Hi Dear, Welcome to Health Care Magic Team. Understanding your concern. As describe by you that doctor has already ruled out diabetes .so we will lookout for some other reasons a constant sweet taste in your mouth may indicate that you have taste impairment, meaning there’s a problem with your ability to taste. There are many reasons for taste impairment, including a nasal infection, cold, or flu. It could also be related to an ear infection, vitamin B12 or zinc deficiency, swollen gums, certain medications you are taking, a side effect of smoking pipes, exposure to some chemicals (such as insecticides), or dental problems. If the taste disorder is related to your dental hygiene or care, your dentist can diagnose the problem. Otherwise you might want to see your doctor. An ENT specialist should be consulted about taste impairment problems, such as a constant sweet taste in your mouth. Neurologic problems such as a stroke, seizure disorder or epilepsy can also cause this problem. The patient may not even be aware that they are having a seizure, epilepsy or a stroke because this may be the only symptom. Furthermore, virus that attack the olfactory nerve or taste nerve can lead to this sweet taste. On the other hand, infection in the sinuses, nose and/or throat, especially with the bacteria pseudomonas, can give you a sweet taste or smell. The problem of dry mouth is most probably due to side effects of gabapentin Hope your concern has been resolved. Best Wishes, Dr. Harry Maheshwari