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It sounds likely your dog suffers from some acid reflux. I would try giving some Pepcid (famotidine) at a dose of 0.25mg per pound of body weight just before the time of day he usually does this, as long as he is healthy otherwise (no liver/kidney disease or on heart medications). You can repeat the pepcid in 12 hours as well if needed.
You'll also want to start feeding more times per day in order to combat this built up stomach acid, say 2x's a day instead of 1. Feed late at night as well to better keep his stomach fuller during the overnight. The late meal along with the pepcid should make a big difference.
If he continues to vomit occasionally only when hungry, you may want to consider changing his diet to one with a more fulfilling, higher quality protein (which any pet supply store can help you compare with quality and price). This will help him not digest too quickly so as to not have such an empty stomach. If all this fails or if your dog appears ill at any time, of course a vet visit and some basic bloodwork is always a good idea to rule out more serious problems.
Here's some more info about Pepcid. If any concerns, it is always best to check with your vet before giving:
No, you don't want to increase any medication dosing. Instead, as stated in first answer, if vomiting continues and above advice with fasting and only feeding tiny amounts of food or water at a time was followed, then regardless how he looks, something more than stomach upset is going on and a vet is needed for a diagnosis to determine how best to treat.
Good luck to you both.