Anesthesia, Pain, and Seizure Drugs

phenobarbital (Luminal)
Class:
Barbiturates

Mechanism of action:
Potentiate the action of GABA, thus, depressing the firing of CNS neurons

Uses:
Used for all types of seizures except absence seizures

AE:
-Dependence, drowsiness, vitamin deficiencies, laryngospasm, somnolence, FALL RISK, respiratory depression, CNS depression, coma, death

Considerations:
-SHORT TERM USE ONLY B/C OF DEPENDENCY
-Monitor for liver and kidney fxn to avoid overdose
-PREGNANCY CAT D, use alternate contraception
-Low margin of safety!
-report drowsiness, bone pain, excessive bleeding

diazepam (Valium)-long acting

clonazepam (Klonopin)

lorazepam (Ativan)

research which one is long acting and short acting
diazepam and lorazepam parenteral admins for termination of status epilepticus

Class:
Benzodiazepines

Mech. of action:
Bind directly to GABA receptor, suppressing abnormal neuronal foci
-similar to barbiturates but safer

Uses:
short-term seizure control
-indications: absence seizures and myoclonic seizures
-also for anxiety, skeletal muscle spasms, alcohol withdrawals

AE:
drowsiness and dizziness–fall risk, ataxia, respiratory depression, coma
-laryngospasm, CV collapse

Considerations:
-SHORT TERM USE ONLY
-HIGH RISK FOR ADDICTION AND TOXICITY BUT NOT AS BAD AS BARBITURATES
-best taken with food!!
-benzodiazepines and barbiturates discouraged for geriatric use
-avoid alcohol, OTC drugs, herbal meds, nicotine
-avoid driving/hazardous activities
-rebound seizures if d/c abruptly
-be wary of illegal use/drug abuse
-CONTRAINDICATED FOR NARROW ANGLE GLAUCOMA
-CAT D pregnancy
-GIVE flumazenil (Romazicon) for benzodiazepine overdose
-DO NOT STOP ANTISEIZURE MEDS ABRUPTLY
-THE ONLY MED USED AS RELIEVER FOR ACTIVE SEIZURES/EMERGENCY SEIZURES

phenytoin (Dilantin)
Class:
Hydatoins

Mech. of action:
desensitization of sodium channels

Uses:
-Tx all type of epilepsy except absence seizures

AE:
CNS depression (somnolence, drowsiness, dizziness, nystagmus), gingival hyperplasia (can harbor bacteria), skin rash, cardiac dysrhythmias, hypotension

Considerations:
-monitor serum-drug levels (FOR ALL SEIZURE MEDS)-narrow therapeutic range
-monitor s/sx of toxicity.
-monitor blood dyscrasias and bleeding disorders due to effects on platelets
-monitor liver and kidney fxn
-Can cause hepatotoxicity, monitor liver fxn tests
-less risk of sedation and dependence compared to barbiturates, but these are still concerns
-contraindicated for rash, seizures due to hypoglycemia, sinus bradycardia, and heart block
-drug dosage must be individualized due to differences in metabolism of this drug