Chapter 18 Flashcards Preview

NURS 1065 - Pharmacology > Chapter 18 > Flashcards

Flashcards in Chapter 18 Deck (42):
1

The following are symptoms of which disorder/disease: loss of consciousness with muscle twitching and mild alterations in consciousness with repetitive blinking?

Seizures

2

True or False:
Epilepsy is a brain disorder

True

3

True or False:
Patients with patterns of seizures who are diagnosed with epilepsy are treated with anti-epileptic drugs

True

4

What are the three main ways that anti-epileptic drugs work?

1. Decreasing the rate at which sodium flows into the cell
2. Inhibiting calcium flow rate into the cell through specific channels
3. Increasing the effect of the neuroinhibitor gamma-aminobutyric acid (GABA)

5

Action potentials within neurons are initiated by an influx of what into the cell?

Sodium

6

When a cell fires, what is released into the synaptic cleft?

Neurotransmitters

7

What is the resulting action of GABA (gamma-aminobutyric acid) to glutamate?

Acts as a counterbalance
- preventing hyperexcitation

8

What is a focus?

When a group of neurons exhibits coordinated, high-frequency discharge

9

What are the causes of a focus?

- Head trauma
- Tumor growth
- Hypoxia
- Inherited birth defects

10

When does a seizure result (in regards to a focus)?

When the activity from a focus spreads to other areas of the brain
- causing other neurons to join in the hyperactivity

11

True or False:
Seizures may result from either low levels of glutamate or high levels of GABA

False
- either HIGH levels of glutamate or LOW levels of GAMA

12

When do partial seizures occur?

When focus activity is limited to an area of the brain
- within one hemisphere

13

What happens when the focus activity is within both hemispheres of the brain?

Generalized seizure symptoms occur

14

How do anti-epileptic drugs control seizures?

By decreasing sodium influx into the cells OR decreasing calcium influx into the cells

15

What is the prototype drug for anti-epileptic drugs that decreases sodium influx?

Phenytoin (Dilantin)

16

What does Phenytoin do?

Used to control partial and generalized seizures

17

What is the primary site of action of Phenytoin?

Motor cortex

18

Explain the pharmacodynamics of Phenytoin

Reversibly binds to sodium channels while they are in the inactive state

19

What are the contraindications for Phenytoin (2)?

- Bradycardia
- Heart block (abnormal heart rate - signals are blocked)

20

What are the adverse effects of Phenytoin?

- Nystagmus
- Ataxia
- Dysarthria
- Slurred speech
- Mental confusion
- Tremor
- Gingival hyperplasia

21

True or False:
Phenytoin has a broad therapeutic range

False
- it has a narrow therapeutic range

22

In order to minimize adverse effects with Phenytoin, how quickly should you administer the drug via IV push?

No faster than 50 mg/min in adults
(1-3 mg/kg/min in neonates)

23

What condition places the patient at greater risk for toxicity to Phenytoin?

Malnutrition
- causes greater amount of free, active drug in the blood b/c less protein albumin is available for binding

24

What happens in simple partial seizures?

Maybe some muscle twitching in a particular muscle group
- no loss of consciousness

25

What happens in complex partial seizures?

Involuntary muscle twitching/movement
- patient seems confused or exhibits odd behaviour

26

What are the 6 types of generalized seizures?

1. Tonic-clonic
2. Atonic
3. Status epilepticus
4. Absence
5. Myoclonic
6. Febrile

27

What happens in tonic-clonic seizures?

Entire cerebral cortex is altered by hyperexcited neurons
- tonic phase = rigidity
- clonic phase = convulsions

28

What happens in an absence seizure?

Very brief loss of consciousness
- less than 1 minute

29

What happens in atonic seizures?

Sudden loss of muscle tone
- "head drop"

30

What happens in myoclonic seizures?

Sudden rapid muscle contractions

31

What happens in status epilepticus?

One seizure follows another WITHOUT recovery of consciousness

32

What are the most common causes of status epilepticus (2)?

1. Stopping anti-epileptic drugs
2. Alcohol withdrawal

33

True or False:
The longer the status epilepticus, the higher the mortality rate

True

34

What is the therapeutic blood level of Phenytoin?

Between 10 and 20 mcg/mL

35

What should you do in order to minimize the adverse effects of Phenytoin?

Monitor blood drug levels
- important to adjust the dose to the clinical response, not the serum level

36

What is the prototype anti-epileptic drug that decreases calcium influx?

Ethosuximide (Zarontin)

37

What is Ethosuximide used to treat?

Absence (petit mal) seizures

38

Explain the pharmacodynamics of Ethosuximide

Inhibits the influx of calcium ions

39

What are the adverse effects of Ethosuximide?

- Drowsiness
- Dizziness
- Lethargy
- Nausea
- Blood dyscrasias

40

In order to minimize adverse effects of Ethosuximide, what should you assess (3)?

CBC
UA
LFT

41

True or False:
If you are discontinuing Ethosuximide, you should taper the dose gradually

True

42

If a patient is taking Ethosuximide and has an upset stomach from it, what can they take with it next time in order to prevent that?

Take the drug with milk or food if GI upset occurs