ConditionInjuries & poisoning
Drug Poisoning Due to Medication
Drug poisoning due to medication means harm from taking too much of a prescription or over-the-counter medicine, or from a normal dose that builds up to toxic levels. It happens through dosing mistakes, children getting into medicines, drug interactions, kidney or liver problems, or intentional overdose. Signs range from drowsiness and vomiting to confusion, slow breathing and seizures. If you suspect it, call Poison Control at 1-800-222-1222 (US), or 911 if the person is very unwell.
Also called: Medication overdose, drug toxicity, prescription drug poisoning, medication poisoning, adverse drug toxicity
At a glance
- What it is
- Harm from a toxic amount of a medicine, taken all at once or built up over time.
- Common culprits
- Acetaminophen (paracetamol), opioids, sedatives, antidepressants, heart and blood pressure medicines, diabetes medicines, blood thinners.
- Typical signs
- Drowsiness, vomiting, confusion, slow or fast heartbeat, slow breathing, seizures.
- First step
- Call Poison Control at 1-800-222-1222 (US) or 911 if the person is collapsed, not breathing normally or seizing.
- Treatment
- Supportive care, activated charcoal in some cases, and specific antidotes such as naloxone or acetylcysteine.
When to get help
Call 911 or go to the ER
- Unconscious, cannot be woken, or breathing slowly, noisily or not at all: call 911 and give naloxone if opioids may be involved
- A seizure, chest pain, a very slow or very fast heartbeat, or fainting
- Any intentional overdose, even if the person feels fine. Acetaminophen can cause liver failure after a symptom-free day
- Thoughts of self-harm or suicide: call or text 988 (US) or 911
See a doctor within a day or two
- A child who may have swallowed any adult medicine, especially opioids, heart pills, diabetes tablets, iron or button-sized patches: call Poison Control now, even without symptoms
- A double dose or wrong medicine taken by mistake: call Poison Control for advice
- New confusion, falls, vomiting or blurred vision after a dose change or a new medicine is added
Book a routine appointment
- Ongoing side effects such as drowsiness or dizziness that you think may be from your medicines
- Taking 5 or more medicines regularly: ask for a medication review
What to do right now
- Check responsiveness and breathing. If the person is unresponsive or not breathing normally, call 911 and start CPR if you are trained.
- If opioids could be involved, give naloxone (Narcan) nasal spray if you have it. It is available without a prescription in the US.
- Call Poison Control at 1-800-222-1222 (US) if the person is awake and breathing. Experts answer 24 hours a day, for free. Many cases can be managed safely at home with their advice.
- Keep the packaging. Note the medicine name, strength, how much was taken and when. Bring containers to the ER.
- Do not make the person vomit, and do not give salt water, milk or "remedies". Do not give anything by mouth to a drowsy person.
- Place a drowsy person on their side (recovery position) so they do not choke if they vomit.
How medication poisoning happens
- Accidental overdose: taking two products with the same ingredient (for example a cold remedy and a pain reliever that both contain acetaminophen), taking doses too close together, or mixing up pill bottles.
- Children: young children swallow pills, gummies, liquid medicines and patches. A single adult tablet of some medicines can be dangerous to a toddler.
- Drug interactions: one drug can slow the breakdown of another, pushing it to toxic levels. Alcohol adds to the effect of sedatives and opioids.
- Reduced clearance: worsening kidney or liver function, dehydration or older age lets normal doses build up. This is a common cause of digoxin toxicity and lithium toxicity.
- Polypharmacy: taking many medicines raises the chance of errors and interactions. See polypharmacy.
- Intentional overdose: in the setting of depression, crisis or substance use.
Signs of toxicity by type of medicine
| Medicine group | Typical toxic effects |
|---|---|
| Acetaminophen (paracetamol) | Often none at first. Nausea, then right upper belly pain and liver damage after 1 to 3 days |
| Opioids | Pinpoint pupils, extreme sleepiness, slow or stopped breathing |
| Benzodiazepines and sleeping pills | Drowsiness, slurred speech, unsteadiness, slow breathing when combined with alcohol or opioids |
| Tricyclic and some other antidepressants | Fast heart rate, dangerous heart rhythms, seizures, confusion |
| NSAIDs (ibuprofen, naproxen) | Stomach pain, vomiting, kidney injury in large doses |
| Aspirin and salicylates | Ringing in the ears, fast breathing, vomiting, confusion |
| Diabetes medicines (insulin, sulfonylureas) | Low blood sugar: sweating, shaking, confusion, seizures |
| Blood thinners | Bleeding gums, bruising, blood in urine or stool |
| Heart and blood pressure medicines | Very slow pulse, low blood pressure, fainting |
| Lithium | Tremor, diarrhea, vomiting, confusion, unsteady walking |
| Iron tablets | Vomiting, bloody diarrhea, then shock, especially in children |
How doctors treat it
In the ER, treatment starts with the airway, breathing and circulation. Doctors then:
- Check blood levels of acetaminophen and aspirin in every intentional overdose, and of specific drugs such as digoxin, lithium or anticonvulsants when relevant.
- Run an ECG to look for heart rhythm effects.
- Give activated charcoal in some cases, usually only within about 1 hour of swallowing and only if the person is alert enough to swallow safely.
- Give antidotes where they exist: naloxone for opioids, acetylcysteine for acetaminophen, glucose for low blood sugar, digoxin-specific antibodies, and others.
- Provide supportive care: fluids, oxygen, heart monitoring and, rarely, dialysis or a breathing machine.
After an intentional overdose, a mental health assessment is part of standard care.
Recovery and outlook
Most people who get prompt care recover fully. The outcome depends on the drug, the amount, and how quickly treatment starts. Acetaminophen poisoning treated within 8 hours almost never causes serious liver damage, while late treatment can lead to liver failure.
Preventing medication poisoning
- Store all medicines up and away, out of sight, in child-resistant containers, and put them away after every use.
- Keep an up-to-date list of everything you take, including supplements, and share it with every doctor and pharmacist.
- Read active ingredients on every label so you do not double up.
- Use the measuring device that comes with liquid medicines, not a kitchen spoon.
- Use a pill organizer if you take several medicines.
- Dispose of unused medicines through take-back programs.
- Save the Poison Control number in your phone: 1-800-222-1222.
Frequently asked questions
What are the first signs of drug toxicity?
Early signs are often vague: nausea, vomiting, drowsiness, dizziness, confusion, blurred vision or a change in heart rate. Some medicines, such as acetaminophen, cause few symptoms at first even when a dangerous amount was taken, so call Poison Control whenever an overdose is possible.
What should I do if I accidentally took a double dose?
Call Poison Control at 1-800-222-1222 (US) or ask your pharmacist. For many medicines a single extra dose is not dangerous, but for others, such as heart, diabetes or opioid medicines, it can be. Do not take your next dose until you have advice.
Can a normal dose of medicine cause poisoning?
Yes. If your kidneys or liver slow down, if you become dehydrated, or if a new drug interacts with an old one, a usual dose can build up to toxic levels. This is common in older adults and with digoxin, lithium and some anti-seizure medicines.
Should I make someone vomit after an overdose?
No. Inducing vomiting is no longer recommended. It does not remove much of the drug and can cause choking or injury. Call Poison Control or 911 instead and follow their instructions.
What is the difference between an overdose and drug poisoning?
The terms overlap. Overdose usually means taking more than the intended amount at one time. Drug poisoning or toxicity is broader and also includes gradual buildup and interactions. The general overdose page covers recreational drugs and alcohol too.
Sources
This guide was written from current patient and clinical guidance, including:
- America's Poison Centers: Medicine safety
- CDC: Medication safety program, adverse drug events
- MedlinePlus: Drug overdose; Poisoning
- FDA: Where and how to dispose of unused medicines
- NHS: Poisoning