Chapter 16 Flashcards
Anticonvulsants:
- epilepsy
- drug therapy of patients with epilepsy
- dental treatment of the patient with epilepsy
- Nonseizure uses of anticonvulsants
Epilepsy:
- generalized seizures
- Partial (focal) seizures
Nonseizure uses of anticonvulsants:
- Neurological pain
- Psychiatric pain
Define Epilepsy:
A group of disorders involving a chronic stereotype recurrent attack of involuntary behavior or experience or changes in neurological function caused by electrical activity in the brain that can be recorded via an electroencephalogram (EEG)
International Classification of Epileptic Seizures:
- Generalized Seizures
- Partial Seizures
- Miscellaneous
Generalized Seizures:
- Tonic Clonic
- Abscence
Partial Seizures:
- Simple
- Complex
Miscellaneous Seizures:
-Status epilepticus
Tonic Clonic Seizures:
- Loss of consciousness for longer period of time
- Major movement of large muscle groups
- Aura and postictal state
- Slow recovery
Drugs of choice for Tonic Clonic Seizures:
- Valproate
- Lamotrigine
- levetiracetam
Absence Seizures:
- Brief loss of consciousness
- Little movement
- Body tone is not lost
- No aura or postical state
- Quick recovery
Drug of choice for absence seizures:
Ethosuxumide
Status epilepticus:
- Continuous Tonic-Clonic Seizures that last longer than 30 minutes OR
- Recur before the end of the postical period of the previous seizure
- Emergency situation
- Parenteral benzodiazepines
- Diazepam (Valium)
Partial (Focal) Seizures:
- Involve activation of only part of the brain and the location of the activity determines the clinical manifestations
- Simple partial attack-Consciousness is not impaired
- Complex partial attack- consciousness is impaired; may have aura and slow recovery
Drug of choice for partial (focal) Seizures:
- Iamogotrigine
- Carbamazepine
- Levetiracetam
- oxcarbazepine
Drug therapy of patients with epilepsy: General Adverse Reactions
- Central nervous system depression:
- tolerance to sedative effects
- impaired learning and cognitive abilities
- hyperactivity and sedation
- Exacerbation of different seizure type
- Gastrointestinal distress-anorexia, nausea, or vomiting
- Drug interactions:
- Stimulation of hepatic microtonal enzymes
- More interactions with older drugs including phenytoin due to narrow TI
Drug therapy of patients with epilepsy: general adverse reactions, drug interactions, idiosyncratic reactions
- Dermatoligic side effects:
- Rash
- Stevens-Johnson’s syndrome
- Exfoliative dermatitis
- erythema mutliforme
- Drug-induced systemic lupus erythematosus
- Hematologic effects
- Teratogenicity/growth
- Withdrawal-abrupt withdrawal can precipitate a seizure
Valproate: Mechanism of Action
- Effect on Sodium and potassium channels
- Reduction in aspirate levels
- Increase in the inhibitory neurotransmitter gamma aminobutyric (GABA)
Adverse reactions of Valporate GI Effects:
- Indigestion, Nausea, Vomiting
- Hypersalivation
- Anorexia
- Increased appetite
- Cramping
- Diarrhea
- Constipation
Adverse reactions of Valproate CNS effects:
- Sedation and drowsiness
- Rarely: Ataxia, headache, nystagmus
- Hyperactivity, aggression, behavioral disturbances
- Weight gain
- Increased appetite
Adverse reactions of Valproate:
- Hepatotoxicity; liver function tests should be performed. Black box warning
- Prolonged bleeding time
- Teratogenicity
Drug interactions of Valproate:
- additive CNS depressant effect
- Inhibits the metabolism of phenobarbital > Excessive sedation
- Drug interactions with phenytoin > decrease Valproate action and Increased PHENYTOIN action
- Bleeding; prolongs bleeding time
Lamotrigine (Lamictal): uses
- Elderly Patients, newly diagnosed with partial or generalized seizures
- Children with absence seizures
- Bipolar disorder maintenance therapy
- Improved depression in patients with epilepsy
Lamotrigine (lactimal) Adverse Reactions:
- Dizziness
- ataxia
- somnolence
- headache
- dislopia
- nausea
- vomiting
- rash
- insomnia
- in coordination
- Steven-Johnson’s syndrome
Lamotrigine (lactimal): Drug interactions
-Carbamazepine reduces Lamotrigine levels
Valproate increases Lamotrigine levels
Levetiracetam (Keppra): uses
- Monotherapy for Partial- onset and generalized Tonic-Clonic Seizures
- Children with absence seizures
Levetiracetam (Keppra): Adverse Reactions
- dizziness
- somnolence
- weakness
- suicide ideation
- Agressive behavior
- Irritability
- Hostility
- Psychosis
- Steven-Johnson’s Syndrome
Carbamazepine (Tegretol)
- Related to tricyclic antidepressants
- Uses:
- Trigeminal neuralgia
- Bipolar depression
- Pharmilogical effects:
- Blocking sodium channels
- Inhibition of High-frequency repetitive firing in neurons
- Decrease in synaptic transmission
Carbamazepine (tegretol): Adverse Reactions, CNS effects
- Dizziness
- Vertigo
- Drowsiness
- Fatigue
- ataxia
- Confusion
- Headache
- Nystagmus
- Visual (diplopia) and speech disturbances
- Latent psychosis
- abnormal involuntary movements
- depression
- peripheral neuritis
Carbamazepine (tegretol): Adverse Reactions
- GI effects:
- Nausea, vomiting, gastric distress
- abdominal pain
- Diarrhea, constipation
- anorexia
- Hematologic effect:
- Fatal Blood dyscrasias such as aplastic anemia have been reported in the first 4 months of treatment of the elderly
Carbamazepine (tegretol): Adverse Reactions (Cont.)
- Dermatologic Effects:
- Rashes
- Urticaria
- Photosensitivity Reactions
- Altered skin pigmentation
- erythema multiforme
- erythema nodosum
- Aggrevation of systemic lupus erythematous
- Alopecia
Carbamazepine (tegretol): Adverse Reactions (cont.)
- Oral Effects:
- Dry mouth
- Glossitis
- Stomatitis
- Chewable Carbamazepine-63% sugar
Carbamazepine (tegretol): Drug interactions
- Carbamazepine can induce liver microsomal enzymes
- Decreases the effect of doxycycline, warfarin, theophylline, and oral contraceptives
- Effects may be increased by erythromycin, isoniazid, and calcium channel blockers
Phenytoin (Dilantin)
- Used to treat Tonic-Clonic and partial seizures
- GI Effects
- CNS Effects:
- Mental confusion, nystagmus,ataxia, slurred speech, blurred vision, diplopia, amblyopia, Dizziness, and insomnia
- Dermatologic Effects:
- Skin Reactions range from rash to exfoliate dermatitis, lupus erythematous, or Steven-Johnson’s syndrome
- Hypertrichosis on the trunk and face
Phenytoin (Dilantin): Adverse Reactions
Vitamin Deficiency: -Vitamin D and folate -Osteomalacia May result Teratogenicity/growth: -Fetal hydantion syndrome -craniofacial anomalies, microcephaly,nail or digit hypoplasia, limb defects, growth deficiency, and mental retardation -Thickening of facial structures
Phenytoin: Adverse Reactions
Gingival enlargement symptoms
- Often painless enlargement of the gingival margin
- interproximal papillae involvement
- Coalesce to cover occlusal surfaces of the teeth
- Occurs in approx. 50% of patients using the medication long term
- More common in anterior than posterior
- More common on buccal than lingual/palatial
- Rarely involves edentulous areas
- gingival does not bleed easily
Gingival enlargement:
-Drug induced gingival overgrowth is a side effect associated principally with 3 types of drugs: anticonvulsants (phenytoin), immunosuppressant (cyclosporine A), and various calcium channel blockers (nifedipine, verapamil, diltiazem)
Phenytoin: Adverse Reactions Gingival enlargement
- Unknown etiology
- Management:
- Choose another anti epileptic drug
- Discontinue phenytoin
- Improve oral hygiene
- Consider gingivectomy
- Consider other drugs
Miscellaneous Anticonvulsant Agents: Ethosuxumide (Zarontin)
- Mechanism of action: Inhibiting the T-type calcium channels
- GI Adverse Effects: Drowsiness, hyperactivity, headache, and hiccups
- Blood dycrasias, systemic lupus erythematous, Steven Johnson’s syndrome, hirsutism, gingival enlargement, and swelling of the tongue
Miscellaneous Anticonvulsant Agents: Benzodiazepines
- Clonezepam (Klonopin) uses:
- Absence Seizures not responsive to ethosuximide
- Mental Illnesses
Anti epileptic Agents:
Gabapentin (Neurontin)
- Mechanism of Action: GABA analog but does not interact with GABE receptor
- Use: adjunct treatment of partial seizures, with and without generalized in adults and children 3 years of age and older
- Adverse Reactions: Somnolence, Dizziness, fatigue, ataxia, nystagmus, blurred vision, and confusion. Edema weight gain and movement disorders have been reported.
Nonseizure Uses of Anti-epileptics:
- Chronic Pain Management (Neurontin)
- Trigeminal Neuralgia (Carbamazepine
- Migraine Headache Prophylaxis (Valproice Acid)
Dental treatment of the patient with Epilepsy:
Preventive measures: -Detailed Seizures history -Thoughtful treatment planning -Education of entire staff Management: -Move patient to the floor if possible -Tilt Patients head to one side -Remove objects from the Patients mouth
