Canadian National Institute of Health inc. Anticonvulsants L.O. 16 chapter 16, pg.213 Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Epilepsy Group of disorders characterized by recurrent episodes termed seizures. These are due to abnormal electrical discharges in the brain, recorded on EEG. Seizures may be accompanied by involuntary motor activity (convulsions) or other neurologic changes (sensory or emotional) Treated with anticonvulsant medication, usually for life Adjuvant medication: benzodiazepines, phenobarbital Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Epilepsy Causes: Idiopathic (majority) genetic cancers trauma infections toxicity to exogenous agents Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Epilepsy Classification: Partial seizures (activity only in one part of the brain): simple seizures (without loss of consciousness) complex seizures (loss of consciousness) Generalized seizures: absence seizures = petit mal (usually partial loss of consciousness) tonic-clonic seizures = grand mal (complete loss of conscious.) Miscellaneous seizures Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Absence seizures Begins in childhood and disappear in middle age. Patient usually unaware of the occurrence of seizure, body tone is not lost, patient quickly returns to normal activity (few seconds). Treatment: valproic acid, ethosuximide Risk for the dental team: drug interactions and adverse reactions Canadian National Institute of Health inc.

Tonic-clonic seizures (grand mal) Longer periods of loss of consciouness Major motor activity of large muscles tonic rigidity of the muscles followed by clonic jerking of the face, limbs and body Patient falls to the floor Might bite lips, tongue. Injury to self Finally becomes limp and comatose Consciousness returns gradually, followed by confusion, headache, drowsiness Treatment: valproic acid, phenytoin, phenobarbital, carbamazepine Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Partial seizures Last several minutes Abnormal activity in only one part of the brain, with symptoms different according to location of activity Simple (elementary) attack: conscious Complex (psychomotor, temporal-lobe seizure): unconscious, may have an aura, consciouness is slow to return. Treatment: carbamazepine, phenytoin, phenobarbital, primidone Canadian National Institute of Health inc.

Anticonvulsant agents Are CNS depressants that attempt to prevent seizures without causing excessive drowsiness. Prevent the spread of abnormal electric discharges in the brain. Mechanism of action not completely known. Single or combination Narrow therapeutic index Usually taken for life; chronic toxicity Complete control of seizures (difficult to achieve), or just reduce frequency Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Adverse reactions CNS depression: Impaired learning. Behavior alteration: hyperactivity or sedation exacerbation of a seizure type that is not being treated. Additive with other CNS depressants; opioids, reduce opioid dose. Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Adverse reactions GI tract: Anorexia, nausea, vomiting Minimize these effects by taking the drug with food Avoid other agents with similar GI effects; NSAIAs and opioids Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Adverse reactions Dermatological effects: rash, exfoliate dermatitis, erythematic multiform, Stevens-Johnson syndrome(target lesions) drug induced systemic lupus erythematous Hematologic effects: anemia from folic acid and B12 vitamine deficiency bleeding because of platelet aggregation inhibition Teratogenic Withdrawal: abrupt discontinuation of medication will precipitate seizures Canadian National Institute of Health inc.

Oral adverse reactions Gingival enlargement; phenytoin, ethosuximide Dry mouth: carbamazepine Glossitis, stomatitis, ulcerations for phenitoin (due to folate deficiency), carbamazepine (dry mouth) Mucositis; gabapentin(newer anticonvulsant) Caries in children using chewable carbamazepine due to high content of sugar (63%) Increased bleeding times: valproates inhibit platelet aggregations Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Gingival enlargement Cause is unknown Affects ~50% of chronic users In about 30% of affected patients is severe enough to require surgical removal Symptoms appear after few weeks of –few years of treatment Most affected areas: anterior region, buccal side Influenced by OH Younger patients are more affected Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Gingival enlargement Management: in consultation with patient’s physician Switch to another effective antiepileptic drug Substitute ethotoin for phenytoin if possible Discontinue phenytoin; decrease in gingival enlargement over a 1-year period. Wait with surgical intervention for at least 18 month after therapy is discontinued. Improve OH Gingivectomy; regrowth of gingiva with continuation of drug therapy Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Drug interactions Stimulation of hepatic enzymes, resulting in reduced blood levels of some drugs that are metabolized by the liver Interactions with other anticonvulsant medications Narrow therapeutic index, so if level of anticonvulsant medication is altered by drug interaction, either toxicity or loss of seizure control will result. Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Phenytoin (Dilantin) Treatment of tonic-clonic and partial seizures Was used to treat trigeminal neuralgia Has quinidine-like antiarrhythmic properties Adverse reactions: narrow therapeutic index Associated with gingival enlargement Nausea, confusion, insomnia, vit.D and folate deficiency: oral ulcers, glossitis Canadian National Institute of Health inc.

Management of patients taking phenytoin (Dilantin) If nausea is present, avoid drugs that are gastric irritants Monitor for gingival enlargement Administer folic acid if necessary Provide extensive OHI Schedule more frequent oral prophylaxis appointments Canadian National Institute of Health inc.

Carbamazepine (Tegretol) Related structurally to tricyclic antidepressants Treat of epilepsy, bipolar depression, trigeminal neuralgia Side effects; CNS(confusion, fatigue, headache), GI(nausea, vomiting), hematologic (blood dyscrasias, can be serious: anemia, agranulocytosis, thrombocytopenia, leukopenia. Lab tests. Observe oral cavity for petechiae or infections) Oral side effects; xerostomia, caries for children on chewable tablets Canadian National Institute of Health inc.

Management of patients taking carbamazepine (Tegretol) Check for xerostomia, glossitis, stomatits Avoid drugs that can alter coagulation: additive bleeding Look for symptoms of blood dyscrasia Drug interactions: doxycycline has reduced effect, erythromycin increases carbamazepine’s effect OHI and F as necessary for child on chewable carbamazepine tablets Canadian National Institute of Health inc.

Canadian National Institute of Health inc. Valproic acid Adverse reactions: nausea and vomiting Sedation and drowsiness Hepatotoxicity, can be serious. Test hepatic function Bleeding; inhibits platelet aggregation. Caution with other drugs that promote bleeding Canadian National Institute of Health inc.

Management of patients taking valproic acid (Depakote) Caution in using other drugs that can alter coagulation; additive bleeding Look for signs of hepatotoxicity Canadian National Institute of Health inc.

Management of patients with epilepsy Education of entire dental team Detailed seizure history Treatment planning for low stress, patient not to miss medication If tonic-clonic seizure occurs: Place patient on the floor if possible. Or dental chair to horizontal. Tilt head to prevent aspiration Remove objects from mouth before seizure to prevent tooth fracture Do not use tongue blade, as can split and produce oral trauma Canadian National Institute of Health inc.

Non-seizure uses of anticonvulsants Neurologic pain: Carbamazepine for trigeminal neuralgia and atypical facial pain Phenytoin was use for trigeminal neuralgia Valproic acid for migraine headache prophylaxis Psychiatric use: Carbamazepine, valproic acid, clonazepam, gabapentin as mood stabilizers for bipolar disorder. A patient on anticonvulsant medication does not necessarily have a seizure disorder, but a neurologic or psychiatric diagnostic Canadian National Institute of Health inc.