In the ICU, many times physicians will write orders to titrate Propofol as needed (at least they did when I worked in ICU). So technically, this could be considered a titration to maintain level of sedation during uncomfortable/difficult procedures on patients.
Tysabri is an interesting medication. We have given the infusions for quite some time. The rep should give you plenty of information about the drug and infusion requirements. It is typically infused over an hour, and we do vitals every 30 minutes We observe the patient 1 hour post infusion (letting 100 mL NS infuse during observation time). PML is major concern with this drug.