I agree with Sheila. Almost no one here on the board had premeds with Navelbine. My understanding is that it has no benefit in terms of wbc counts. If you want to be really proactive in preventing Vomiting/Nausea, there are non-steroidal alternatives and there seems to be a possibility Dex/Decadron could hamper the chemo:
http://her2support.org/vbulletin/showthread.php?t=41877
You might investigate ways to get the infusion in the evening:
http://jpet.aspetjournals.org/cgi/reprint/289/1/231.pdf
Some hospitals can administer chemo on a hospital floor or in ER for after hour needs.
There may not be any advantage beyond convenience to going to a 2 or 3 week schedule. Plenty of suggestion that less more often has benefits in terms of toxicity/tolerance and often efficacy:
http://her2support.org/vbulletin/showthread.php?t=24729
Hybrid Mode
