What is Calcium Channel Blocker Toxicity?
Calcium channel blockers (CCBs) are a type of medication that are very often used to treat heart-related issues in adults. They’re used for various health conditions, such as high blood pressure, a fast heartbeat that starts in the upper parts of the heart (known as supraventricular tachycardia), spasms of blood vessels (vasospasm), and migraine headaches.
What Causes Calcium Channel Blocker Toxicity?
Consuming too much of certain substances, whether it’s by accident, intentionally for a harmful purpose, or out of children’s curiosity, can cause serious harm to the body. The same applies to using medications for treatment. It can be risky, especially when mixed with other heart medications or if something affects how the body processes or removes these medications.
Poisoning from these sources can majorly impact the body’s blood circulation and could even be life-threatening.
Risk Factors and Frequency for Calcium Channel Blocker Toxicity
Heart medication is one of the fastest-growing categories of substances that people are accidentally or intentionally exposed to, according to American Poison Control Centers. In 2011, there were 11,764 reported overdoses in adults with calcium channel blockers (a type of heart medication), making it the second most common medication after beta-blockers to cause overdose deaths. Unfortunately, 78 deaths were reported from heart medication overdoses. The two types of heart medications that caused the most deaths were calcium channel blockers and beta-blockers. Specific drugs, like Verapamil and Propranolol, were often involved in these instances. However, it’s important to remember that many cases might be unreported.
Signs and Symptoms of Calcium Channel Blocker Toxicity
If someone accidentally consumes an excessive amount of calcium channel blockers (medications for cardiovascular conditions), their reaction could range from no noticeable effects to immediate issues with their cardiovascular system and even sudden death. These reactions depend on factors like the person’s age, overall health, whether they’ve taken any other heart-related medications, and how detrimental the overdose was.
Usually, an unhealthy dosage of fast-acting calcium channel blockers will start to show symptoms within 2 to 3 hours, and no later than 6 hours after ingestion. However, if sustained-release versions of these medications are taken in high amounts, the onset of toxicity could delay up to 16 hours.
Early signs of an overdose can be relatively vague, including symptoms such as dizziness, fatigue, and lightheadedness. In severe cases, the situation may quickly worsen, leading to mental confusion, coma, and even life-threatening shock.
- Dizziness
- Fatigue
- Lightheadedness
- Confusion or altered mental status
- Coma
- Potential for fatal shock or sudden cardiovascular collapse
Testing for Calcium Channel Blocker Toxicity
- ECG (Electrocardiogram) provides insight into a person’s heart function. Commonly noted abnormalities after a person ingests calcium channel blockers (medications that relax and widen blood vessels) include a slow heart rate, different degrees of interruptions in the communication between the chambers of the heart (atrioventricular blocks), a delay or blockage in the flow of electrical impulses that regulate the heartbeat (bundle branch block), a longer time for electrical signals to travel through the heart (QT prolongation), and irregular heartbeats that originate in the junctions between the heart’s upper chambers and lower chambers (junctional rhythms). Dihydropyridines, a specific type of calcium channel blocker, usually maintain regular heart rhythm but might cause an abnormally fast heart rate.
- Low blood pressure and a slow heart rate can progressively worsen, potentially leading to a state of shock where the heart is not pumping enough blood (cardiogenic shock). Elevated sugar levels in the blood are also common with all types of calcium channel blockers, which can be helpful for assessing the severity of poisoning. Both these conditions can lead to a condition where the body produces excessive acid (metabolic acidosis). It is also common for people to have low potassium levels (mild hypokalemia) and low calcium levels (mild to severe hypocalcemia) in the blood.
- In cases of a severe overdose, reduced blood flow (profound hypoperfusion) and lack of blood supply to the organs (end-organ ischemia) can cause symptoms of organ failures, such as seizures, heart attacks, severe lung disease (acute respiratory distress syndrome/ ARDS), kidney failure, bowel death from lack of blood supply, and stroke.
- There are only a few reports of fluid build-up in the lungs not related to heart problems (non-cardiogenic pulmonary edema), due to calcium channel blocker overdose and the cause is not clearly understood. It could be related to sudden widening of blood vessels near the skin’s surface causing increased pressure in the capillaries. Overly aggressive use of fluids (crystalloids) to treat low blood pressure might make the condition worse.
Treatment Options for Calcium Channel Blocker Toxicity
When a patient is critically ill, their care primarily focuses on ensuring their airway is clear, they can breathe adequately, and that their blood circulation is maintained. In some situations, where a patient’s condition might deteriorate rapidly, an intervention called endotracheal intubation can be considered. This involves placing a tube into the person’s airway through the mouth or nostril.
If a situation doesn’t seem to be worsening immediately, the patient’s heart function should still be monitored closely in a critical care setting. This type of care typically involves asking the patient about their medical history, understanding the type of substances ingested and when they were taken. An ECG (or electrocardiogram) test may also be performed to look for any irregularities in the heart’s electrical activity.
As part of the initial care, fluids are usually given via an intravenous drip to help support the patient’s blood circulation. However, it is important to be mindful of giving too much fluid, especially if the heart’s pumping function is impaired. In these instances, monitoring changes in certain parameters of heart functionality can be useful.
If you’re dealing with a medical emergency like this, it’s important to promptly seek guidance from a medical toxicologist or poison control center. Given the likelihood of needing a pacemaker or other heart assistance in severe overdose cases, a cardiologist should also be consulted.
This situation can be further complicated because the standard ways doctors normally remove toxins from the body, like urinary alkalinization, hemodialysis, or hemofiltration may not be effective in this scenario due to the nature of the ingested substance. In these cases, a technique known as whole bowel irrigation, which flushes out the intestines, may be the primary way of removing the ingested substance from the body.
Despite this, there is some debate about whether detoxing the stomach and intestines is useful for patients, particularly when treatment is received early after ingestion. It’s widely agreed that the priority should be stabilizing the patient first before attempting detoxification, particularly if the patient is unstable.
Once the patient is stable, one option for detoxification is activated charcoal, which is often administered within 1 to 2 hours for maximum effectiveness. In previous studies, this method has shown to reduce the absorption of the ingested substance by roughly half when administered 2 hours after ingestion.
There are a number of different medications available to treat cases like this. The approach for each patient usually depends on their specific situation. In some cases, these treatments involve administering calcium, insulin, methylene blue, intravenous lipid, glucagon and other medications depending on how severe the poisoning is. Each of these medications work in different ways to counteract the effects of the ingested substance and support a patient’s recovery.
In severe cases where medication isn’t successful, other non-drug interventions might be necessary. These might include advanced heart support interventions available in intensive care, such as using a pacemaker or other devices to assist the heart’s function. In extremely severe scenarios, a process known as extracorporeal membrane oxygenation might be necessary, which is a way of providing longer-term support to the heart and lungs.
Once patients are stable, they may be referred to mental health professionals for further evaluation and care. This is particularly important if the ingestion was intentional, as part of a suicide attempt, for example.
What else can Calcium Channel Blocker Toxicity be?
: Beta-blockers, a type of medicine, can have effects similar to calcium channel blockers (CCBs). Often, beta-blockers are preferred over CCBs as they are less likely to cause high blood sugar levels in adults.
However, if someone exhibits symptoms of a slow heart rate (bradycardia) and low blood pressure (hypotension), it’s important to consider other medicines that could cause these symptoms, including:
- Beta-blocker toxicity
- Toxicity from tricyclic antidepressants
- Digoxin toxicity
- Clonidine overdose
- Sedative-hypnotic toxicity
- Opiate overdose
- Organophosphate poisoning
What to expect with Calcium Channel Blocker Toxicity
The outlook after toxicity greatly depends on the amount of harmful substance ingested, the severity of the toxic reaction, and how badly it has affected the organs in your body.
Several factors can make the prognosis worse, including:
- Being older in age
- Already having heart problems
- Failure of multiple organs in your body
- Severe and persistent shock that requires advanced treatment methods – like a process called extracorporeal membrane oxygenation (ECMO), which is basically an outside-of-body technique to provide oxygen to your blood.
Possible Complications When Diagnosed with Calcium Channel Blocker Toxicity
The problems that can arise from poisoning can vary. They can be from the poisoning itself, or from the treatment methods used to save a life.
Problems from the poisoning can include:
- Cardiogenic and distributive shock that are not responsive to treatment
- Acute respiratory distress syndrome (ARDs), a severe lung condition
- Severe decrease in blood flow, leading to injuries such as bowel injury, heart attack, kidney disease, and limb death
- Cardiac arrest with pulseless electrical activity (PEA)
Problems from the treatment for the poisoning can include:
- Multiorgan failure due to calciphylaxis from excessive calcium infusion
- Low levels of potassium and sugar in the blood with HIET treatment
- ARDS, high triglyceride levels, pancreatitis, and fat overload syndrome from lipid emulsion therapy
- Nausea, vomiting, intestinal obstruction, and low potassium levels with glucagon
- Blood clots and limb ischemia from interventions like ECMO
Preventing Calcium Channel Blocker Toxicity
Calcium channel blockers are a type of medicine used to treat various health conditions including high blood pressure, rapid or irregular heartbeat, bluish discoloration and cramping of the fingers, or headaches. Some common medicines in this category include verapamil, amlodipine, nifedipine, and diltiazem.
Like most other medicines, these can be harmful and lead to a wide array of serious problems, including life-threatening ones, if taken more than the recommended dose.
Also, sometimes, if your body has trouble breaking down medicines or if these drugs interact with other medicines you’re taking, they can build up in your body and cause harm.
If you have any concerns about taking too much or if you start to feel unusual symptoms, you should seek medical help immediately.
If you don’t have severe symptoms or any symptoms at all, it’s always best to check and ensure your safety. Help is just a phone call away through the poison control center. The 24/7 helpline in the US is 800-222-1222.
If you start to feel dizzy, lightheaded, confused, or nauseous, you should head to the emergency room right away. In such cases, getting help quickly can save lives.
In the long term, it’s important to make sure your home is safe, particularly when it comes to managing medicines. You should supervise when older adults are taking their medicines. Individuals with suicidal thoughts or depression should seek mental health support.
