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NRNP 6675 FINAL EXAM LAST EXAM QUESTION AND DETAILED
CORRECT ANSWERS 2023
1. The 1/2 life of lithium is about?: 24 hours
2. Fluoxetine is the SSRI with the WD risk?: lowest due to long half life
3. What antipsychotics are good for pts who miss doses of their meds?: An-
tipsychotics with long half-lives:
1. Cariprazine(Vrylar): (2-4 days-active metabolites up to 3 weeks)
- Abilify (3 days)
- Brexipiprazole (4 days)
- Pimozide (4-5 days)
- Pimavanserin (2 days, active metabolites 8 days)
- Disulfiram's alcohol interactions persist for up to how long after the med-
ication is stopped?: LONG Half life--2-3 days
persist up to 2 weeks following stopping
5. What is the only TCA with a long half life?: Protriptyline (Vivactil)
6. Most psychotropics have a medium range 1/2 life of approx?: 24 hours
- what does "steady state" mean in relation to 1/2 life?: steady state means that
- Lithium reaches its 'steady state' when?: 5 half lives 1 / 3
you are eliminating the drug at the same overall rate that you are ingesting it
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example:
Day 1: Start pt on Lithium 600 mg daily
Day 2: (24 hours later) the amount left in his body is 300 mg (day 2 min) because 24 hours has passed--one 1/2 life--therefore the pt has excreted 1/2 of the initial amount.THEN the pt takes his 2nd dose of 600 mg on DAY 2-resulting in a max dose of 900 (300 mg left in body + 600 mg of 2nd dose).DAY 3: starts off with 450 mg (1/2 of the 900 mg in pt's system) and after taking the day 3 600 mg dose, the pt now has a total of 1050 mg.
9. Due to the steady state of Lithium, when do we draw a blood level?: 5 half
lives if you check any earlier, the trough level will underestimate the actual level the pt is on after achieving steady state
10. Fluoxetine has a half life of about?: 2 weeks 1/2 life
take 2.5 months to achieve steady state
- Most psychotropic medications operate in this fashion:: "when you double
the dose, the serum dose doubles." 2 / 3
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*minus three SRIs and three anticonvulsants (Fluoxetine, fluvoxamine, paxil, gabapentin, valproate and carbamazepine)
- induces it's own metabolism, hastening excretion and shorten-
ing it's half life: A. Carbamazepine (Tegretol)
*this effect begins to "rev up" after 2-4 weeks--which is why a carbamazepine level is so important on obtaining 1-2 months after starting Tegretol.
- Carbamazepine (Tegretol) level should be checked how soon after starting
to take this med?: 1-2 months due to Tegretol inducing it's own metabolism,
hastening excretion and shortening it's half life.
- has trouble getting a "serum" level because it binds to proteins that
render it therapeutically inactive?: A. Valproate Acid (Depakote)
-this is particularly true at the lower levels (eg. <50 mcg/mL), so you can expect dose changes to make a more dramatic difference when the pt's depakote level is in the higher range
15. 's serum level is the opposite of Valproic Acid: it rises quickly at
first and then slows down?: Gabapentin
*gabapentin saturates the transporters that absorb it in the small intestine, causing its levels to rise at a snails pace when the dosage goes above a certain saturation point (around 900 mg/day).-from there, the saturation trickles down; @ 900 mg/day--60% is absorbed. @ 1200
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