Diphenhydramine Drug Classification
Antihistamine
Diphenhydramine
Benadryl
Diphenhydramine Mechanism of Action
Nonspecific competetive H1/H2 antagonist-blocks histamine release, suppresses central cholinergic activity and inhibits reuptake and storage of DA, leading to prolonged action of DA and reduction of bronchoconstriction, vasodilation, increased vascular permeability
Diphenhydramine Pharmacokinetics
Onset of Action=10-15 min IV, 15-30 min PO
Peak Effects=1-4 hours
Duration of Effect=6-8 hours
Half-Life=1-4 hours
Diphenhydramine Indications/Field Use
Allergic reaction
Anaphylaxis
Dystonic reactions due to phenothiazine administration (EPS)
Diphenhydramine Contraindications
Hypersensitivity
Asthma
Nursing mothers
Diphenhydramine Side Effects/Adverse Reactions
Sedation Dries bronchial secretions Blurred vision Headache Palpitations Dizziness Drowsiness Fatigue Euphoria
Diphenhydramine Dose
Adult: 25-50mg IV, IO, IM, PO
Pedi: 1mg/kg IV, IO, IM, PO max dose 50mg
Diphenhydramine Precautions
Caution with pts with severe liver disease asthma, narrow angle glaucoma, and BPH
May cause hypotension
Diphenhydramine Drug-Drug Interactions
Potentiates sedative effects of alcohol, benzos, narcotics, TCA’s, MAOI’s, furosemide and other anti-HTN’s
Amyl Nitrate Drug Classification
Antidote/ Nitrate Vasodilator
Amyl Nitrate Mechanism of Action
Short acting vasodilator and SMC relaxant that oxidizes hemoglobin to become methemoglobin, which forms a non-toxic complex with cyanide ion to form cyanomethemoglobin, which can be enzymatically degraded
Amyl Nitrate Pharmacokinetics
Onset of Action=10-30 seconds
Peak Effects=30 seconds
Duration of Effect=3-5 minutes
Half-Life=N/A
Amyl Nitrate Indications/ Field Use
Cyanide Poisoning
Amyl Nitrate Contraindications
None
Amyl Nitrate Side Effects/Adverse Reactions
Headache Dizziness Weakness Flushing Cold Sweats Tachycardia Syncope Orthostatic Hypotension N+V
Amyl Nitrate Dose
Adult & Pedi: 0.3mL ampule crushed, inhaled over 15-30sec, q 1 min until sodium nitrate infusion is available
Amyl Nitrate Precautions
May be a medication of abuse, should be stored in secure place with narcotics
Smells like dirty sweaty socks
Ensure pt is sitting prior to administration, hypotension and syncope may be sudden
Amyl Nitrate Drug-Drug Interactions
Hypotension potentiated by antihypertensives, B blockers, and certain antiemetics (phenothiazines)
Activated Charcoal
Actidose, Liqui-Char
Activated Charcoal Drug Classification
Antidote
Activated Charcoal Mechanism of Action
Liquid suspension binds (absorbs) toxic substances, thereby inhibiting their GI absorption, enterohepatic circulation, and bioavailability.
Drug charcoal complex is then excreted by the body
Activated Charcoal Pharmacokinetics
Onset of Action=Immediate
Peak Effects=Unknown
Duration of Effect=Unknown
Half-Life=Unknown
Activated Charcoal Indications/Field Use
Acute toxic ingestion
Activated Charcoal Contraindications
Ingestion of caustic or petroleum based agent (mineral acid, caustic alkali, organic solvent, iron, methanol, ethanol)
Poisoning by cyanide
Activated Charcoal Side Effects/Adverse Reactions
Vomiting Diahrrhea Abdominal cramping Bloating Constipation Black/Tarry stool for several days
Activated Charcoal Dose
Adult: 1g/kg (30-100g) PO
Pedi: 1-2g/kg PO
Activated Charcoal Precautions
Best if given within 30 minutes of overdose
Administer PO to conscious pt only, if pt is comatose or intubated, administer through NG tube
Activated Charcoal Drug-Drug Interactions
Food or other medications administered concurrently will decrease absorptive capacity of charcoal
Albuterol Sulfate
Proventil HFA, ProAir HFA
Albuterol Sulfate Drug Classification
Sympathomimetic/ Sympathetic agonist (B2 selective)
Albuterol Sulfate Mechanism of Action
B2 agonist - bronchodilation
Albuterol Sulfate Pharmacokinetics
Onset of Action=5-15 minutes
Peak Effects=1-1.5 hours
Duration of Effect=3-6 hours
Half-Life=<3 hours
Albuterol Sulfate Indications/Field Use
Asthma
Reversible bronchospasm associated with COPD
Albuterol Sulfate Contraindications
Symptomatic tachycardia
pts with history of hypersensitivity
Albuterol Sulfate Side Effects/Adverse Reactions
Anxiety Headache Palpitations Sweating Dizziness Nervousness Tremor HTN Arrhythmia Chest Pain N+V
Albuterol Sulfate Dose
Adult MDI: 1-2 sprays (90mcg/spray)
Adult & Pedi Neb: 2.5mg in 2.5mL of NS over 5-15 min
Albuterol Sulfate Precautions
BP, pulse, and EKG should be monitored
use caution with pts with known heart disease or HTN
auscultate LS before and after
Albuterol Sulfate Drug-Drug Interactions
SE may increase with other sympathetic agonists
B blockers may blunt effects of this drug
Epinephrine
Adrenalin, EpiPen, EpiPen Jr.
Epinephrine Drug Classification
Sympathomimetic/Sympathetic agonist/Catecholamine
Epinephrine Mechanism of Action
Alpha 1 agonist: peripheral vasoconstriction, increases SVR and BP
Beta 1 agonist: positive inotropy, chronotropy, dromotropy
Beta 2 agonist: bronchodilation
Blocks destruction of MAST cells (which release Histamine) in anaphylaxis
Epinephrine Pharmacokinetics
Onset of Action=<5 min IV, 20 min IM
Duration of Effect=5-10 min IV, 20-30 min IM
Half-Life=5 min IV
Epinephrine Indications/Field Use
Cardiac arrest
Anaphylaxis/Severe reactive airway disease
Symptomatic bradycardia/hypotension
Epinephrine Contraindications
HTN and tachydysrhythmias
use caution with pregnancy and CAD
Epinephrine Side Effects/Adverse Reactions
Anxiety, HA, dysrhythmias, tremulousness, dizziness, N+V, leads to increased myocardial O2 demand
Epinephrine Dose
Cardiac arrest (Adult): 0.5-1mg IV, IO 1:10,000 q 3-5 min
Bradycardia/Hypotension (Adult): 2-10mcg/min
Anaphylaxis/Asthma (Adult): 0.3-0.5mg IM, SC 1:1,000 then 0.1mg 1:10,000 slow IV, IO over 3 min
Cardiac arrest (Pedi): 0.01mg/kg IV, IO 1:10,000 q 3-5min Anaphylaxis/Asthma (Pedi): 0.01mg/kg IM, SC 1:1,000, then 0.01 mg/kg slow IV, IO 1:10,000; max dose 0.3mg
Epinephrine Precautions
Should be protected from light
Epinephrine Drug-Drug Interactions
pH dependent, deactivated by alkaline solutions
effect intensified with pts taking antidepressants
react with CaCl2 and NaHCOe to form PPT in IV tubing
Methylprednisolone
Solu-Medrol
Methylprednisolone Drug Classification
Corticosteroid/Anti-inflammatory
Methylprednisolone Mechanism of Action
Diffuses across cell membrane, binds to DNA, regulates gene expression and increases synthesis of proteins and enzymes that inhibit inflammatory agents (cytokines, interleukin, interferon); inhibits synthesis of pro-inflammatory enzymes. Is an immunosuppressant
Methylprednisolone Pharmacokinetics
Onset of Action=2-6 hours
Peak Effects=4-8 days
Duration of Effect=1-5 weeks
Half-Life=3.5 hours
Methylprednisolone Indications/Field Use
Severe anaphylaxis, hives
Asthma, COPD
Spinal cord injury
Methylprednisolone Contraindications
None EMS
Methylprednisolone Side Effects/Adverse Reactions
Fluid Retention, CHF, HTN, Abdominal distension, Vertigo, HA, Nausea, Malaise, Hiccups
Methylprednisolone Dose
Asthma/Anaphylaxis (Adult): 125-250 IV, IO
Spinal Cord Injury (Adult): 30mg/kg IV, IO over 15 min, maintenance 5.4mg/kg/hr for 24-48 hours
Asthma/Anaphylaxis (Pedi): 2mg/kg IV, IO, IM; mag dose 80 mg
Methylprednisolone Precautions
Give only one dose prehospitally
LT steroid use can cause GI bleeding
Prolonged wound healing
Suppression of adrenocortical steroids
Methylprednisolone Drug-Drug Interactions
Lasix and thiazide diuretics increase potassium loss
Decreased effect with phenytoin, phenobarbital, and rifampin due to increased metabolism of steroids