Correct Answers Graded A+
The 1/2 life of lithium is about? - Answer: 24 hours
Fluoxetine is the SSRI with the ______ WD risk? - Answer: lowest due to long half life
What antipsychotics are good for pts who miss doses of their meds? - Answer: Antipsychotics with long
half-lives:
1. Cariprazine(Vrylar): (2-4 days-active metabolites up to 3 weeks)
2. Abilify (3 days)
3. Brexipiprazole (4 days)
4. Pimozide (4-5 days)
5. Pimavanserin (2 days, active metabolites 8 days)
Disulfiram's alcohol interactions persist for up to how long after the medication is stopped? - Answer:
LONG Half life--2-3 days
persist up to 2 weeks following stopping
What is the only TCA with a long half life? - Answer: Protriptyline (Vivactil)
Most psychotropics have a medium range 1/2 life of approx? - Answer: 24 hours
what does "steady state" mean in relation to 1/2 life? - Answer: steady state means that you are
eliminating the drug at the same overall rate that you are ingesting it
Lithium reaches its 'steady state' when? - Answer: 5 half lives
,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.
Due to the steady state of Lithium, when do we draw a blood level? - Answer: 5 half lives
if you check any earlier, the trough level will underestimate the actual level the pt is on after achieving
steady state
Fluoxetine has a half life of about? - Answer: 2 weeks 1/2 life
take 2.5 months to achieve steady state
Most psychotropic medications operate in this fashion: - Answer: "when you double the dose, the serum
dose doubles."
*minus three SRIs and three anticonvulsants (Fluoxetine, fluvoxamine, paxil, gabapentin, valproate and
carbamazepine)
_________induces it's own metabolism, hastening excretion and shortening it's half life - Answer: 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? - Answer:
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? - Answer: 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
_______'s serum level is the opposite of Valproic Acid: it rises quickly at first and then slows down? -
Answer: 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 mg/day--50 % is
absorbed. @3000 mg/day--30% of the gabapentin is absorbed.
Due to Gabapentin's serum pattern for dosage:
@ 900 mg/day, how much is the patient absorbing? - Answer: @ 0900mg/day---60% is absorbed.
Due to Gabapentin's serum pattern for dosage:
@ 1200 mg/day, how much is the patient absorbing? - Answer: @ 1200 mg/day--50 % is absorbed.
Due to Gabapentin's serum pattern for dosage:
@ 3000 mg/day, how much is the patient absorbing? - Answer: @3000 mg/day--30% of the gabapentin
is absorbed.
Carbamazepine (Tegretol's) serum level drops after how long after stopping taking it? - Answer: 1-2
months