Idaho State University Paramedic Program - Pharmacology Profiles

Vocabulary flashcards covering mechanisms of action, indications, contraindications, dosages, and kinetics for ten emergency medications from the Idaho State University Paramedic Program profile.

Promethazine (Phenergan)

A phenothiazine antiemetic and antihistamine that blocks $H_1$ receptors peripherally and serotonin in the chemoreceptor trigger zone to provide antiemetic and antihistaminic actions.

Promethazine Indications

Indicated for nausea and vomiting, allergic reactions (not first-line), urticaria, vertigo, and sedation (not first-line).

Promethazine Contraindications

Hypersensitivity, subcutaneous (SQ) injection, GI/GU obstruction, severe CNS depression/coma, and age $< 2\,\text{years}$.

Promethazine Dosing and Administration

Adult: $12.5-25\,\text{mg}$ slow IVP or deep IM. Pediatric ($> 2\,\text{years}$): $0.5-1\,\text{mg/kg}$ slow IVP or deep IM (use extreme caution). Supplied as $25\,\text{mg/mL}$ or $50\,\text{mg/mL}$.

Promethazine Kinetics and Adverse Effects

IV onset is $3-5\,\text{min}$, IM onset is $\sim 20\,\text{min}$, and duration is $4-6\,\text{hr}$. Potentiates CNS depressants, lowers the seizure threshold, and may cause severe tissue necrosis, somnolence, disorientation, hypotension, tinnitus, tachy/bradycardia, and EPS.

Ipratropium Bromide (Atrovent)

An anticholinergic bronchodilator that blocks muscarinic cholinergic receptors, decreasing smooth-muscle contraction, causing bronchodilation, potentiating $\beta_2$ medications, and inhibiting nasal/bronchial secretions.

Ipratropium Bromide Indications and Contraindications

Indicated for bronchospasm refractory to, or treated with, $\beta_2$ agonists. Contraindicated in closed-angle glaucoma and atropine sensitivity (older peanut/soy warning no longer applies to reformulated product).

Ipratropium Bromide Dosing and Kinetics

Adult: $0.5\,\text{mg}$ (profile lists every $6-8\,\text{hr}$). Pediatric ($5-14\,\text{years}$): $0.25-0.5\,\text{mg}$ every $20\,\text{min} \times 3$ PRN. Prepared as MDI or $0.02\%$ inhalation solution ($0.5\,\text{mg} / 3\,\text{mL}$). Initial response is $15-30\,\text{min}$, peak is $1-2\,\text{hr}$, and duration is $4-5\,\text{hr}$.

Vecuronium (Norcuron)

A non-depolarizing neuromuscular blocker that antagonizes acetylcholine at the motor end plate to produce skeletal-muscle paralysis; does NOT provide sedation, analgesia, or amnesia.

Vecuronium Indications and Contraindications

Indicated to maintain paralysis after RSI and facilitate ETT when succinylcholine is contraindicated or prolonged paralysis is needed. Contraindicated in known bromide sensitivity; use caution with heart disease or urticaria.

Vecuronium Dosing

Induction: $0.1\,\text{mg/kg}$ slow IVP. Maintenance: $0.01\,\text{mg/kg}$ slow IVP. Defasciculation: $0.01\,\text{mg/kg}$. Pediatric dose matches the adult profile. Supplied as a $10\,\text{mg}$ powder vial reconstituted with $10\,\text{mL}$ saline for IV/IO administration.

Vecuronium Kinetics and Drug Interactions

Onset is $1-3\,\text{min}$, peak is $3-5\,\text{min}$, and duration is $\sim 25-40\,\text{min}$. Potentiated by beta-blockers, $MgSO_4$, opiates, procainamide, and lidocaine.

Ondansetron (Zofran)

An antiemetic and selective serotonin ($5\text{-}HT_3$) antagonist that blocks $5\text{-}HT_3$ receptors on vagal terminals and centrally in the chemoreceptor trigger zone to prevent and treat nausea and vomiting.

Ondansetron Dosing and Administration

Adult: $4\,\text{mg}$ slow IVP or IM; may repeat once. Pediatric ($> 2\,\text{years}$): $0.15\,\text{mg/kg}$ slow IVP or IM; may repeat once. Supplied as vial/PFS of $4\,\text{mg} / 2\,\text{mL}$ and administered over $2-3\,\text{min}$.

Ondansetron Kinetics and Adverse Effects

Peak occurs in $< 5\,\text{min}$ with a duration of $4-12\,\text{hr}$. Side effects include anxiety, somnolence, hypotension, headache/dizziness, chest pain, and tachycardia. Toxicity is rare, but CNS depression or excitability may occur.

Magnesium Sulfate

An electrolyte/cation and antiarrhythmic that acts at multiple sites, including calcium channels and neuromuscular transmission, to stabilize membranes, reduce neuronal excitability, and promote smooth-muscle relaxation.

Magnesium Sulfate Indications and Contraindications

Indicated for torsades/long QT, refractory VF/VT, eclampsia/preeclampsia, refractory bronchospasm, and hypomagnesemia. Contraindicated in bradycardia, heart blocks, hypermagnesemia, and multiple births per course profile.

Magnesium Sulfate Dosing

Torsades/VF/VT: $1-2\,\text{g}$ over $2\,\text{min}$, repeated every $3-5\,\text{min}$. Eclampsia: $2-4\,\text{g}$ over $2-5\,\text{min}$. Preeclampsia: $2-4\,\text{g}$ over $20-30\,\text{min}$. Bronchospasm: $2\,\text{g}$ over $2-5\,\text{min}$.

Magnesium Sulfate Administration Notes

Supplied as PFS/vials of $5\,\text{g} / 10\,\text{mL}$. Usually do not exceed $1\,\text{g/min}$ to avoid hypotension. Chemically incompatible with sodium bicarbonate.

Rocuronium (Zemuron)

A non-depolarizing neuromuscular blocker that competitively binds cholinergic receptors at the motor end plate, blocking acetylcholine to produce paralysis; does NOT provide sedation or analgesia.

Rocuronium Indications and Contraindications

Indicated to maintain paralysis after RSI or induce paralysis for intubation when succinylcholine is contraindicated. Contraindicated in hypersensitivity to bromides.

Rocuronium Dosing and Kinetics

Adult induction: $1\,\text{mg/kg}$ IV. Defasciculation: $0.02-0.04\,\text{mg/kg}$ ($0.04\,\text{mg/kg}$ is listed as optimal). Pediatric: $1\,\text{mg/kg}$. Supplied as $100\,\text{mg} / 10\,\text{mL} = 10\,\text{mg/mL}$. Peak action is $1-2\,\text{min}$.

Ketamine (Ketalar)

A dissociative anesthetic and NMDA receptor antagonist that blocks cortical/limbic NMDA receptors (and acts on mu-opioid receptors at high doses) to produce dissociation with amnesia, sedation, analgesia, and anesthesia.

Ketamine Indications and Contraindications

Indicated as an RSI/DAI adjunct, sedation during mechanical CPR, pain control, and chemical sedation. Contraindications are all relative in course profile: hypertensive emergencies, sympathomimetic intoxication, increased IOP, schizophrenia, or situations where increased BP may be harmful.

Ketamine Dosing and Administration

Adult RSI/DAI/restraint: $1-2\,\text{mg/kg}$ slow IVP; Adult pain: $0.2-0.5\,\text{mg/kg}$. Pediatric RSI/restraint: $2\,\text{mg/kg}$; Pediatric pain ($> 1\,\text{year}$): $0.2-0.5\,\text{mg/kg}$. Supplied as $200\,\text{mg} / 20\,\text{mL}$ or $500\,\text{mg} / 10\,\text{mL}$. Rapid IV push increases risk of respiratory depression.

Etomidate (Amidate)

A hypnotic and anesthesia-induction agent that appears to enhance/mimic GABA activity in the reticular activating system, depressing consciousness to produce rapid hypnosis without analgesic properties.

Etomidate Indications and Contraindications

Indicated as an adjunct to facilitate ETT and conscious sedation for synchronized cardioversion. Contraindicated in known hypersensitivity, pediatric age $< 1\,\text{year}$, and active labor.

Etomidate Dosing and Kinetics

Adult ETT: $0.3\,\text{mg/kg}$ (profile notes max may be $20-30\,\text{mg}$); Cardioversion: $0.15\,\text{mg/kg}$; Pediatric ($> 1\,\text{year}$): $0.15\,\text{mg/kg}$. Supplied as $40\,\text{mg} / 20\,\text{mL}$ or $20\,\text{mg} / 10\,\text{mL}$. Onset is $\sim 1\,\text{min}$, duration is $3-5\,\text{min}$, and recovery is $< 10\,\text{min}$.

Succinylcholine (Anectine)

A depolarizing neuromuscular blocker that binds ACh receptors and depolarizes skeletal muscle; persistent binding prevents further depolarization, causing rapid flaccid paralysis with initial fasciculations without providing sedation, analgesia, or amnesia.

Succinylcholine Contraindications

Hyperkalemia, crush/trauma $> 5\,\text{days}$, burns $> 8\,\text{hr}$, pseudocholinesterase deficiency, history of malignant hyperthermia, chronic abdominal infection/sepsis, penetrating eye injury, and narrow-angle glaucoma.

Succinylcholine Dosing and Kinetics

Adult: $1-2\,\text{mg/kg}$ rapid IVP (common start $1.5\,\text{mg/kg}$); Pediatric: $2\,\text{mg/kg}$. Supplied as $200\,\text{mg} / 10\,\text{mL} = 20\,\text{mg/mL}$. IV onset is $30-60\,\text{sec}$ and duration is $3-5\,\text{min}$. Must wait until fasciculations end for full effect; repeat doses can cause bradycardia.

Oxytocin (Pitocin; Syntocinon)

A uterine stimulant hormone that increases intracellular calcium in uterine smooth muscle to stimulate uterine contractions and enhance lactation; primarily indicated to control postpartum bleeding.

Oxytocin Contraindications

Contraindicated before delivery of the placenta or all fetuses in a multiple birth, cephalopelvic disproportion, fetal distress without imminent delivery, and hyperactive or hypotonic uterus.

Oxytocin Dosing and Complications

Postpartum bleeding: $10\,\text{units}$ IM preferred, OR $10-40\,\text{units}$ in $250-1000\,\text{mL}$ over $15\,\text{min}$. Supplied as $10\,\text{units/mL}$. Peak is $1-6\,\text{min}$, and duration is $\sim 30\,\text{min}$ IV to $2.5\,\text{hr}$ IM. Prolonged administration can cause water intoxication, seizures, and coma.