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EMERGENCY PHARMACOLOGY JUST SAY “KNOW” TO DRUGS

Dr. Caleb Frankel

Emergency and Critical Care Service

September 2013

“Today’s veterinary technician is a professional, and such, has the responsibility to understand thereasons and the expected outcomes for the treatments they perform. Today’s veterinary technician ismore than a skilled set of hands. Today’s veterinary technician must know how to critically evaluate,problem solve, think, and adapt to their patient’s needs.”

WHY PHARMACOLOGY FOR NURSES?

“Today’s veterinary technician is a professional, and

such, has the responsibility to understand the reasons and the expected outcomes for the treatments they perform.

Today’s veterinary technician is more than a skilled set of hands.

Today’s veterinary technician must know how to critically evaluate, problem solve, think, and adapt to their patient’s needs.”

- Peter Bill, DVM 2010AACVM Meeting Washington DC

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WHAT YOU WILL LEARN

1. Drug Background Info

2. ER Drug Survival Guide Crash Cart & CPR Drugs

Anti-Seizure Drugs

Cardiopulmonary Drugs

Sedation and Pain Management Drugs

GI Drugs

Toxin Antidotes

3. Medication Math (made easy)

4. Drug That Don’t Play Nice

5. Reliable Resources

MEDICATIONS BACKGROUND

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History of Drugs and Medicine

FACT: 99% of drugs used today were developed in the past 60 years!

A Brief 4000 Year History of Medicine

2000 B.C.—Here, eat this root.

1000 A.D.—That root is heathen. Here, say this prayer.

1850 A.D.—That prayer is superstition. Here, drink this potion.

1920 A.D.—That potion is snake oil. Here, swallow this pill.

1945 A.D.—That pill is ineffective. Here, take this penicillin.

1955 A.D.—Oops . . . bugs mutated. Here, take this tetracycline.

1960–1999—39 more “oops.” Here, take this more powerful antibiotic.

2010 A.D.—That antibiotic is artificial! Here, eat this root.

—Anonymous

Important Definitions

Drug vs. Poison

Pharmacology vs. Pharmacokinetics

Dose vs. Dosage

Concentration

Half Life (t ½)

Generic vs. Trade (Brand) Name…

COMMON DRUG ABBREVIATIONS

- CRI = Continuous rate infusion- IV = Intravenous- IM = Intramuscular- SQ (SC) = Subcutaneous- PO = Per “os” or by mouth- PR = Per rectum

- OU = Both eyes- OD = Right eye- OS = Left eye- AU = Both ears- AD = Right ear- AS = Left ear

- PRN = as needed- cc = mL- SID = once daily (q24h / qd)- BID = twice daily- TID = three times daily (q8h)- QID = four times daily (q6h)- EOD = every other day (qod)

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Drug name: Famotidine

(Brand name: Pepcid)

Concentration (10mg/mL)

The Bottle

Drug Basics (nerd stuff)

Absorption

Distribution

Drug Clearance

Hepatic Metabolism Biliary Excretion Renal Excretion

Lipid vs. Water Soluble

First Pass Effect

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Controlled Drugs (DEA Schedules I – V)

Prescribing Legally (V-C-P-R)

Veterinarians Acting as “Pharmacies”

US’s 1994 AMDUCA (Extra-label use)

Drugs and The Law

EMERGENCY DRUG SURVIVAL GUIDE

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VETERINARY CPR IS COOL

AGAIN

CRASH CART DRUGS

Epinephrine Vasopressin Atropine

Lidocaine Amiodarone Calcium

Gluconate

Insulin

(regular)

Dextrose REVERSAL AGENTS

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CPR TREATMENT CHOICE?

CORESPBP2BP1

E

C

G

E

T

C

O

2

210

CORESPBP2BP1

E

C

G

E

T

C

O

2

- - -

Epinephrine Vasopressin Atropine

FIRST LINE CPR DRUGS

Class: catecholamine

Uses: CPR (why?)

Action: constricts peripheral vessels (good) and speeds heart (bad)

Also for anaphylaxis and hemorrhage topically

Dose: low vs. high

Class: Hormone (ADH)

Uses: CPR (why?)

Action: Constricts peripheral vessels without heart effects

Also for Diabetes Insipidus, and VWD

Works in acidic pH?

Class: Anticholinergic

Really cool history

Uses: CPR (why?)

Action: inhibits slow down signals to heart. “vagolytic”

Also for bradycardia and for insecticide and nerve agent (OPs) toxicity

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REVERSAL AGENTS

DON’T FORGET THESE IN ANESTHETIC OR POST-ANESTHETIC ARRESTS!

Naloxone Flumazenil Atipamezole Yohimbine

OTHER CPR DRUGS

Class: antiarrhythmic

Uses: Ventricular tachycardia

Also for local anesthesia

Controversial in CPR –suppresses heart and can make defibrillation unsuccessful

Amiodarone = best for shock-resistant V-tach or v-fib? (controversial)

Lidocaine Amiodarone

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THE DYING BLOCKED CAT TRIFECTA

Calcium

Gluconate

Insulin

(regular)

Dextrose

The Problem?

What is the treatment?

Which catheter first? IVC or urinary?

How does Ca gluconate work?

How do insulin and dextrose work?

Dextrose = never give 50% peripherally or SQ

Other ER uses for these 3: Ca: Hypocalcemia, Addisonian crisis, Ca-channel

blocker overdose Insulin: Addisonian crisis, DKA/diabetes Dextrose: hypoglycemia!

THE CONTROVERSIAL CRASH CART

Doxapram

Dexamethasone (steroids)

A very important ER drug!

Indications: Anaphylaxis/allergy, asthma or life-threatening airway swelling (larpar, trach collapse), Addisonian crisis, immune disease, some cerebral edemas

Not routinely used: shock / CPR

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SEIZURE DRUGS

Diazepam Propofol Phenobarbital(Keppra)

Class: benzodiazepine

Also: sedative, anxiolytic, muscle relaxant

Works as GABA agonist

Paradoxical reactions

IV only – Quick dose

Class: anesthetic

Also: emergency intubation, anesthesia

Works via ??

RESPIRATORY ARREST (Michael Jackson). Hypotension

IV only

Class: Barbiturate

Also: sialadenosis

Works centrally to inhibit various chemicals - depressant

Very sedating for first 1-2 weeks after starting. Hepatotoxic.

IV only – very irritating otherwise

Mannitol

CARDIO / RESPIRATORY DRUGS

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MY. WORST. NIGHTMARE.

FELINE ASTHMA TOOLBOX

Terbutaline Dexamethasone SP

Albuterol

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CONGESTIVE HEART FAILURE (simple)

Furosemide (Lasix) Nitroprusside

Reduce resistance pumping into (vasodilator)

Reduces amount of fluid to pump (diuretic)

ER PAIN KILLERS

Butorphanol Buprenorphine

Hydromorphone

Morphine

Methadone

FentanylButorphanol

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MY FAVORITE ER PAIN KILLERS

The “Ideal” Pain Killer

Works fast Powerful Minimal sedation No side effects Reversible Not controlled

SOME HIGHLIGHTS REVERSIBLE! (how?)

Hydromorphone – cheap, fast, reversible. (Sedating, Panting +/- Vomiting)

Methadone – hydro plus NMDA blocker without side effects! (Expensive)

Fentanyl – short acting, potent (need CRI, respiratory depression). Patches?

DEA Schedule 2 Drugs

ER SEDATIONAcepromazine Butorphanol Propofol

ER Uses: laryngeal paralysis, tracheal collapse, respiratory distress, heat stroke

Also: antihistamine, antiemetic, hypothermic

Drops blood pressure and takes full 30-60 minutes until onset!

ER Uses: Respiratory emergencies, mild-moderate sedation for diagnostics, anti-anxiety

Generally safe with minimal side effects

Mild pain reliever but only for 30 minutes!

ER Uses: emergency intubation, short anesthesia, seizures

Never forget respiratory arrest (I intubate most animals on propofol)

Dexmedetomidine

ER Uses: short ER procedures, pain control!

Only for otherwise healthy animals

Causes very low heart rates! (How to treat?)

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COMMON GI MEDICATIONS

(Pepcid) (Protonix)

Sucralfate (Carafate)

(Prilosec)

Pepcid / Tagamet / Zantac Block histamine receptor on the stomach

acid producing pump Pepcid = most effective in pets and least

side effects Zantac sometimes used in constipated cats

Protonix / Prilosec / Nexium Blocks proton pump Takes some time to work

Stomach ulcer coater

COMMON GI MEDICATIONS

(Zofran) (Reglan)Maropitant

Metronidazole (Flagyl)

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TOXICITY TIME

DECONTAMINATION (VOMITING)Hydrogen Peroxide Apomorphine Xylazine

How does is work? Local irritant to mucosa

Dose: 1-5 mL/kg (Max Dog = 50mL, Max Cat = 10 mL)

Not my favorite (I try to avoid in this day and age)

The emetic of choice in dogs (why?)

Generally safe with minimal side effects

Comes in eye drop or injectable solution (most effective).

Emetic of choice in cats (why?)

Very sedating

Not reliable but the best we know.

Reversible? Yohimbine

When NOT to induce vomiting?

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ACTIVATED CHACOAL

What is it?

Must come in contact with toxin to work

Which toxins? “-ol” rule

Many formulations

Risks?

ANIMAL POISON RX

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MEDICATION MATH (MADE EASY)

Pharmacology Math Toolbox

MATH PROBLEM SOLUTION NOTES

POUNDS VS. KILOGRAMS 2.2 Pounds = 1 kilogram (kg) Every 22 pounds = 10kg

DRUG PERCENTAGES 1% = 10mg/mLJust move the decimal 1 place to right

LIQUID DRUG DOSESMG drug = WEIGHT KG x dose (mg/kg)ML drug = MG ÷ mg/mL on bottle

Exa: dr asks for 6mg/kg and 10kg dog. Drug is 15mg/mLAnswer = 4mL

IVF ADDITIVESDosed in mg/L, mEq/L or %Solve for mL

If not exactly 1 liter left, set up a ratio and cross multiply

FLUID PUMP BOLUSESGiven: mL desired over certain time

𝑹𝒂𝒕𝒆 = 𝒎𝑳 𝒙 (𝟔𝟎

𝒕𝒊𝒎𝒆 𝒊𝒏 𝒎𝒊𝒏𝒔)

Set VTBI as mL given by doctorSet Rate as what you calculated

CRI CALCULATIONS

𝑲𝑮 ∗ 𝑫 ∗ 𝑭

𝑰𝑽𝑭 𝒓𝒂𝒕𝒆= 𝑴𝒈

D = Dose in ug/kg/minF = Fluid factor (0.06 x every 1 mL fluid) IVF rate = ml/hr

Mg = mg to add to bag of fluids

Lots of ways to calculate CRIs–ultimately need to know dose and fluid rate to start and need to come up with mg to add to fluid.

For CRI doses, know that :1mg/kg/hr = 16.7ug/kg/min

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QUICK DOSING SECRETS

Valium, Lidocaine, Naloxone, Flumazenil

Dextrose in IVF Bags

Calcium Gluconate

Shock IVF Boluses

COMMON DRUG

REACTIONS

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INTERACTIONS TO KNOW

DRUG(S) INFORMATION

SucralfateBinds drugs decreasing absorption (esp

Fluroquinolones antibiotics – Baytril). Timing!

Tramadol + Mirtazipine Serotonin syndrome!

Phenobarbital

Increases liver metabolism of some drugs. Thus,

decreases the action of many drugs (theophylline,

lidocaine, valium, tramadol). Only seen in dogs.

Omeprazole &

Cimetidine

Decreases liver metabolism of some drugs. Thus

increases toxicity of tramadol, diazepam,

lidocaine, theophylline. Clopidogrel (Plavix) can’t e

activated (won’t work).

Substitute for pantoprazole and Pepcid.

FDA’s veterinary drug reaction hotline: 1-888-FDA-VETS

INTERACTIONS TO KNOW

DRUG(S) INFORMATION

Furosemide + DigoxinBoth are used for heart failure but furosemide

causes increased digoxin levels.

Furosemide +

Lidocaine

Lidocaine doesn’t work well if there is

hypokalemia (low K) and furosemide lowers K.

These also don’t mix well with others in IV line.

Reglan + DopamineReglan is a dopamine blocker. Kidney effects from

dopamine are not affected.

Fluroquinolones +

TheophyllineIncreases theophylline to possibly toxic levels.

Butorphanol Antagonizes other opiate pain killers.

More resources (IVF interactions, etc) online…

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RELIABLE DRUG RESOURCES

Drug Package Inserts

Plumb’s VDH (7th)

Trissel Handbook on Injectable Drugs

Other Textbooks

Apps / Calculators / Online Resources:

www.vmdtechnology.com

QUESTIONS?

drfrankel@vmdtechnology.com

LECTURE GOODIES: www.vmdtechnology.com/er-pharma-9122013 | Password = VSEC