Pharmacology: Pharmacokinetics: Atropine is readily absorbed from the gastrointestinal tract; it is also absorbed from mucous membranes, the eye, and to some extent through intact skin, it is rapidly cleared from the blood and is distributed throughout the body. It crosses the blood-brain barrier. It is incompletely metabolized in the liver and is excreted in the urine as unchanged drug and metabolites. A half-life of about 4 hours has been reported. Atropine crosses the placenta and traces appear in breast milk. Quaternary ammonium salts of atropine such as the methonitrate, are less readily absorbed after oral doses.