can only say from my experience of vertigo, that no medication works, however you can do exercises that the doctor can give you to help with it. If it persists ask to be referred to Ear Nose and Throat specialist as they are the ones who can really help. One thing i can advise is when getting up from bed, or out of a chair is to do it very slowly, take your time, because rushing either makes it much worse.
Who diagnosed you with labrinthitis? if it was a GP he/she could be wrong, get ENT people to take a look.