Antipsychotics-pharmacokinetics Flashcards
1
Q
Typical antipsychotics
A
Haldol (haloperidol) Loxitane (loxapine) Mellaril (thioridazine) Moban (molindone) Navane (thiothixene) Prolixin (fluphenazine) Serentil (mesoridazine) Stelazine (trifluoperazine) -usually CYP1A or CYP2D6 substrates and can inhibit 2D6
2
Q
Typical antipsychotics half lives
A
10-30 hrs
3
Q
Enzyme inducers
A
-carbamazepine
-phenytoin
-ethambutol
barbiturates
=all reduce antipsychotic levels
4
Q
Clearance inhibitors
A
- SSRIs, TCAs, cimetidine, erythromycin, ciprofloxacin and keotconazole
- inhibit metabolism
- increase antipsychotic levels
5
Q
Flupenthixol IM
A
- esterified in coconut oil
- peak levels 3-7 days post IM
- half life of 17 days
6
Q
Fluphenazine IM
A
- esterified in sesame oil
- peak levels are 24 hrs post-IM
- apparent half-life of 7-14 days
- smoking reduces levels
7
Q
Haloperidol IM
A
- esterified in sesame oil
- peak levels 7 days post-IM
- apparent half-life of 3 weeks
- smoking reduces levels through induced CYP
8
Q
Perphenazine decanoate IM
A
- esterified in sesame oil
- peak level 1-7 days post IM
- half life 2 weeks
9
Q
Pipotiazine
A
- peak levels 1-2 weeks post IM
- half life 2 weeks
10
Q
Zuclopenthixol decanoate
A
peak level 1 week post IM
-half life 7-20 days
11
Q
Risperidone
A
- extensive first past metabolism to 9-hydroxyrisperiodne, an active metabolite
- CYP2D6 catalyzes hydroxylation or riseridone
- 90% protein boud, metabolite in 77%
- half life 15 hours
12
Q
Paliperidone
A
- major active metabolite of risperidone (9-OH)
- potent 5Ht2 blocker and partially blocks D2 receptors
- efficacy and side effects are same as risperidone
13
Q
Quetiapine
A
- short half life of 6-12 hours
- multiple daily dosing required
14
Q
Aripiprazole
A
- 90hr half life!
- steady state concentrations are achieved at 14 days
- metabolised by CYP3A4 and CYP2D6
- 99% protein bound
