Dry mouth (also known as xerostomia) is defined as having a dry-feeling mouth, often accompanied by a difficulty swallowing. It is usually a direct result of dehydration but can be felt to occur regardless of the actual dryness of a person's mouth.
Chronic xerostomia or "dry mouth syndrome" is the regular and/or consistent experience of having a dry mouth that can result due to natural causes or as a product of the prolonged usage of mouth-drying substances. To treat this condition, substances such as cevimeline which stimulate the release of saliva are typically used. However, a problem noted with repeated use of such treatments is the overall worsening of the dry mouth symptoms over time. If the body adjusts to having chemical assistance in increasing saliva production cessation of treatment with the chemical can lead to physiological dependence wherein there is a rebound effect upon abrupt stopping of treatment.
In general, if the cause of dry mouth is due to a psychoactive substance, medication, or combination, medical treatment is not recommended. Dry mouth as an effect of substances is considered to be benign unless the effect is chronic and continues to bother or cause tooth/gum issues in the person experiencing it. As a basic harm reduction practice one should be mindful to stay consistently well hydrated, avoid breathing through the mouth, and limit substance usage if the effect becomes uncomfortable, unmanageable, or persists even when not under the influence of a psychoactive substance.
Dry mouth is often accompanied by other coinciding effects such as frequent urination (due to drinking excessive amounts of water) and dehydration. It is most commonly induced under the influence of moderate dosages of a wide variety of compounds, such as stimulants, psychedelics, opioids, antispychotics, deliriants, SSRI's, and cannabinoids. It is also a common side effect of many substances, especially the combination of more than one substance which can produce or amplify already present experience of a dry mouth, which can interact significantly.
Compounds within our psychoactive substance index which may cause this effect include: