Multidose activated charcoal
Background
- Method of enhanced elimination that uses multiple doses of activated charcoal
- No evidence to suggest that MDAC decreases morbidity or mortality
- Some evidence shows that MDAC increases the elimination of certain drugs (further explained below)
- Functions to prevents the absorption of xenobiotics that are slowly absorbed and to enhance the elimination of certain xenobiotics that have already been absorbed
- large amounts of xenobiotics ingested or dissolution is delayed (masses, bezoars)
- formulations that exhibit a delayed or prolonged release phase (enteric coated, extended release)
- GI motility is impaired
- prevent reabsoprtion (enterohepatic circulation of active xenobiotic or metabolite)
Dosing
- 12.5 g/hr in divided doses (eg. 50g Q4hr)
- Should avoid sorbitol-containing formulation in MDAC therapy, as may lead to electrolyte disturbance secondary to diarrhea
Contraindications
- Same as with Single Dose Activated Charcoal (SDAC)
- Intestinal obstruction (absolute)
- Decreased gut motility (relative)
Indications
- Mnemonic: These People Drink Charcoal Quickly
- Theophylline
- Phenobarbital
- Dapsone
- Carbamazepine
- Quinine
- There is also some evidence of utility of MDAC in salicylate overdose
Mechanism of Action
- Stops enterohepatic circulation
- Increases passive diffusion and acts as a sink for the xenobiotics
- Binds drugs in extended release formulations