Vomiting, hasn't eaten in 36 hours, Doxepin od?....

That could be from the overdosing, given the shaking and the vomiting. I would make a visit to the vet very soon. Just make sure she stays hydrated, does she eat dry food? Try putting a bit of water in it, or make her some lean ground beef with rice and give her just a bit.. Good luck, that is very scary!

I'd call the vet or the emergency vet right away and explain what happened and how much she took.  You didn't mention her size but if she's a small dog this could definately be from that.  It could also be totally unrelated to the pills but I'd call and see what they say.  You don't want this to be effecting her internally (if it is the pills) for the next 24 hours or so.  It might do some damage. 

Yeah, I would call someone,,,a vet or emergency or even poison control at
1-800-548-2423 or 1-900-680-0000.
They may charge you but it might be worth it. 

I just called the ASPCA toxicology dept. and they dont think it's from an overdose so I'm going to try and take her to the vet now. Keep your fingers crossed.
 

Fingers crossed, good luck, let us know! 

Good luck, will be praying!

hope your dog be ok *fingers crossed*

Sure WILL keep our fingers AND paws crossed! Please let us know when you get back!

Finally came back from the emergency clinic. Turns out Hap has  pancreatitis and will need to stay overnight and probably tomorrow night as well, but should be ok. I just read online that steroids and a high-fat diet can be causes and Hap is on both so I'll have to talk about that with my vet. Thanks again for the well wishes. Me and Hap appreciate it!
 
Oh yeah, forgot to mention earlier, she's a 60-lb pit bull.

I'm glad she is being taken care of,,,I'm sure you are too!  
Yeah, I guess you will need to change her food and medications.
Our Dane Ollie went thru a few years of allergies,,,scratching, bumps on his skin, staph infections,,then stomach infections. He was on antibiotics a lot and steriods here and there. We finally realized these drugs were helping him only while he was on them, and then it would come back. The time NOT on drugs was getting shorter and shorter.  We changed his diet to premium food...and took him to a skin specialist..got him off of drugs. He was blood tested for allergies and found to be allergic to grass and dust,,,two things we can do NOTHING about.   He was given weekly allergen shots, he eats Eagle Pack food and doesn't get vaccinations anymore,,,we believe he has a weakened immune system from them as he started all of these symptoms right after getting his shots.    He is fine now, and doesn't scratch hardly at all anymore, no more bumps and illnesses. Thank goodness!!!
Some of these drugs do help but in the end, there is usually a price to pay.  My sister in law at the time worked at a nursing home and said that is exactly what happened there to the people,,they would get on antibiotics or steroids,,be fine while on them, and then after they were off they were worse then before.  
Please keep us updated on Hap!

Awww, poor girl! I really hope that she feels better soon!

Okay I sat here forever crying and trying to type a good response to you but I cant seem to muster it up.  I recently lost mmy Kayla to pancreatitis within a few days of her being diagnosed with it, she was 3.  I did lots of research and never understood the severity of it, the websites that talk about it dont warn how deadly it is...  Heres her story

[linkhttp://forum.dog.com/asp/tm.asp?m=12015&mpage=1&key=kayla%2Cstopped%2Ceating⻯]http://forum.dog.com/asp/tm.asp?m=12015&mpage=1&key=kayla%2Cstopped%2Ceating⻯[/link]

Keep us updated

I'm sorry for the things that you had gone through with your fur child, it was sad to read your story, but I'm glad that she past away next to you and your partner, and that she past away with no pain or isn't suffering. She such a cutie.

To original poster, I hope your furchild is ok, and please keep update.

Pancreatitis can come from several 'directions' but prednisone can hurt the kidneys, pancreas, liver and other organs.  However, if you treat it in time, and if you are very careful with diet and other things you can see the dog thru it.
 
My Prissy (this was MANY MANY years ago -- like 30!) started with pancreatitis when she was 3.  It didn't even take a high fat "diet" -- but simply snagging someone's leftover box of KFC chicken on the street while my friend and I were talking.  It must have had leftover skin and I thot she'd eaten splintery chicken bones.  The vet treated it wrong because of that (not his fault -- we went by what we had seen) and oh my, she nearly died.  But she DID pull thru.  In fact she had two other very serious recurrences over the next few years.
 
BUT Prissy lived to be nearly 21.  Yep.  She was the dog I learned to home cook for!  She was on a "bland diet" of rice and burger just about forever.  Later I added veggies to it (much later actually).  I used an enzyme similar to ProZyme to help break down her food before it got to her stomach.