Brief Answer:
Not documented.

Detailed Answer:
Hello,

Welcome and thanks for your query.
Warfarin can produce gastrointestinal symptoms of stomach or upper abdominal pain, nausea and vomiting. Acid reflux is not a documented side effect and it has no effect on the lower esophageal sphincter producing relaxation of the same and an acid reflux.
Metoprolol again has side effects of dyspepsia, abdominal/ stomach pain, nausea and vomiting. Again there is no documented acid reflux by way of endoscopic or manometric examination.
However undocumented side effects do occur and if you have felt acid reflux which is not related to any other cause like food , medicine s or stress and if the symptom goes away by stopping the medication, then it is a valid conclusion that the acid reflux may be related to the medicines.
You can take a PPI , Pantoprazole which does not have any interaction with warfarin or metoprolol for symptomatic relief. The commonly used PPI omeprazole has an adverse interaction with Warfarin and would be better avoided.
Do get back to me if you have more queries.

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Brief Answer:
An upper GI endoscopy would be advisable

Detailed Answer:
Welcome back XXXXXXX
I think it would be good for you to have an upper GI endoscopy if your gastroenterologist suggests it. At that time he/she will be able to visualise the esophagus, the stomach and the duodenum and assess the degree of inflammation. Also there would be an opportunity to test for a disease producing bacteria called H.Pylori which produces inflammation and ulceration. Further would be able to see if there is any laxity of the lower esophageal sphincter producing reflux.
If there is appropriate treatment can be taken to give you good relief.
I would be interested in knowing his/her opinion and the findings if you have an endoscopic examination.
Hope you get well soon.
Regards,

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