# 73 - Depot antipsychotics  summary of pharmacokine

# Depot antipsychotics – summary of pharmacokinetics

Schizophrenia and related psychoses
CHAPTER 1
Depot antipsychotics – summary of pharmacokinetics
Table 1.9 provides a summary of the pharmacokinetics of depot antipsychotic medications.
Table 1.9  Depot antipsychotics – summary of pharmacokinetics.
Drug
UK trade name
Time to peak (days)*
Plasma half-­life 
(days)
Time to steady 
state (weeks or 
months)**
Aripiprazole1–3
Abilify Maintena
Deltoid: 4
~20 weeks
Gluteal: 5–7
Aripiprazole 2-­monthly 
injection3–6
Abilify Maintena
~29
~6 months
Aripiprazole lauroxil2
Aristada in USA
44–50
~54–57
~4 months
Aripiprazole lauroxil 
nanocrystal2,7†
Aristada Initio in 
USA
~15–18
Flupentixol decanoate8,9
Depixol
4–7
8–17
~8–12 weeks
Fluphenazine decanoate2,10–12
Modecate
8–12d††
7–10
~8 weeks
Haloperidol decanoate2
Haldol
3–9
~14 weeks
Olanzapine pamoate2,13
ZypAdhera
2–6
~12 weeks
Paliperidone palmitate2
(monthly)
Xeplion
25–49
~20 weeks
Paliperidone palmitate14,15
(3-­monthly)
Trevicta
Deltoid: 84–95
~52 weeks
Gluteal: 118–139
Paliperidone palmitate
(6-­monthly)16
Byannli
700mg: 29
700mg: 148
Not known
1000mg: 32
1000mg: 159
Pipotiazine palmitate17,18
Piportil
7–14
~9 weeks
RBP-­70002,19
(risperidone SC monthly)
Perseris in USA
1st peak ~1
~8–9
~8 weeks
2nd peak ~11
Risperidone extended-­release 
injectable suspension20,21
Rykindo in USA
25mg: 14
50mg: 17
3–6
~4 weeks
Risperidone in situ 
microimplants (ISM)22,23
Okedi
1st peak: 1–2
7–9
~4 weeks
2nd peak: 18–25
Risperidone microspheres2
Risperidal Consta
~28
3–6
~8 weeks
TV-­4600024
(risperidone SC)
Uzedy in USA
8–14
14–22
~2 months
Zuclopenthixol 
decanoate2,8,17,25
Clopixol
4–7
~12 weeks
* Time to peak is not the same as time to reach therapeutic plasma concentration but both are dependent on dose. 
For large (loading) doses, therapeutic activity is often seen before attaining peak levels. For low (test) doses, the 
initial peak level may be sub­therapeutic.
** Attainment of steady state (SS) follows logarithmic, not linear characteristics: nearly 90% of SS levels are achieved in 
three half-­lives. Time to attain steady state is independent of dose and dosing frequency (i.e. you cannot hurry it up by 
giving more, more often). Loading doses can be used to produce prompt therapeutic plasma levels but time to SS 
remains the same. SS is not the same as the concentration required for therapeutic effect. For most depots, SS 
concentrations during the dosing interval are some way above the concentration needed to give a therapeutic response.
† Used to initiate treatment with Aristada, IM injection with one 30mg oral dose of aripiprazole; not designed for 
repeat dosing.
†† Some estimates suggest peak concentrations after only a few hours.25,26 It is likely that fluphenazine decanoate 
produces two ­peaks – one on the day of injection and a second slightly higher peak a week or so later.