PHARM CHAPTER 11 2008

DRUGS FOR SEIZURES

Chapter 11

INTRODUCTION Epilepsy is a

common disorder of the CNS characterized by symptoms of blackout, fainting spells, apparent clumsiness, temporary loss of memory, and/or irregular seizure activity.

INTRODUCTION Over two million

Americans have epilepsy, and except for when these symptoms are expressed, most of the time it appears that their health is not challenged.

SEIZURES & CONVULSIONS ARE SYMPTOMS OF EPILEPSY Seizures—abnormal or

uncontrollable neuronal discharges within the brain.

May cause a blank stare, a loss of consciousness, jerking body movements, or a period of general confusion for the client.

SEIZURES & CONVULSIONS The terms

convulsion and seizure are not the same.

Convulsions specifically refer to involuntary, violent spasms of the large skeletal muscles of the face, neck, arms, and legs.

SEIZURES & CONVULSIONS All convulsions are

seizures, but not all seizures are convulsions.

Although some types of seizures do indeed involve convulsions, other seizures do not.

Thus antiseizure meds rather than anticonvulsants.

CAUSES Neuronal damage or

injury Head trauma Extreme fever Heat exhaustion Brain tumor Infections Stroke

Lowered blood glucose

High protein levels Mood disorder, anti-

psychotic, and local anesthetic med’s

Drug abuse—cocaine

Alcohol withdrawal Withdrawal from

sedative-hypnotics

TYPES OF SEIZURES Partial seizures

SimpleComplex

Generalized seizuresAbsence (petit mal)Atonic seizure (drop

attacks)Myoclonic seizureTonic-clonic (grand

mal)

STATUS EPILEPTICUS Status epilepticus is

a medical emergency brought on by repeated generalized seizures and convulsions.

Muscle spasms may block the airway, depriving the brain of oxygen.

SEIZURE MANAGEMENT Effective seizure

management involves strict adherence to drug therapy.

Choice of drug depends on the type of seizures, medical history, diagnostic studies, and the pathological processes causing the seizures.

SEIZURE MANAGEMENT Because seizures are likely to occur with abrupt withdrawal, antiseizure medications is withdrawn over a period of 6 to 12 weeks. In most cases, a single drug effectively manages seizures. Once seizures are controlled, patients are continued indefinitely on the antiseizure drug

SEIZURE MANAGEMENT Withdrawal should

only be attempted after at least 3 years of being seizure free, and only under the close observation and direction of the healthcare team.

SEIZURE MANAGEMENT Goal of antiseizure

drug therapy is to suppress neuronal activity just enough to prevent abnormal or repetitive firing.

DRUGS WITH GABA ACTION Drugs with GABA

action are drugs with the ability to mimic effects of the inhibitory neurotransmitter GABA.

Ex. Benzodiazepines, barbiturates, and miscellaneous drugs

DP-phenobarbital (luminal) pg. 182.

PHENYTOIN AND PHEYTOIN-LIKE DRUGS (HYDANTOINS) Delay influx of sodium ions

across neuronal membrane.

Ex.—hydantoins, carbamazepine (Tegretol), divalproex (Depakote), valoproic acid (Depakene)

DP for phenytoin—Dilantin pg. 185

DP for valoproic acid (Depakene) pg. 185

SUCCINIMIDES Succinimides delay

entry of calcium ions into neuron—increases electrical threshold; no impulse transmitted

DP—ethosuximide (Zarontin) pg. 186.

SOME CONTROLLED BY A PREFERRED GROUP OF DRUGS Drugs do not cure

epilepsy; just reduce number of seizures.

Same seizures do not respond to same drug.