What is Caffeine Toxicity?
Caffeine is a substance that helps to boost mental alertness and has been used all over the world for hundreds of years. Around 85% of Americans drink caffeine daily, and the typical cup of coffee has between 40 to 150 mg of caffeine. Caffeine is also found in a lot of things you can buy without a prescription, like energy drinks, diet aids, workout supplements, decongestants (medication to relieve nasal congestion), bronchodilators (medicine to open up airways), and brain boosters. This increases the risk of consuming too much caffeine unintentionally, or severe poisoning in case of a deliberate overdose.
It’s been reported that deadly amounts of caffeine can occur at blood concentrations of 80 to 100 micrograms/ml. This could happen from consuming roughly 10 grams of caffeine or more.
What Causes Caffeine Toxicity?
It’s very rare, but deadly caffeine overdoses can happen in adults. When they do, it’s usually because someone intentionally took too many medications that contain caffeine.
On the other hand, children usually get caffeine poisoning by accidentally eating or drinking something with caffeine in it. This can happen after having energy drinks, but it’s not common with coffee or tea. That’s because you’d have to drink a massive amount of fluid to get to dangerous levels of caffeine from these sources.
You can also find caffeine in many over-the-counter drugs that you don’t need a prescription for. People often buy these for the energy boost caffeine gives. Some examples include health food products, diet aids, decongestants, drugs for treating asthma, or pills to help you stay awake. So, overusing these kinds of products can lead to taking in too much caffeine.
Risk Factors and Frequency for Caffeine Toxicity
In 2016, there were 3,702 reported cases of caffeine-related health problems in the US, as recorded by Poison Control Centers. These cases were split evenly between children and adults. Out of these, 846 people needed medical attention, and 16 cases had severe consequences. It’s important to note that there have been instances of life-threatening conditions related to caffeine recorded in case studies.
Signs and Symptoms of Caffeine Toxicity
Physical signs of too much caffeine (caffeine toxicity) generally start with fever, either a fast or a slow heart rate, and high blood pressure that later becomes low pressure. Other symptoms may include dilated pupils, muscle stiffness, and exaggerated reflex responses. Neurological symptoms can also occur, such as changes in mental function, agitation, delusions, hallucinations, seizures, or specific findings related to blood supply reduction from tightened blood vessels. It’s also common for patients to feel nauseous and frequently vomit.
- Fever
- Fast or slow heart rate
- High blood pressure, which later drops
- Dilated pupils
- Stiff muscles
- Exaggerated reflex responses
- Changes in mental function
- Agitation
- Delusions
- Hallucinations
- Seizures
- Specific findings related to reduced blood supply due to tightened blood vessels
- Nausea and frequent vomiting
Testing for Caffeine Toxicity
In cases of drug overdose, blood tests can be very helpful, particularly if the person is showing signs of serious illness, like instability, seizures, or changes in consciousness. One thing doctors might test for is caffeine levels in the blood, which can help predict the person’s health outcome and guide their treatment. Although not all hospitals can perform this, getting a person’s serum caffeine level is typically done using a method called immunoassay. Levels above 80 to 100 mg/L are typically associated with death, although it’s important to note that serious side effects can occur at lower levels too.
Another type of blood test, called a venous blood gas, can be used to see if there’s an excess of acid in the person’s blood, which can sometimes be the case in a drug overdose. This test can also check if lactic acid is high, another common finding in cases of drug overdoses. It’s also possible to find low levels of potassium, calcium, and sodium but high levels of glucose in the blood. For this reason, testing for serum myoglobin and creatine kinase is usually done to monitor for a condition called rhabdomyolysis.
Apart from these, an electrocardiogram (ECG), which is a test that measures the electrical activity of the heartbeat, can also be helpful in detecting abnormalities that might stem from caffeine toxicity. This test can identify abnormal heart rhythms like rapid heartbeat, changes in the ST segment (part of the ECG wave), or T-wave inversions (abnormalities in another part of the ECG wave). Regular monitoring of the individual’s heart rate can help in early detection of abnormal heart rhythms like ventricular ectopy or fibrillation.
Treatment Options for Caffeine Toxicity
Overdosing on caffeine is not a common event, and there isn’t a lot of information available on how to treat it since most of the data comes from individual cases rather than wide-scale studies. If someone takes in a small amount of caffeine, the main treatment typically involves providing support and comfort to the person. Drinking fluids is important, whether it’s done on their own in mild cases or given through an IV in more severe conditions.
Certain medications might help if the heart is beating too fast because of the caffeine. Esmolol, for example, is used to slow down the heart rate. Other drugs like procainamide, lidocaine, or bicarbonate could address irregular heart rhythms. When the blood pressure dips too low, medications like vasopressin or phenylephrine can help bump it back up to a safer level.
Activated charcoal, a substance that has a knack for latching onto other substances, might help if the caffeine was consumed quite recently. It can bind to the caffeine in the stomach and intestines, and taking repeated doses can help lower the amount of caffeine in the bloodstream.
In extremely serious instances where a person’s life is in danger, hemodialysis can be used. This is a process that filters waste products from the blood, and since caffeine is a small molecule that isn’t tightly bound to proteins in the body, it can effectively be removed this way.
In severely severe cases where someone might go into cardiac arrest from caffeine toxicity, lipid therapy can be considered. This involves infusions of fats that have been shown to help remove free-floating caffeine in the blood.
What else can Caffeine Toxicity be?
There are several conditions that can cause severe health issues, which include but are not limited to:
- Atrial fibrillation or flutter (heart rhythm disorders)
- Carbon monoxide toxicity (poisoning from too much carbon monoxide)
- Cyanide toxicity (poisoning from too much cyanide)
- Delirium tremens (severe alcohol withdrawal symptoms)
- Diabetic ketoacidosis (high blood sugar complication)
- Disulfiram toxicity (reaction to alcohol-abuse drug)
- Intracranial hemorrhage (bleeding within the skull)
- Iron toxicity (poisoning from too much iron)
- Monoamine oxidase inhibitor toxicity (reaction to certain type of antidepressants)
- Multifocal atrial tachycardia (abnormal heart rhythm)
- Polysubstance overdose (overdose from multiple drugs)
- Septic shock (serious infection that causes low blood pressure)
- Status epilepticus (prolonged seizure)
- Theophylline toxicity (reaction to medication for respiratory diseases)
- Thyrotoxicosis (symptoms due to high levels of thyroid hormone)
- Ventricular fibrillation (life-threatening heart rhythm problem)
- Ventricular tachycardia (rapid heart rate)
What to expect with Caffeine Toxicity
There are few deaths related to caffeine overdose, but the patient’s condition largely depends on how quickly they receive treatment. If someone has a severe caffeine overdose, their chance of recovery is directly linked to how quickly the caffeine can be removed from their body. This is often carried out using treatments like hemodialysis, which is a procedure that filters waste and water from your blood, or intralipid emulsion therapy, which is a treatment that aims to reverse the effects of certain drug overdoses.
Possible Complications When Diagnosed with Caffeine Toxicity
Overdosing on caffeine can lead to several health problems. These include having seizures, changes in your brain function, irregular fast heartbeat, changes in your ECG (a test that checks your heart’s activity), low levels of potassium in your blood, high levels of sugar (glucose) in your blood, and high levels of acid in your body due to lactic acid (a substance your body produces). If the condition worsens, it can lead to sudden damage to your kidneys (a condition known as acute kidney injury), breakdown of muscle tissue that releases a damaging protein into your blood (a condition called rhabdomyolysis), and it could even lead to a cardiac arrest, causing your heart to suddenly stop beating.
- Seizure
- Changes in brain function
- Irregular fast heartbeat
- ECG (heart function test) changes
- Low blood potassium
- High blood sugar
- High body acid levels
- Acute kidney injury
- Breakdown of muscle tissue (rhabdomyolysis)
- Cardiac arrest
Recovery from Caffeine Toxicity
Due to the short period of effectiveness of caffeine, patients often return to normal as their caffeine levels decrease. Both neurological and heart changes have been seen to naturally resolve as caffeine leaves the body. Any irregularities in bodily salt levels should be corrected and these are not likely to happen again once caffeine levels return to normal.
Preventing Caffeine Toxicity
Caffeine is a common component in many products and is readily available without the need for a doctor’s prescription. However, it’s important to remember that caffeine can interact with various parts of the body, leading to serious side effects if consumed in large amounts. If caffeine toxicity occurs and is not treated promptly, it can lead to severe health problems and even death.
