Runny nose

Runny nose (rhinorrhea) in the context of psychoactive substance use refers to excessive production and discharge of nasal mucus. The nasal mucosa is a highly vascularized tissue that produces mucus continuously as part of its role in humidifying and filtering inhaled air. Psychoactive substances can dramatically increase this baseline mucus production through several mechanisms.

During opioid withdrawal, rhinorrhea is one of the hallmark early symptoms, typically appearing within 8-24 hours after the last dose of a short-acting opioid. The mechanism involves sympathetic nervous system rebound. Chronic opioid use suppresses autonomic activity through mu-opioid receptor activation. When opioids are discontinued, the sudden removal of this suppression results in a surge of noradrenergic and cholinergic activity that stimulates mucus-secreting glands throughout the body, including the nasal mucosa. The rhinorrhea is typically accompanied by other withdrawal symptoms: lacrimation (watery eyes), yawning, sweating, piloerection (goosebumps), and muscle aches.

Direct nasal mucosal irritation is the primary cause of rhinorrhea associated with insufflated substances. Snorting any powdered substance irritates the delicate nasal epithelium, triggering an inflammatory response that increases mucus production as a protective mechanism. Substances that are caustic, have extreme pH values, or contain adulterants are particularly irritating. Cocaine is especially damaging to nasal tissue because it also causes intense local vasoconstriction, which reduces blood supply to the mucosa and can lead to tissue necrosis with chronic use.

Some psychedelics produce mild rhinorrhea during the come-up phase as part of a general parasympathetic activation that includes salivation, lacrimation, and increased GI motility. Dissociatives, particularly ketamine, can produce nasal discharge through both direct irritation (when insufflated) and autonomic effects.

Management is straightforward: tissues, hydration, and time. For opioid withdrawal rhinorrhea, clonidine or loperamide may provide symptomatic relief as part of a broader withdrawal management protocol. For insufflation-related rhinorrhea, saline nasal rinses after substance use help clear irritants and soothe the mucosa. Persistent or bloody nasal discharge warrants medical evaluation, particularly in chronic cocaine users.