(Theophylline and Caffeine)
All are structurally similar to adenosine. They exert their effects by competitively inhibiting adenosine binding in the CNS where adenosine would allow increased GABA channel flow and peripherally where adenosine is a vasodilator. At high doses, they may act as a phosphodiesterase inhibitor
Theophylline levels will increase with smoking cessation.
Caffeine overdoses are often from OTC alertness meds (NoDoz) and migraine meds
Therapeutic levels of caffeine and theophylline are 5 to 15 ug/ml
>20 is toxic range in patients without prior exposure
Presents with abdominal pain and n/v with any significant dose
sinus tachycardia or MAT, can progress to AMI or v. tach
vasodilation
agitation, nervousness, headache, seizures
hypokalemia and hyperglycemia
hyperthermia
Widened pulse pressure, vasodilation leads to decreased diastolic, inotropy leads to increased systolic
Theophylline levels Q2
Lavage if sustained release
AC for immediate absorption and gut dialysis. 1-2 grams/kg Q2 hrs to 7 doses
Consider whole bowel irrigation along with charcoal
Fluids
For SVT diltiazem or esmolol
Phenylephrine or Norepi
Vent dysrhythmias give lidocaine and consider b-blockade
Seizures-benzos
Consider Charcoal Hemoperfusion/HD if
Theo level >40 with seizures, hypotension, vent dysrhythmias, or protracted vomiting
Theo level >90 acute or >60 chronic
Of note, adenosine will not work with theo on board, probably wont work with a few cups of coffee on board either
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