Patients who receive Ativan Injection as a premedicant should be cautioned that driving a motor vehicle, operating machinery, or engaging in hazardous or other activities requiring attention and coordination, should be delayed for 24 to 48 hours following the injection or until the effects of the drug, such as drowsiness, have subsided, whichever is longer. Sedatives, tranquilizers and narcotic analgesics may produce a more prolonged and profound effect when administered along with injectable Ativan. This effect may take the form of excessive sleepiness or drowsiness and, on rare occasions, interfere with recall and recognition of events of the day of surgery and the day after.
Haloperidol is a typical butyrophenone type antipsychotic that exhibits high affinity dopamine D 2 receptor antagonism and slow receptor dissociation kinetics.  It has effects similar to the phenothiazines .  The drug binds preferentially to D 2 and α 1 receptors at low dose (ED 50 = and mg/kg, respectively), and 5-HT 2 receptors at a higher dose (ED 50 = mg/kg). Given that antagonism of D 2 receptors is more beneficial on the positive symptoms of schizophrenia and antagonism of 5-HT 2 receptors on the negative symptoms, this characteristic underlies haloperidol's greater effect on delusions, hallucinations and other manifestations of psychosis.  Haloperidol's negligible affinity for histamine H 1 receptors and muscarinic M 1 acetylcholine receptors yields an antipsychotic with a lower incidence of sedation, weight gain, and orthostatic hypotension though having higher rates of treatment emergent extrapyramidal symptoms .
Anti-Parkinson Agents (Dopamine Agonist): May diminish the therapeutic effect of Antipsychotic Agents (First Generation [Typical]). Antipsychotic Agents (First Generation [Typical]) may diminish the therapeutic effect of Anti-Parkinson Agents (Dopamine Agonist). Management: Avoid concomitant therapy if possible and monitor for decreased effects of both agents when these combinations cannot be avoided. Atypical antipsychotics such as clozapine and quetiapine may be less likely to reduce the effects of anti-Parkinson agents. Consider therapy modification