Bismuth Subsalicylate Overdose in Children: Tinnitus, Acidosis, and ER Warning Signs

Bismuth subsalicylate is the active ingredient in products such as Pepto-Bismol and some medicines for diarrhea, nausea, and indigestion. It contains a salicylate, a drug-related chemical family that also includes aspirin. Although a small, correctly measured dose is usually tolerated by appropriate age groups, too much can cause serious poisoning in children.

Children can be affected by a smaller amount than adults, especially if they are dehydrated, have kidney disease, or take other medicines containing salicylates. Understanding bismuth toxicity symptoms in children can help caregivers recognize when home observation is not enough.

Why an overdose can be dangerous

Bismuth subsalicylate poisoning can cause problems from both parts of the medicine:

• Salicylate toxicity: This may affect the brain, lungs, acid-base balance, kidneys, and metabolism.
• Bismuth toxicity: This is more commonly associated with repeated or prolonged high doses and may affect the nervous system.

A single extra dose does not always result in severe poisoning, but the risk depends on the child’s age, weight, amount taken, product strength, timing, and whether other medicines were also used. Some liquid and chewable products have different concentrations, so estimating the amount by appearance alone can be unreliable.

Children and teenagers with a current or recent viral infection should not be given salicylate-containing products unless a clinician specifically recommends them. Salicylates have been associated with Reye syndrome, a rare but potentially life-threatening condition affecting the liver and brain. Always check the product label and ask a pharmacist or doctor if you are unsure whether a medicine is appropriate.

Early bismuth toxicity symptoms in children

Symptoms can begin with stomach or general illness symptoms and may initially look like a worsening stomach bug. Possible signs include:

• Nausea or repeated vomiting
• Stomach pain
• Diarrhea
• Ringing, buzzing, or roaring in the ears
• Hearing changes
• Dizziness or unusual sensitivity to sound
• Sweating
• Fast breathing
• Increased thirst or dehydration
• Weakness, drowsiness, or unusual tiredness
• Headache
• Irritability, restlessness, or confusion

Tinnitus is an important warning sign. Ringing in the ears after taking bismuth subsalicylate may indicate salicylate exposure, particularly if it occurs with vomiting, rapid breathing, dizziness, or changes in behavior. A young child may not say “my ears are ringing.” They may cover their ears, seem distressed by normal sounds, become unusually quiet, or complain that their hearing feels strange.

Do not wait for tinnitus to appear before seeking advice. Serious salicylate poisoning can develop without obvious early symptoms, and symptoms may change as the medicine is absorbed.

Acidosis and other severe symptoms

Salicylate poisoning can disturb the body’s acid-base balance. Metabolic acidosis means that the blood becomes too acidic. This cannot be diagnosed reliably at home; it requires medical assessment and blood testing.

Possible signs of acidosis or severe poisoning include:

• Deep, rapid, or unusually labored breathing
• Breathing that seems too fast for the child’s activity or fever
• Confusion, agitation, unusual behavior, or difficulty waking
• Severe weakness or loss of coordination
• Persistent vomiting
• Fainting
• Seizures
• Very little urine
• Cold, pale, or clammy skin
• Loss of consciousness

A child may initially appear restless or overactive and later become sleepy or difficult to wake. This change is especially concerning. Severe salicylate poisoning can affect temperature regulation, blood sugar, fluid balance, and brain function, even when the amount swallowed did not seem large.

When to go to the emergency room

Call emergency services immediately or go to the nearest emergency department if a child who may have taken bismuth subsalicylate has:

• Ringing in the ears or new hearing symptoms
• Fast, deep, or difficult breathing
• Confusion, extreme sleepiness, collapse, or a seizure
• Repeated vomiting or inability to keep fluids down
• Severe dizziness, weakness, or trouble walking
• Signs of dehydration, such as very little urination, a dry mouth, no tears, or marked lethargy
• An unknown amount of medicine missing
• Taken several medicines, especially aspirin, cold remedies, pain relievers, or other salicylate-containing products
• A serious medical condition, such as kidney disease, or is taking blood thinners
• Any symptoms that are rapidly worsening

If the child is unconscious, having trouble breathing, or having a seizure, call emergency services now. Do not give food, drink, or additional medicine unless emergency professionals tell you to do so.

For a child who is awake and appears well but may have taken too much, contact your regional poison control center or an equivalent poison advice service promptly. Poison specialists can calculate risk using the child’s weight, product name, strength, amount, and time of exposure. Do not wait for symptoms to develop, and do not assume that a child is safe simply because the first hour has passed.

What caregivers should do after a possible overdose

Keep the medicine container, packaging, or a photograph of the label available. Note:

• The product name and strength
• Whether it was a liquid, tablet, or chewable product
• The estimated amount taken
• The time of exposure
• The child’s age and weight
• Any symptoms already present
• Other medicines taken that day

Do not make the child vomit. Do not give activated charcoal, baking soda, antacids, aspirin, or another pain reliever unless instructed by a poison specialist or emergency clinician. These actions can cause additional problems or make treatment more difficult.

Medical teams may check blood salicylate levels, electrolytes, kidney function, glucose, and acid-base status. They may also monitor breathing, hydration, mental status, and urine output. Treatment depends on the severity and timing of the exposure. Severe cases may require intensive monitoring and specialized hospital treatment.

What is normal after a standard dose?

Bismuth products can temporarily turn the tongue or stool dark gray or black. This can be an expected effect of bismuth and is not, by itself, proof of an overdose. However, black stool with weakness, fainting, vomiting blood, severe abdominal pain, or ongoing illness needs medical attention because bleeding can also cause black stool.

Mild stomach upset can occur, but tinnitus, rapid breathing, confusion, persistent vomiting, or unusual drowsiness should not be dismissed as ordinary side effects.

Never use an adult product for a child unless a healthcare professional has confirmed the product and dose. Store medicines locked away and avoid describing them as candy. If diarrhea, vomiting, or fever continues, ask a doctor or pharmacist about safer age-appropriate treatment and hydration.

If you are unsure how serious a child’s symptoms may be, you might consider a free, online symptom check, using the doctor approved Ubie Symptom Checker. It can help organize symptoms and suggest appropriate next steps, but it cannot assess an overdose or replace urgent medical care.

Most important, speak to a doctor about any possible overdose, tinnitus, breathing changes, confusion, dehydration, or other symptom that could be life-threatening or serious. When the amount taken is unknown or the child is showing warning signs, prompt professional advice is the safest choice.