Eye drops are medications formulated for topical application to the eye, delivering a localized dose of medication to the ocular surface. Ingestion of these products, particularly those intended to relieve eye redness, can be unexpectedly dangerous and requires immediate medical intervention. The concentration of active ingredients in these small bottles is potent when absorbed systemically through the gastrointestinal tract. This article explains which types of drops pose a threat, the physiological effects of ingestion, and the urgent steps necessary following exposure.
Identifying High-Risk Eyedrops
The risk associated with drinking eyedrops is not uniform across all products. Many common drops, such as artificial tears, lubricating formulas, or sterile saline solutions, pose little toxic threat if swallowed, generally causing only mild stomach upset. These drops are primarily composed of non-toxic electrolytes and thickeners.
The greatest danger is found almost exclusively in over-the-counter formulas marketed as redness-relievers or decongestants. These products contain potent vasoconstrictor medications to shrink the small blood vessels on the eye’s surface. Because these medications are often sold without child-resistant packaging, they represent a significant accidental poisoning hazard, especially for young children.
How Vasoconstrictors Affect the Body
The toxic ingredients in high-risk eyedrops are typically imidazoline derivatives like Tetrahydrozoline, Naphazoline, or Oxymetazoline. These compounds are alpha-adrenergic agonists, meaning they activate alpha-adrenergic receptors in the body. When applied to the eye, this action causes localized vasoconstriction, which reduces redness.
When ingested, these compounds are rapidly absorbed into the bloodstream from the stomach and intestines, leading to systemic effects. Once in the circulation, the drugs act on the central nervous system (CNS), specifically stimulating alpha-2 receptors in the brain. This central action overrides the peripheral vasoconstriction, leading to a sudden and dangerous drop in heart rate and blood pressure.
The concentration of medication means that even a small amount can be toxic; as little as 1 to 2 milliliters can cause pronounced reactions in a small child. The rapid systemic absorption of these concentrated ingredients creates a toxicological emergency. The initial peripheral vasoconstriction can sometimes cause a transient rise in blood pressure, but this is quickly followed by profound, life-threatening CNS depression and cardiovascular collapse.
Recognizing Signs of Systemic Poisoning
Symptoms of systemic poisoning from these vasoconstrictor eyedrops can manifest quickly, often within 30 minutes to two hours of ingestion. The most common and serious effects involve the cardiovascular and central nervous systems. A significant drop in heart rate, known as bradycardia, is one of the clearest indications of poisoning.
The accompanying drop in blood pressure, or hypotension, can lead to inadequate blood flow to the body’s organs. Victims frequently exhibit pronounced central nervous system depression, appearing lethargic, drowsy, or extremely sedated, which can rapidly progress to a coma. Respiratory depression, characterized by slow or shallow breathing, is another serious sign.
Other observable symptoms include miosis, or pinpoint pupils. Victims may also experience nausea, vomiting, or a dangerously low body temperature, called hypothermia. The combination of slowed heart rate, low blood pressure, and profound sleepiness is a hallmark of this specific type of poisoning and signals an urgent need for medical care.
Immediate Steps Following Ingestion
If a person has ingested any amount of a redness-relieving eyedrop product, the first step is to seek expert medical advice immediately. Do not wait for symptoms to appear, as the onset can be rapid and severe. The primary resource is the national Poison Help Line (1-800-222-1222), which connects callers to the nearest Poison Control Center for guidance.
If the person is unconscious, having difficulty breathing, or experiencing a seizure, call emergency services (911) immediately. While awaiting help, try to determine the exact name of the product, the estimated amount swallowed, and the time of ingestion, as this information is vital for medical professionals. Do not attempt to induce vomiting or give the person anything to drink unless specifically instructed by Poison Control Center staff.
Medical treatment typically involves hospitalization and supportive care, focusing on monitoring and stabilizing the heart rate, blood pressure, and breathing. Patients often require close observation in an intensive care setting until the effects of the drug have completely worn off, which may take up to 24 to 72 hours.