DIGITALIS AND YOUMichelle TroendleCase conferenceAugust 6, 2014

Movie #3: Casino Royale!

Casino Royale

Where do you find this in nature?

1) Digitalis purpurea (foxglove) 2) Nereum oleander (oleander) 3) Thevetia peruviana (yellow oleander) 4) Convallaria majalis (lily of the valley) 5) Urginea maritima (red squill) 6) Bufo alvarius (Colorodo River toad)

Digitalis

Purple, pink, white, yellow Grows to about 3 feet Whole plant toxic

Foxglove

Toxin: Digitoxin

Nerium oleander

Common oleander

Toxin: oleandrin

Convallaria majalis

Lily of the valley

Toxin: convallotoxin, convallarin

Thevetia peruviana

Common method of suicide in Sri Lanka Also called Lucky Nut

Yellow oleander

Toxin: thevetin

Urginea maritima

Red squill

Toxin: scillaren

Bufotoxin

Digoxin

Signs of an acute overdose

GI distress – nausea, vomiting, abdominal pain

Lethargy Confusion Atrial and ventricular ectopy (may

progress to VT or VF) Sinus bradycardia Sinus arrest High-degree AV block

Quiz

What is the most common dysrhythmia associated with digoxin toxicity? PVCs

EKG changes – name a pathagnomic dysrhythmia

EKG – another pathagnomic dysrhythmia

When to treat digoxin toxicity

ACUTE CHRONIC

Heart Block K+ > 5 15 ng/mL anytime

after ingestion > 10 ng/mL 6 hrs

after ingestion Ingestion of:

10 mg adult 4 mg child

Dysrhythmia GI symptoms Altered mental status Heart block Hypotension

Dosing of Dig-fab

It blows to calculate 3 general ways to dose:

1) Estimate quantity of digoxin acutely ingested and assume 80% bioavailability

2) Obtain a serum digoxin concentration (SDC) and using a pharmacokinetic formula incorporate the apparent Vd of digoxin using the patient’s body weight (kg)

3) use an empiric dose based on the average requirement for an acute or chronic overdose in an adult or child

Ok let’s go through this – option 1

# of vials = Amount ingested (mg) x 80% .5 (mg/vial)

Limitation – history made be inaccurate, which can cause error in calculating dose

Calculation based on dig level

# vials = SCD (ng/dL) x Weight (kg)100

Empiric

ACUTE CHRONIC

Adults: 10-20 vials Children: 10 vials

*This is a lot easier, but will frequently overestimate or underestimate Fab requirements

Adults: 3-6 vials Children: 1-2 vials

* Each vial of DSFab contains 38 mg (digibind) or 40 mg (digifab) of purified DSFab that will bind approximately .5 mg digoxin or digitoxin

Let’s review this scene

LIKES DISLIKE

Digoxin toxicity can cause ventricular tachycardia

Did they give him digi-fab?

Ipicac – no no no no!!!!!! Patients with ventricular

tachycardia have a heart rate well over 130s

Patients with ventricular tachycardia with a pulse get cardioverted, not defibrillated

Patients generally don’t defibrillate themselves

You do not shock asystole