The intravenous route is not FDA approved and is generally not recommended except when no other alternatives are available. Intravenous administration appears to be associated with a higher risk of QT prolongation and torsade de pointes (TdP) than other forms of administration. The manufacturer recommends ECG monitoring for QT prolongation and arrhythmias if IV administration is required. A dose in the range of 1 to 5 mg IV has been suggested, with the dose being repeated at 30 to 60 minute intervals, if needed. A maximum IV dose has not been established. The lowest effective dose should be used in conjunction with conversion to oral therapy as soon as possible.
PCP has also been shown to cause schizophrenia-like changes in N -acetylaspartate and N -acetylaspartylglutamate levels in the rat brain, which are detectable both in living rats and upon necropsy examination of brain tissue.  It also induces symptoms in humans that mimic schizophrenia.  PCP not only produced symptoms similar to schizophrenia, it also yielded electroencephalogram changes in the thalamocortical pathway (increased delta decreased alpha) and in the hippocampus (increase theta bursts) that were similar to those in schizophrenia.  PCP induced augmentation of dopamine release may link the NMDA and DA hypothesis of schizophrenia. 
processing.... Drugs & Diseases benztropine (Rx) Brand and Other Names: Cogentin