Reviewed in Diabetic Emergencies Lecture • Diphenhydramine (Benadryl) • Reviewed in Anaphylaxis Lecture • Naltrexone (Narcan) • Effects: opioid receptor antagonist • Dosage: 0.4mg IV Q5 min until desired effect, max 2mg • Indications: altered mental status, narcotic OD • Contraindications: alert patient • Side Effects: pain, agitation, vomiting, injury to EMT if patient not restrained.

16. AEMT formulary • Benzodiazepines (diazepam/Valium; medazolam/Versed) • Effects: GABA receptor agonist – increase seizure threshold, sedating effects • Dosage: Valium (long acting) .1-.2mg/kg IV, IM or PR (gel) max 5-10mg x1 dose • Versed (medium acting) .02-.05mg/kg max 4mg x1 • Indications :Seizures, acute severe agitation, bath salts • Contraindications: respiratory depression, sedation, high risk airway, allergy • Side Effects: miosis, respiratory depression, need for intubation

17. AEMT formulary • Narcotics (morphine; fentanyl) • Effects: opioid agonist – provides pain relief • Dosage: Morphine 0.1mg/kg IV/IM max 10mg for pain • Fentanyl – 0.5-1 mcg/kg iV max 50mcg x1 SLOW • Medical control for any further dosing • Indications: acute traumatic pain, cardiac pain (morphine only) • Contraindications: abdominal pain, allergy, respiratory depression or altered mental status • Side Effects: Chest Wall Rigidity syndrome, respiratory depression, hypotension

18. Paramedic Formulary • Zofran • Effect: Reduction of nausea through inhibition of serotonin 5-HT3 receptor • Dosage: 4mg IV/ODT for Adults and Children 6 and older • 2mg IV/ODT children 2-6 • 1mg IV children 6 months-2 years • Indications: nausea and vomiting • Contraindications: allergies • Side effects: may prolong QT, headache

19. Paramedic Formulary • Phenergan • Effects: reduces nausea and vomiting via dopamine receptor antagonism • Dosage: 25mg IM for adults only. Pediatric use not permitted • Indication: nausea and vomiting • Contraindication: sedation, allergy • Side Effects: respiratory depression, extrapyramidal symptoms (dystonic reaction), anxiety, hypotension

20. Paramedic Formulary • Haldol • Effects: sedation and reduction of psychotic symptoms via dopamine receptor antagonism • Dosage: 2.5mg-5mg IM/2mg IV • Indication: acute psychosis, severe agitation, second line to maxing out your benzos for bath salts. • Contraindications: allergies, prolonged QT syndrome • Side Effects: sedation, Torades de Pointe, ventricular tachycardia, dystonia.

21. Paramedic Formulary • Ketamine • Effect: produces dissociative state through limbic system interaction • Dosage: 1-2mg/kg IV or 3-4mg/kg IM • Indications: induction agent • Contraindications: Theoretical – increased ICP, increased IOP, allergy • Side effects: laryngospasm, emergence reactions, excessive drooling

22. Paramedic Formulary • Paralytics (Rocuronium/Vecuronium) • Effect: inhibits release of acetylcholine at the neuromuscular junction causing paralysis • Dosage: Vecuronium: 0.1mg/kg IV • Rocuronium: 1mg/kg IV • Indications: paralytic agent for RSI • Contraindications: difficult airway, insuffient expertise in airway management • Adverse Reactions: death

23. Paramedic Formulary • Solu-Medrol • Effects: corticosteroid - reduces inflammation and immunity through multiple messengers and interactions • Dosage: 1mg/kg IV, max 125mg IV • Indications: asthma, COPD, anaphylaxis • Contraindications: allergy • Side Effect: hyperglycemia, jitteriness, immunosuppression, renal impairment, GI bleeding

24. Paramedic Formulary • Vasopressin • Effect: hormone – constricts blood vessels and improves cardiac contractility • Dosage; 40 units x1 dose in lieu of first epi for cardiac arrest. • Indications: cardiac arrest • Contraindications: none • Side effects: none in prehospital setting

25. Paramedic Formulary • Lidocaine • Effects: Sodium Channel Blockade, inhibiting nerve conduction for pain, and delaying ventricular automaticity • Dosage: V-tach/V-fib – 1mg/kg IV x1 • IO needle pain – flush IO tubing with lidocaine and push through with first normal saline flush • Indications – v-tach/v-fib, IO injection site pain • Contraindications: allergy • Side effects: complete heart block, ventricular arrest, seizures

26. Paramedic Formulary • MARK I Kit • Effects: Reverses the effects of organophosphate poisons • Dosage : 1 kit, repeat in 5 min as needed • Contains: Atropine 1mg • 2-PAM Chloride 600mg • Indications: organophosphate poisoning, WMD event • Contraindications: none in this setting • Side Effects: blurred vision, headache, dizziness, nausea, tachycardia

27. Paramedic Formulary • Magnesium Sulfate • Effect: relaxes smooth muscles in bronchioles, uterus, stabilizes cardiac membranes • Dosage: 1-2 gm IV in adults over 20 minutes for asthma (medical control required), 1-2gm IV push for Torsades • Indications: severe asthma, Torsades, preterm labor • Contraindications: hypermagnesemia • Side Effects: paralysis, respiratory depression

28. Paramedic Formulary • Amiodarone • Effect: Antiarrhythmic – multiple mechanisms • Dosage: 150mg IV for V-tach, 300mg IV for V-fib arrest • Indications: V-tach, V-fib • Contraindications: allergy, AV block, pregnancy, breastfeeding • Side Effects: lung fibrosis, AV block, Torsades with other QT prolonging medications

29. Paramedic Formulary • Atropine • Effect: antagonizes muscarinic receptors in parasympathetic nervous system • Dosage: 0.5mg-1mg IV • Indication: Symptomatic Bradycardia • Contraindications: none • Side Effects: dry mouth, tachycardia, jitteryness

30. Paramedic Formulary • Hydroxocobalamin • Effect: reverses cyanide toxicity by combining with cyanide to make Vitamin B12 • Dosage:5gm IV • Indications: cyanide Toxicity • Contraindications: caution for hemodialysis patients • Side Effects: none

31. Paramedic Formulary • Tetracaine • Effect: anaesthetizes eye nerve ending through sodium channel blockade • Dosage: 1-2 gtts per eye, repeat PRN • Indications: eye trauma • Contraindications: allergy to agent, open globe • Side Effects: increasing tearing. Burning

32. Paramedic Formulary • Adenosine • Effects: AV nodal blocking agent • Dosage: 0.05-0.1mg/kg up to 6mg IV RAPID push, max 12mg • Indications: SVT • Contraindications: wide complex tachycardia with abberancy, WPW • Side Effect: asystole (short lived), increased HR with WPW.