Pharm: Ch 14: Drugs for the Treatment of Seizure Disorders, End of Chapter Questions & Case Study Answers
What is the approximate prevalence of seizure disorders in the general population?
1% of the population Seizure disorders are estimated to affect approximately 1% of the population, making it extremely likely that the dental team will encounter a patient with epilepsy. The drugs used to treat epilepsy are used chronically, with possible adverse effects that could alter dental treatment.
What are the dental concerns associated with carbamazepine and what should a parent be told about them?
A child takes this often 4 times daily and because of the high sugar content it will stick to the teeth and lead to the high probability of caries and recurrent caries as well as gingivitis in the mouth and mouth sores.
Fatal blood dyscrasias, including aplastic anemia and agranulocytosis, have been reported related to phenytoin therapy. Aplastic anemia occurs within 4 days and is most common in children.
Both statements are false Fatal blood dyscrasias, including aplastic anemia and agranulocytosis, have been reported related to carbamazepine therapy, not phenytoin therapy, and occur within 4 months among elderly adults taking it for trigeminal neuralgia. Higher doses of carbamazepine are given in treatment of trigeminal neuralgia, which may explain these phenomena.
Generalized seizures involve no loss of consciousness. Partial seizures cause a total loss of consciousness.
Both statements are false. Consciousness is lost in both types of generalized seizures, absence and tonic-clonic types. Partial seizures involve abnormal activity in only a part of the brain, with the location of the activity determining the signs and symptoms. When consciousness is not impaired, the attack is termed a simple partial attack. When consciousness is impaired, the attack is called a complex partial attack.
Clonazepam and clobazam used orally as anticonvulsant adjuvants. Diazepam, lorazepam, and midazolam used parenterally to treat recurrent tonic-clonic seizures or status epilepticus.
Both statements are true Benzodiazepines have many appropriate uses in the treatment of seizure disorders. Clonazepam (Klonopin) and clobazam (Onfi) are used orally as anticonvulsant adjuvants. Diazepam, lorazepam, and midazolam may be used parenterally to treat recurrent tonic-clonic seizures or status epilepticus seizures.
What are the major classes of adverse reactions associated with carbamazepine therapy?
CNS: dizziness, drowsiness, fatigue, confusion GI: nausea, vomiting, abdominal pain, diarrhea, constipation Oral: dry mouth, glossitis, stomatitis Hematologic effects CV: congestive heart failure and alteration in blood pressure.
From Homework: This drug is used in children and may be taken as a chewable that contains 63% sugar.
Carbamazepine (Tegretol) The drug is used to treat seizures, trigeminal neuralgia, & bipolar depression
Case Study: What may have been causing the increased incidence of caries in Sam?
Carbamazepine is often delivered 4 times daily in a 63% sugar chewable tablet. b Due to the high sugar content it will stick to the teeth and lead to the high probability of caries and recurrent caries as well as gingivitis in the mouth and mouth sores.
Case Study: What is carbamazepine and what is its role in treating seizure disorders?
Carbamazepine is structurally related to tricyclic anti-depressants and it is used to treat generalized tonic-cloning seizures, temporal lobe epilepsy, and mixed seizures.
What is carbamazepine and what is its role in treating seizure disorders?
Carbamazepine is structurally related to tricyclic anti-depressants and it is used to treat generalized tonic-cloning seizures, temporal lobe epilepsy, and mixed seizures. - the mechanism of action involved blocking sodium channels, which block the propagation of nerve impulses.
General adverse reactions of antiepileptic medications include all except:
Central Nervous System Excitation Anticonvulsant agents are central nervous system depressants, so central nervous system excitation is rare. General adverse reactions of antiepileptic medications include: ➡️ Dermatologic effects (erythema multiforme Steven-Johnson's syndrome) ➡️ Gastrointestinal distress ➡️ Central nervous system depression ➡️ Teratogenicity ➡️ or problems with fetal development, and withdrawal.
Discuss methods to minimize gingival enlargement.
DH should review proper brushing and flossing techniques. The pt should also be instructed to see his or her hygienist 4x a year instead of twice. The pt should also be instructed to contact his or her medical doctor if they continue to have issued with gingival hyperplasia.
The drug group of choice for the treatment of status epilepticus seizures is parenteral
Diazepam (Valium) Parenteral benzodiazepines such as diazepam (Valium) are the drugs of choice for treatment of status epilepticus. Status epilepticus seizures are continuous tonic-clonic seizures lasting more than 30 minutes, or seizures that recur before recovery from the previous seizure. Status epilepticus is an emergency situation, and rapid therapy is required to prevent possible brain damage and death.
What is the drug of choice for treatment of absence seizures?
Ethosuximide (Zarontin) The drug of choice for treatment of absence seizures is ethosuximide (Zarontin). It is not effective for treating partial seizures with complex symptoms or for treating tonic-clonic seizures. Gabapentin is used in treatment of complex partial seizures. Valproic acid is one of the first choices for treatment of tonic-clonic seizures. Phenobarbital is an older agent used alone or in combination with other drugs for treatment of generalized tonic-clonic and partial seizures.
From Homework: Tonic-clonic type of generalized seizures are also called?
Grand mal seizures
What is hirsutism? Why would this be a concern among girls and young women?
Hirsutism is characterized by hair growth over the body. Pt's taking phenytoin tend to develop hirsutism on the face and chest. This can be embarrassing for young women.
Case Study: What should a patient and parents or caregivers be told about the pediatric dose form of carbamazepine?
I would let them know of the 63% sugar content of the chewable tablet and let them know that they need to be highly aware of their child's oral hygiene. Teaching them ways and giving them pamphlets on how to teach and enforce better hygiene for their child.
What would you tell a parent about the pediatric dose form of carbamazepine?
I would let them know of the 63% sugar content of the chewable tablet and let them know that they need to be highly aware of their child's oral hygiene. Teaching them ways and giving them pamphlets on how to teach and enforce better hygiene for their child.
What is gingival hyperplasia and how can it be treated?
It is gum overgrowth which may occur shortly after the pt starts phenytoin to after several years of therapy. It is treated with good oral hygiene, reducing the dose of phenytoin, or changing to another antiepileptic drug. Gingivectomy should only be performed when hyperplasia interferes with plaque control, esthetics, or chewing or when oral hygiene has failed.
Discuss the role of valproate in the treatment of generalized tonic-clonic seizures. Include adverse effects and any impact on oral health care.
It is often used first in treating tonic cloinc seizures on the basis of the results presented in medical literature, although this use is not FDA approved. Adverse effects are GI, CNS, increased bleeding time. Additive bleeding is a risk; use caution in drugs that alter coagulation.
What are the dental concerns associated with the CNS adverse reactions of phenytoin?
It is sedating and the combo of phenytoin and drugs that are CNS depressants could make the pt even more sedated. Pts can also become confused, disoriented, dizzy, and may fall. Pts should be instructed about this and should avoid driving or anything that requires concentration.
Which antiseizure medication is associated with a syndrome causing congenital abnormality associated with maternal ingestion?
Phenytoin Fetal hydantoin syndrome is the term given to the congenital abnormality associated with maternal ingestion of phenytoin. The syndrome includes craniofacial anomalies, microcephaly, nail/digit hypoplasia, limb defects, growth deficiencies, and mental retardation. Thickening of facial structures and coarsening of facial features have also been noted.
Which antiseizure medication is most likely to cause gingival enlargement?
Phenytoin (Dilantin) An adverse reaction to phenytoin, gingival enlargement (previously known as gingival hyperplasia), occurs in approximately 50% of all chronic users. In about one third of affected patients, gingival enlargement is severe enough to require surgical intervention. The clinical symptoms of gingival enlargement may appear within a few weeks or as long as years after initial drug therapy. The better the patient's oral hygiene, the less likely the lesions are to occur or they will be less severe if they do occur.
What is the mechanism of action of phenytoin and what are its clinical uses?
Phenytoin is used to treat tonic clonic seizures and partial seizures with complex symptomatology, has also been used to treat trigeminal neuralgia. anticonvulsant Anticonvulsant may be useful in the treatment of generalized tonic-clonic status epileptics. The primary site of action appears to be the motor cortex where spread of seizure activity is inhibited.
Gabapentin (Neurontin) has been approved by the Food and Drug Administration (FDA) for control of seizures. Other indications for gabapentin include treatment of neuropathic pain.
The first statement is false; the second statement is true. Gabapentin (Neurontin) is FDA approved for the treatment of neuropathic pain. It is used "off label" for treatment of partial seizures.
Carbamazepine is better tolerated than lamotrigine in elderly patients who are newly diagnosed with partial or generalized seizures. Lamotrigine is better tolerated than ethosuximide in children with absence seizures.
The first statement is false; the second statement is true. Lamotrigine belongs to the class of sodium channel blocking antiepileptic drugs. Lamotrigine appears as effective as carbamazepine and better tolerated in elderly patients newly diagnosed with partial or generalized seizures. It is better tolerated than ethosuximide in children with absence seizures. Lamotrigine is FDA approved for maintenance therapy of bipolar disorder and may improve depression in some patients with epilepsy.
Case Study: What are the adverse effects associated with phenytoin therapy?
The most common adverse effects are lethargy, abnormal movements, mental confusion, and cognitive changes. Gingival hyperplasia is a well-known adverse effect of long-term oral phenytoin therapy. High level of dental home care can help prevent this. Other adverse effects associated with long-term phenytoin therapy can cause acne, hirsutism, and hypertrophy of subcutaneous facial tissue resulting in an appearance known as Dilantin facies and osteoporosis. Also: nystagmus, ataxia, drowsiness, rash, thrombocytopenia, and hepatitis.
Why should a parent be concerned about the pediatric dose form of carbamazepine?
The parent should be concerned because the medication 63% sugar in the chewable tablet.
Case Study: Are there any dental concerns associated with levetiracetam?
There does not seem to be any significant dental concerns with Levetiracetam. It may cause some somnolence, so caution should be used with other sedating medications.
Can any of the CNS adverse reactions affect oral health care?
They can be a concern if the medication is used in the dental office; pt may be sedated, confused, or dizzy. pts should be informed of this and advised against driving or doing anything that requires concentration.
From Homework: Which drug has a black box warning for it's hepatotoxicity?
Valproate (Depakote)
All are indications for carbamazepine (Tegretol) except:
muscle spasticity Carbamazepine (Tegretol) is not indicated for treatment of muscle spasticity. Indications for this drug include: ➡️ Treatment of seizure disorders ➡️ Trigeminal neuralgia (tic douloureux) ➡️ Bipolar depression.
Which is the most difficult aspect of treating patients with seizure disorders with regard to their medications?
chronic toxicity Drug therapy for treatment of epilepsy is usually long term, in many cases, throughout the patient's lifetime. Because of the long-term use of these drugs, chronic toxicity is a concern
Which is the mechanism of action of carbamazepine (Tegretol) in the treatment of epilepsy?
Blocking sodium channels, blocking nerve impulse propagation The action of carbamazepine (Tegretol) involves blocking sodium channels, blocking the propagation of nerve impulses, preventing seizures. Other effects of carbamazepine include the inhibition of high-frequency repetitive neuron firing and a decrease in synaptic transmission presynaptically.
Medications used for the management of seizure disorders include all except:
Amantadine (Symmetrel) Amantadine is not indicated for treatment of epilepsy. It is used to treat influenza and Parkinson's disease. Agents used in the prevention and management of seizures are: ➡️Carbamazepine (Tegretol) ➡️ Valproate (Depakote), ➡️ Phenytoin (Dilantin) ➡️ Clonazepam (Klonopin)
What is the role of the newer antiepileptic drugs, lamotrigine, levetiracetam, and oxcarbazepine, in the treatment of seizure disorders? What makes them more appealing than older drugs?
Lamotrigine: approved as an adjunct therapy for partial seizures, primary generalized tonic-clonic, and generalized seizures in Lennox-Gestaut syndrome in pts 2 years or older Levetiracetam: approved as an adjunct therapy for partial seizures in both adults and children 1 month and older for primary generalized tonic-clonic in adults and children 6 and older, and for myoclonic seizures in adults and children 12 and older. Oxcarbazepine: Monotherapy and adjunct therapy for partial seizures in adults and children 4 and up, adjunct therapy for partial seizures in children 2 and up. They are more appealing than older drugs because they are better tolerated. Lamotrifine and Levetiracetam have lower incidence of drug interactions.
Which is the primary advantage of oxcarbazepine compared to carbamazepine?
Less induction of hepatic enzymes Oxcarbazepine is chemically similar to carbamazepine, but it causes a lower induction of hepatic enzymes and does not induce its own metabolism. It is as effective as phenytoin, carbamazepine, and valproate for treatment of partial seizures and may be better tolerated. It has a long half-life of 8 to 10 hours.
Case Study: What is levetiracetam and what is its role in treating generalized tonic-clinic seizures?
Levetiracetam is a newer anti-seizure drug that is commonly used for the treatment of generalized tonic-clonic seizures.
What are some of the gastrointestinal adverse reactions associated with phenytoin?
NSAIDS and OPOIDS should be avoided. Nausea Vomiting gastric distress abdominal pain diarrhea constipation anorexia
Which would be appropriate dental management techniques for patients taking antiepileptic agents?
Only B applies: Take a thorough medical history, including medications and frequency of seizures. The appropriate dental management techniques for patients taking antiepileptic agents include reviewing emergency management of epileptic patients, taking a thorough medical and drug history including medications and frequency of seizures, and being aware of additive gastrointestinal adverse reactions such as nonsteroidal antiinflammatory drugs (NSAIDs) and drug interactions due to the induction of hepatic microsomal enzymes. Nothing should be placed in the mouth of a patient experiencing a seizure to avoid causing additional trauma, and caution should be used in prescribing antianxiety agents due to the additional risk of central nervous system (CNS) depression.
What should a patient be told about the concomitant use of an NSAID and phenytoin?
Patients should be instructed to take their medications after eating a meal, cracker, or bread or with a glass of milk. This should help minimize GI irritation.
Case Study: Discuss the adverse effects that may have led to Sam's inability to tolerate phenytoin.
Sedation and mental confusion could have led to his inability to tolerate phenytoin. Sam may have experienced nausea from his medication. He may have begun to experience gingival enlargement.
The most important drug interaction of the anticonvulsants involves
Stimulation of hepatic microsomal enzymes The most important drug interaction of the anticonvulsants involves stimulation of the hepatic microsomal enzymes, resulting in a reduction in the blood level of the affected drugs (those metabolized by the liver enzymes). Some other mechanisms of drug interactions include alteration of renal absorption or excretion and inducing or inhibiting metabolism.
From Homework: What is the most common type of seizure?
tonic-clonic (grand mal)
