How to know what is better, a pharmacist or an emergency medicine physician?

Problem? Er doctors are physicians trained in diagnosing and treating patients. Pharmacists are experts in the administration of medicine. Both work in conjunction to help the patient. What are your needs?
Loaded question- I'll interpret this question as - who is better to answer detailed questions about a prescribed drug during a busy period in the ed? Better to go through and check drug-drug interactions with the patient , explaining why each interaction occurs? Better in verifying what medication is covered by an insurance plan? To all these questions, it's the pharmacist- not the overworked ed physician.