What are signs and symptoms of Phenytoin Toxicity?

The signs and symptoms of Phenytoin Toxicity can vary depending on the severity of the condition. Some common signs and symptoms include: 1. Nystagmus: This is an involuntary movement of the eyes, which can cause rapid and jerky eye movements. 2. Ataxia: Phenytoin Toxicity can lead to problems with coordination and balance, resulting in unsteady movements and difficulty walking. 3. Slurred speech: Phenytoin Toxicity can affect the muscles involved in speech, leading to difficulty in articulating words clearly. 4. Confusion: Patients with Phenytoin Toxicity may experience confusion, disorientation, and difficulty concentrating. 5. Dizziness: Dizziness and lightheadedness can occur as a result of Phenytoin Toxicity. 6. Tremors: Some individuals may experience tremors or shaking of the hands or other parts of the body. 7. Seizures: Paradoxically, Phenytoin Toxicity can also cause seizures, which is ironic considering that phenytoin is an antiepileptic drug. It is important to note that these signs and symptoms can be similar to those of other medical conditions, so it is crucial to consult a healthcare professional for an accurate diagnosis.

How do you get Phenytoin Toxicity?

There are several risk factors for Phenytoin toxicity, including changes in medication, changes in physical condition, accidental overdose, long-term use, DRESS syndrome, and Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis.

What else can Phenytoin Toxicity be?

Barbiturate toxicity, Benzodiazepine toxicity, Carbamazepine toxicity, Encephalitis, Erythema multiforme, Isoniazid toxicity, Shock, Stevens-Johnson syndrome, Systemic Lupus Erythematosus (SLE), Toxic epidermal necrolysis.

What kinds of test are needed for Phenytoin Toxicity?

The types of tests needed for Phenytoin Toxicity include: - Fingerstick test to check sugar levels - Pregnancy test for women who could be pregnant - ECG to check heart function, especially if directly injected with phenytoin - Complete blood count (CBC) to check different types of cells in the blood - Basic metabolic panel (BMP) to check glucose level, kidney health, electrolyte and fluid balance - Liver function test (LFT) to assess liver health and its role in processing drugs like phenytoin - Measurement of phenytoin level in the blood - Measurement of albumin level in the blood - Urine sample for toxicology test to identify other harmful substances in the body - Other tests may be done to assess breathing, heartbeat, blood pressure, and manage side effects such as seizures and nausea.

How is Phenytoin Toxicity treated?

Phenytoin toxicity is managed through various treatment approaches. The first step is to ensure the patient's safety and stability by checking their breathing, heartbeat, and blood pressure. Hypotension (low blood pressure) can be treated with a large amount of solution or medications like norepinephrine or dopamine. Bradycardia (slow heart rate) can be managed with medicines such as atropine and epinephrine or devices that control the heartbeat. Other side effects like nausea and vomiting are treated according to standard medical guidelines. Seizures can be controlled with medications like benzodiazepines, phenobarbital, or levetiracetam. Activated charcoal can be used to prevent the absorption of phenytoin, but only if the patient is fully alert and conscious. Hemodialysis may be considered in severe cases, but its benefits are not fully proven and it is usually used after consulting with a specialist.

What are the side effects when treating Phenytoin Toxicity?

The side effects when treating Phenytoin Toxicity include: - Confusion - Hallucinations (seeing or hearing things that are not there) - Damage to nerves in the body (Neuropathy) - Accidental falls - Brain dysfunction (Encephalopathy) - Inability to control urine (Urinary incontinence) - Abnormal body movements (Movement disorders) - Prolonged and painful erections (Priapism) - Skin rash - High blood sugar levels (Hyperglycemia) - Low blood sugar levels (Hypoglycemia)

Are there long term effects of Phenytoin Toxicity?

The prognosis for Phenytoin Toxicity depends on the severity of the overdose and the individual patient's response to treatment. In cases of mild to moderate overdose symptoms, normal mental functionality, and normal heart rhythms, patients can be safely admitted to a hospital ward without the need for continuous heart monitoring. If the drug levels are decreasing and the patient can walk unaided, they may be safely discharged home with appropriate follow-up care.

What type of doctor should I see for Phenytoin Toxicity?

A specialist or a doctor who is knowledgeable in toxicology or neurology.

Phenytoin Toxicity

What is Phenytoin Toxicity?

Phenytoin, a medication discovered in 1908, has become one of the most extensively researched medicines used to control seizures. With a normal monthly cost of around $30, it is also one of the most commonly used seizure medications and is included on the World Health Organization’s List of Essential Medicines. However, because this drug has a narrow range between effective doses and potentially harmful ones, and it’s used daily by many people, it’s vital to be aware of the possible risks of an overdose or long-term use. Understanding these risks helps ensure early treatment and prevents the likelihood of further harmful effects from the drug.

What Causes Phenytoin Toxicity?

Phenytoin is a medication used to control seizures. However, it can become toxic in the body due to several factors, which can put your health at risk. Here are some of the common risk factors for Phenytoin toxicity:

Changes in Medication: Increasing your daily dose of phenytoin, switching to different brands or formulations, or changing how often you take it can lead to toxicity. If you start a new medication, it might interact with phenytoin, causing problems. Phenytoin is broken down by enzymes in your liver, which certain medications can interfere with.

Changes in Physical Condition: Certain health conditions could cause the level of phenytoin in your blood to change. Conditions like cirrhosis (liver disease) can decrease a protein called albumin in your blood, which can lead to more phenytoin in your blood. Kidney disease can also decrease albumin levels, while a condition called uremia can reduce the amount of bound phenytoin in your blood. Other factors like malnutrition, cancer, or pregnancy can also cause phenytoin toxicity, even without increasing your dosage.

Accidental Overdose: Taking too much phenytoin at once can cause toxicity. This can happen accidentally or intentionally. There have also been cases of crack cocaine being mixed with phenytoin, leading to an unintentional overdose.

Long-term Use: Over time, taking phenytoin can contribute to certain conditions. One issue is abnormal gum growth, possibly due to how the drug affects gum cells. Other factors that can contribute include hormone imbalance, changes in calcium metabolism, low levels of folic acid, and a weakened immune system.

DRESS Syndrome: DRESS syndrome is an uncommon but serious reaction to chronic phenytoin use. It’s rare but can result in a high fever, a rash, and throat inflammation. Misdiagnosis is common, as it can mimic a strep throat. It can also affect other organs like the liver and kidneys, and in some cases, can be fatal. If DRESS syndrome is suspected, phenytoin should be immediately discontinued, and a steroid treatment will usually be started. A skin biopsy may be needed for diagnosis, and an alternative anticonvulsant without the problematic chemicals should be used instead.

Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: Phenytoin has been associated with both Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), which are severe skin reactions. People with specific genetic traits, particularly in Asia, are at higher risk. If a rash develops, stop taking phenytoin immediately and consult your doctor. Genetic testing may be advised before switching to a different anticonvulsant.

Risk Factors and Frequency for Phenytoin Toxicity

Based on the 2011 report by the American Association of Poison Control Centers, there were 1,971 cases of exposure to a substance called phenytoin. This led to 46 severe health issues and one fatality.

Testing for Phenytoin Toxicity

If your doctor suspects that you may have overdosed on a medicine called phenytoin, they will have to run a number of tests to be sure. They need to consider a whole range of other possible causes for your symptoms. One of the first things they’ll do is check your sugar levels with a small fingerstick test. If you’re a woman who could be pregnant, they’ll also want to do a pregnancy test.

Another important test they’ll do is called an ECG, which is a way of checking how your heart is working. This is especially crucial if you’ve been directly injected with phenytoin.

Your doctor will also need to take some blood to run a variety of tests. One is a complete blood count (CBC), which checks different types of cells in your blood. A basic metabolic panel (BMP) is a broader test that checks a variety of things like your glucose level, kidney health, and electrolyte and fluid balance. They’ll also do a liver function test (LFT) as your liver plays a key role in processing drugs like phenytoin. Furthermore, they’ll also look at the actual level of phenytoin in your blood and check the level of a protein called albumin, which can affect how phenytoin acts in your body.

Finally, they’ll need a urine sample to complete a toxicology test. This can help to identify other possibly harmful substances in your body, including drugs like acetaminophen (also known as paracetamol), salicylic acid (a key ingredient in many pain relievers), and alcohol. These can all potentially interact with phenytoin and affect how your body responds to it.

Treatment Options for Phenytoin Toxicity

Phenytoin toxicity (having too much of the drug phenytoin in your body) does not have a specific cure, but it can be managed. The first step in dealing with this condition is to ensure that the patient is safe and stable. This includes making sure that the patient can breathe properly and checking their heartbeat and blood pressure.

If someone’s blood pressure is too low (a condition called hypotension), it can be treated with a solution that is given in large amounts at once. If their blood pressure doesn’t return to normal, they may be given medications like norepinephrine or dopamine. If someone’s heart rate is too slow (a condition called bradycardia), it can be managed with medicines such as atropine and epinephrine, or in some cases, with devices that help control the heartbeat.

Other side effects of having too much phenytoin in the body, like feeling sick or vomiting, can be treated according to standard medical guidelines. Seizures, in particular, can be controlled with medications like benzodiazepines, phenobarbital, or levetiracetam.

Activated charcoal, a substance that can bind to phenytoin and prevent it from being absorbed by the body, can also be useful, especially after taking a large dose of the drug. However, it should not be used if the patient is not fully alert and conscious. The use of multiple doses of activated charcoal remains a matter of debate, and methods that force the body to get rid of the drug, like induced vomiting or certain cleansing techniques, are not recommended.

While removing the drug from the blood through a process called hemodialysis could theoretically help treat phenytoin toxicity, its benefits are not fully proven and it is usually only used in severe cases, and after consulting with a specialist. In fact, one group of experts suggests considering hemodialysis only in cases of coma or severe lack of coordination (a condition called ataxia), but not based on the amount of phenytoin alone in the blood.

Remember, if you think you or someone else may have taken too much phenytoin, it’s important to get medical help right away.

These are some of the medical conditions that could be mistaken for each other because their symptoms can be similar:

Barbiturate toxicity
Benzodiazepine toxicity
Carbamazepine toxicity
Encephalitis
Erythema multiforme
Isoniazid toxicity
Shock
Stevens-Johnson syndrome
Systemic Lupus Erythematosus (SLE)
Toxic epidermal necrolysis

Remember, although the symptoms can look the same, the underlying causes are different. Therefore, it’s important to get a correct diagnosis.

What to expect with Phenytoin Toxicity

Deaths due to the ingestion of phenytoin, a medication used for certain types of seizures, are uncommon when taken alone. Most fatal cases have been associated with the intake of other substances alongside phenytoin. Cases that do result in death usually involve high concentrations of the medication in the bloodstream – more than 125 mg/L.

Each patient is treated according to their unique situation. Those requiring assistance with breathing, those who are unstable from a blood pressure standpoint, or those with abnormal heart rhythms (as shown on an electrocardiogram, a test that measures electrical activity of the heart) should be admitted to a hospital ward where they can be closely monitored.

Patients who have mild to moderate overdose symptoms, normal mental functionality, and normal heart rhythms without any low blood pressure, slowed heartbeat, or irregular heartbeats can safely be admitted to a hospital ward without the need for continuous heart monitoring.

Testing for the level of phenytoin in the blood should be repeated and tracked over time. If the drug levels are decreasing and the patient can walk unaided, and there is a caregiver at home who can assist with daily routine activities until all the overdose symptoms are resolved, they may be safely discharged home. Arrangements should be made for appropriate follow-up care. Any patient who has intentionally overdosed should have a mental health assessment while in the hospital.