Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Phar 770 > Phenytoin (Concepts) > Flashcards

Phenytoin (Concepts) Flashcards

1
Q

Uses of Phenytoin

A

Generalized tonic-clonic seizures

Complex partial seizures

Prevention following neurosurgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Phenytoin MOA

A

Increases efflux or decreases influx of Na.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

S of Phenytoin acid

A

1.0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

S of Phenytoin sodium

A

0.92

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Oral Phenytoin

A

Dilantin Kapseals = Phenytoin Sodium capsules

Generic Phenytoin sodium capsules as well

Dilantin-125 suspension
- per 5mL

Dilantin Infatabs = Phenytoin acid chewable tablets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Can you substitute rapid and sustained-release phenytoin products?

A

No.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Phenytoin administration considerations

A

Be consistent in terms of with or without meals.

Pause continuous nasogastric feeding for 1-2 hours before and after dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Brand-Generic considerations

A

Don’t switch if no reason.

Contact prescriber before making change.

Maintain generic supplier.

Careful consideration with:

  • elderly
  • patients requiring levels of 20mg/L or more.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Phenytoin IV products

A

Dilantin IV

Fosphenytoin (Cerebyx)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Dilantin IV characteristics

A
  • Phenytoin sodium!
  • S = 0.92, even though IV
  • 30 min infusion
  • Monitoring required.
  • ONLY NS; 100-150mL
  • Infuse within 4 hours of mixing.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Fosphenytoin characteristics

A

Prodrug: converted to phenytoin by plasma esterases.

  • More water soluble.
  • Dose expressed in Phenytoin SODIUM equivalents (PE)
  • Dilute to [1.5-25]
  • 30 min infusion
  • Requires monitoring
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which IV phenytoin product is preferred in Peds?

A

Fosphenytoin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which IV phenytoin can be given IM?

A

Fosphenytoin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which IV phenytoin can be put in NS or D5W?

A

Fosphenytoin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which IV phenytoin needs an in-line filter?

A

Phenytoin sodium (Dilantin IV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which IV phenytoin contains propylene glycol?

A

Phenytoin sodium (Dilantin IV)

17
Q

Weight based dosing of Fosphenytoin:

A

15-20mg PE/kg in adults

10-20mg PE/kg in peds

18
Q

IV phenytoin max rate

A

50mg/min

19
Q

IV fosphenytoin max rate

A

150mgPE/min

20
Q

IV phenytoin : IV fosphenytoin conversion

A

1mg phenytoin sodium

1.5mg fosphenytoin

21
Q

Adverse Events seen with Parenteral Products DURING INFUSION

A

Can be severe:

  • Hypotension
  • Bradycardia
  • Dysrhythmias
  • Lethargy
22
Q

Adverse Events seen with Parenteral Products depending on SERUM LEVELS

A

15mg/mL
- drowsy/fatigue

20mg/mL
- nystagmus

30mg/mL
- ataxia, incoordination

40mg/mL
- mental status changes (even coma)

Over 50-60
- drug-induced seizures

23
Q

Adverse Effects seen with Parenteral Products after LONG TERM use

A

Hypertrichosis*
Gingival hyperplasia*

Altered facial features
Carbohydrate intolerance/hyperglycemia
Folate deficiency
VitD deficiency
SLE (drug-induced lupus)
24
Q

Purple Glove Syndrome

A

Seen with multiple large doses of IV phenytoin:

DC it.

25
Q

Monitoring during IV infusion

A

Cardiac monitor/telemetry

Someone actually there

26
Q

Therapeutic Ranges

A

Total

  • Children/Adults: 10-20
  • Neonates: 8-15

Free
- 1-2.5 (more important)

27
Q

3 Reasons to draw free levels

A

Concern subtherapeutic

Concern toxicity

Renal-failure

28
Q

Causes of hypoalbuminemia that alter phenytoin plasma protein binding?

A

Liver disease: dec. synthesis

Nephrotic syndrom: urine-losses

Burns: hypermetabolic

Trauma: hypermetabolic

Malnourishment

Eldery

29
Q

Causes of displacement from plasma proteins due to ENDOGENOUS compounds

A

Hyperbilirubinemia
- Jaundice/liver disease

Toxin accumulation
- Renal dysfunction

30
Q

Causes of displacement from plasma proteins due to EXOGENOUS compunds

A

Warfarin
Valproic acid
Aspirin > 2g….
NSAIDs

31
Q

Phenytoin: low E or high E?

A

Low E.

32
Q

Css,total with increased Fup

A

Decreased

33
Q

Css,free with increased Fup

A

Decreased

34
Q

Michaellis-Menten PK

A

Used b/c enzyme system responsible for extraction/metabolism is saturable.

Phar 770 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions