Diplomacy and communication. Nurses will drive pharmacists nuts, but keep the DON/nurse manager on your side. Their turn over is much higher than pharmacy and have it worse. I went through 4 DONs, 3 nurse managers in the last 4 years. Each time I offered help to make their lives easier (help orientation them, help with heir reports, lend them a shoulder when they got beaten up by corporate..) At leadership level, we face similar pressures and issue with staffs, talk and help each other against those has worked for me.
And work hard in a way that shows. CEOs get their butts chewed when their numbers look bad. Again, help them with results. I drove the drug cost down by looking for inefficiencies, auto subs, antibiotic stewardship... Cut agency and overtime cost by hiring PRNs and filling in gaps myself. Work hard to get those results and communicate to the CEOs know how they are getting those good numbers, and they will want to keep and protect you.
Approach physicians humbly and build that relationship. Offer to be their eyes and ears, catch a few things they might have missed and let them know discreetly. Do your research before hand so they know you know what you are talking about... Soon they'll see you as their helper. Choose your battles on drugs. Often its betting to let go some cheaper non-formulary drugs to save up that political clot to ask for a pass on a big budget buster.
There a ton more that go into working in a complex organization. And you don't have to get it all right. I have gotten into trouble couple of times, but got enough right to stayed on the good-list.