Belching is frequently seen in functional dyspepsia and gastroesophageal reflux disease. Only a minority of patients suffer from so-called ‘excessive supragastric belching’ (SGB) characterized by numerous belches/min. In SGB, air is either sucked or pushed into the upper esophagus by decreased intrathoracic pressure or contraction of pharyngeal muscles during closure of the glottis. The subsequent air expulsion results in a burping sound. Important differential diagnoses are persistent hiccups (singultus), aerophagia, dyskinesia as well as tics.
We report the case of a 55-year-old man who presented with a 2-year history of therapy-refractory SGB with up to 25 belches/min. He denied premonitory sensations and was unable to voluntarily suppress belching. Numerous medications, including gabapentin 2400 mg/day, tetrabenazine 150 mg/day, trihexyphenidyl hydrochloride 15 mg/day, tiapride hydrochloride 600 mg/day, valproate 1800 mg/day, carbamazepine 1200 mg/day and baclofen 30 mg/day, had not resulted in meaningful improvement. He had been on 40 mg pantoprazole for reflux esophagitis and recurrent gastric ulcers for at least 10 years without a marked effect on his belching.
Esophageal impedance manometry demonstrated excessive SGB, but yielded no evidence for hiccups or respiratory dyskinesia. Cranial magnetic resonance imaging and thoracoabdominal computed tomography were without note. Gastroscopy demonstrated moderate erosive esophagitis.
There is little evidence to guide the management of SGB. Biofeedback and behavioral therapy may be beneficial. However, these procedures are complex and few therapists have experience in this specific area. Here, combined treatment of 10 mg baclofen t.i.d. and 100 mg pregabalin t.i.d. resulted in sustained reduction of the rate of belching to less than 10% of the pretreatment value. The patient reported initial mild sedation, which resolved during the second week of treatment. We speculate that the combination of baclofen and pregabalin exerts synergistic effects by reducing both increased mechanosensitivity and chemosensitivity of the esophagogastric junction associated with SGB.
Blondeau and co-workers showed a correlation between increased lower esophageal sphincter pressure under baclofen therapy and a reduction in belching events. Experimentally, baclofen inhibits mechanosensitivity of vagal afferents peripherally. However, baclofen does not affect chemosensitivity. Recently, a small placebo-controlled study showed that pregabalin attenuates the development of hypersensitivity in the proximal esophagus after distal esophageal acidification.
In conclusion, clinicians should be aware of the disease entity of SGB. Further studies will have to establish an evidence-based approach to the management of these patients.