My Husband Has Chronic Pain And Is Now Drinking Quetiapine

My husband has chronic pain and is now drinking quetiapine - 200mg, metoprolol er-50 mg amlodipin besylate 5mg, lyrica 200 mg, cyclopenzapr 10 mg duloxetine 60 mg, gabapentin 800 mg, oxycodone 325 mg, and diazapam 10 mg. He is drinking the oxycodone, gapabentin, lyrica, diazapam and th quetiapine all at once at bedtime. He wakes up still high as a kite, are these medications going to overdose him? I'm so worried now, he hallucinates, talks in his sleep, his speech is slurred and he generally looks bad. Are these medications safe for him to take at once? The others he drinks together two to three times a day. Please help me!