Back to Articles

Theophylline Protocol

Theophylline Protocol

Theophylline Toxicity Management Protocol

Decontamination

  • Gastric Lavage:
    • If < 1 hour in regular formulation.
    • Up to 6 hours in slow released formulation.
    • No gastric lavage in chronic toxicity.
  • Activated Charcoal:
    • 1gm/kg, then Multiple dose Activated charcoal 0.5-1 gm/kg every 4 hours.
    • (Text note: ?for 24 hours for acute and chronic toxicity).

Stable (Asymptomatic)

Action:

  • History & Examination.
  • In patient & Observe for 12 hours.
  • Check Theophylline blood level.
Outcome:
No clinical manifestations + Zero theophylline blood level
→ Discharge.

Unstable (Symptomatic)

Action: ABCD → Admit to ICU.

Investigations:

  • Theophylline blood level, ABG, electrolytes (K+), glucose, KFT, ECG + Routine investigations.
  • CK, urine analysis (Myoglobinurea) if there is CNS stimulation or hyperthermia.

Appearance of clinical manifestations / Blood Levels:

  • Chronic: > 20 ug/ml
  • Acute: > 40 ug/ml
Goal: Observe & treat Clinical manifestations.
Vomiting
  • Give antiemetics.
  • The preferred antiemetic is ondansetron (high therapeutic doses may be needed).
  • Metoclopramide may be used also.
  • Avoid (Phenothiazine antiemetics).
  • If hematemesis give (H2) blockers or proton pump inhibitors.
Hypotension
  • Give isotonic IV fluid, 0.9% NaCl or lactated Ringer solution, in bolus volumes of 20 mL/kg.
  • If refractory hypotension use β-adrenergic antagonist (propranolol, esmolol, and metoprolol).
  • Use a β-adrenergic antagonist with a brief duration of action, such as esmolol, at least initially.
Treatment of SVT
  • The primary treatment for methylxanthine-induced SVT is benzodiazepines, to decrease CNS stimulation and concomitant release of catecholamines.
  • Administration of Calcium channel blocker such as diltiazem or verapamil.
  • Beta-blockers may be used in patients without asthma.
Convulsions
  • Seizures are difficult to treat, but diazepam and barbiturates are the most effective.
  • Hemodialysis indicated in refractory cases.
  • Avoid phenytoin.
Electrolyte Imbalance

Hypokalemia & hypomagnesemia, hypophosphatemia, hypocalcemia:

  • Potassium supplementation is unnecessary and poorly effective.
  • May be treated with potassium supplementation, according to ECG changes & clinical manifestations.
Hyperglycemia
  • Hyperglycemia does not necessitate treatment, because it is a transient effect and rebound hypoglycemia may occur.
Other (Agitation, Rhabdomyolysis)
  • Agitation: give benzodiazepines (lorazepam) & treat other manifestations.
  • Rhabdomyolysis: IV fluid & sodium bicarbonate.

Hemodialysis Indications

Hemodialysis if:

  • In severe cases not responding to treatment (status epilepticus , dysrhythmias).
  • If the serum level > 80-100 ug/ml in acute toxicity.
  • If the serum level > 60 ug/ml in chronic toxicity.

Discharge Criteria (Symptomatic Patients)

  1. Admit to in patient.
  2. Observe for another 4 hours then do another theophylline blood sample.
  3. Discharge when:
    • Patient is free of clinical manifestations.
    • With decreasing theophylline blood < 10ug/ml.

Avoid / Contraindications

  • Cimetidine: as it inhibits CYP enzymes, delaying theophylline clearance.
  • Phenothiazine antiemetics: are contraindicated because may lower the seizure threshold.
  • Phenytoin: as in treating theophylline-induced convulsions.