I think it's safe to assume that everyone here has had enough sports related injuries to have an opinion:
Ive had tendinitis in my elbow for about a month. Took 800mg ibuprofen for a week, then saw my doctor who upped it 1800mg a day until I'm healed, or for up to a month - whichever comes first.
He's the doctor, but does that sound excessive to you? I've been on the 1800mg dose for a week so far and my arm is slowly feeling better, but I'm worried about F'ing up my liver or kidneys if I stay on this dose for another week or two. 
I've had tennis elbow for over 3 months..gotten better,and can start training. Sounds like a lot , but like you said, he's the doc. Make sure your not taking anything else that can worsen th IB, ie. no booze!
a lot of people get weird about ibuprofen
for sports injuries, 800mg/3x day is normal
my last bjj injury i went to a new doctor, i told her i had been on that dosage self-medicating for two weeks and if i should stop
she laughed and said she had patients on that for 6 months+
she said if it starts to irritate my stomach take some prilosec/omeprazole
otherwise party on
About the tennis elbow, did you not lift completely or just wear a brace? I've been dealing with tennis elbow for 3 months or so now. It's not getting worse but not getting better either.
With so many methods of dealing with elbow inflammation, its silly to take a drug which has the mildest side effect of ulceration and bleeding in the stomach.
Take it when you need it, avoid it when you don't.
I got put on 800mg 3x a day for a month when I fucked up my knee. Think it's fairly xommon
sounds like a good way to destroy your stomach.
plus, it wont do anything to cure your tennis elbow in the long run. you need professional soft tissue work, rehab/strengthening exercises, stretching, ice and electro stim. low level laser can also help if your PT has one. basically you need to find a good PT who works with athletes(tennis players and baseball players in particular)...its the only way to really get rid of the problem.
Is it 1800mg a dose or over the course of the day?
Is it OTC or script?
A typical heavy dosage for a large musclar person (190+) is in the range of 400-600mg 4x a day so you're in the mid range of that. Script version means it has less fillers in it which is nice but can be harder on the system.
4 grams of Cissus and 12 grams of fish oil per day = miracle cure for my joints.
Active Release Technique (ART) helped me with tennis elbow after the first day!!! I know some/a lot of people don't believe in chiro but all I can say is this was the best and fastest solution