I am 100% sure it is still in my system and i dont understand why this is possible.
...because it isn't possible. You are confusing subjective feelings with objective laboratory analytics! It's
highly unlikely that after a single (!) dose 10 weeks ago any fraction of the drug is left in your system. Even without
any metabolzation (...purely fictional case), the drug would be extrected unchanged to some extend via the urine (1% ) and feces (18% ).
Aripiprazole is metabolized primarily by dehydrogenation, hydroxylation (CYP3A4 & CYP2D6) and N-dealkylation (CYP3A4). Aripiprazole is the predominant drug moiety in the systemic circulation. At steady state, dehydro-aripiprazole, the active metabolite, represents about 40% of aripiprazole AUC in plasma. Approximately 8% of Caucasians lack the capacity to metabolize CYP2D6 substrates and are classified as poor metabolizers (PM), whereas the rest are extensive metabolizers (EM). PMs have about an 80% increase in aripiprazole exposure and about a 30% decrease in exposure to the active metabolite compared to EMs, resulting in about a 60% higher exposure to the total active moieties from a given dose of aripiprazole compared to EMs. Coadministration of abilify with known inhibitors of CYP2D6 (eg. quinidine) in EMs, results in a 112% increase in aripiprazole plasma exposure, and dosing adjustment is needed. The mean elimination half-lives are about 75 hours and 146 hours for aripiprazole in EMs and PMs, respectively. Aripiprazole does not inhibit or induce the CYP2D6 pathway.
The following could be interesting for you:
"Evaluation of subjective effects of aripiprazole and methamphetamine in methamphetamine-dependent volunteers."
International Journal of Neuropsychopharmacology (2008 ), 11(8 ): 1037-1045:
Abstract
A variety of neuropharmacol. strategies are being pursued in the search for an effective treatment for methamphetamine (Meth) addiction. In this study, we investigated the safety and potential efficacy of aripiprazole, an antipsychotic agent acting on both dopamine and serotonin systems. We conducted a double-blind in-patient clin. pharmacol. study to assess potential interactions between i.v. Meth (15 mg and 30 mg) and oral aripiprazole (15 mg). In addn., the effects of aripiprazole treatment on abstinence-related craving and cue-induced craving were evaluated. Participants included non-treatment-seeking, Meth-dependent patients (n=16), aged 18-45 yr, currently using Meth. Following baseline Meth dosing (15 mg and 30 mg), participants received 2 wk treatment with aripiprazole (n=8 ) or placebo (n=8 ). Participants then completed cue exposure sessions using neutral and Meth-related cues. Meth dosing (15 mg and 30 mg) was then repeated. Aripiprazole treatment had no effect on cue-induced Meth craving, or on daily baseline craving assessed over the course of medication treatment, although aripiprazole treatment was assocd. with increased craving independent of Meth dosing. Aripiprazole treatment was assocd. with significantly higher ratings on Addiction Research Center Inventory (ARCI) subscales reflecting euphoria and amphetamine-like effects following Meth dosing. Aripiprazole treatment was also assocd. with significant redns. in ratings of bad effects' and redns. on the ARCI subscale for sedation effects following Meth dosing. Aripiprazole treatment reduced the increase in systolic blood pressure following Meth dosing, but had no other effects on cardiovascular responses to Meth. Aripiprazole treatment did not alter the pharmacokinetics of Meth.
These findings indicate that aripiprazole treatment appears to be safe in volunteers with Meth dependence, although the finding that aripiprazole increased some of the rewarding and stimulatory effects produced by acute Meth suggests that 15 mg aripiprazole is unlikely to be efficacious for the treatment of Meth dependence. Further research with lower doses of aripiprazole, possibly using study designs aimed at evaluating efficacy for relapse prevention, are needed before ruling out aripiprazole as a treatment for Meth dependence.
"Pharmacokinetics of domestic aripiprazole after single and multiple dosing in healthy volunteers."
Zhongguo Yaoxue Zazhi (Beijing, China) (2007), 42(24): 1892-1895
Abstract
A HPLC-UV method was developed for determing aripiprazole in human plasma, and the pharmacokinetic profiles of domestic Aripiprazole tablets in healthy volunteers were studied. A single and multiple oral doses of domestic aripiprazole were given to 12 and 14 healthy volunteers resp. Aripiprazole concentrations in plasma were determined by HPLC method. The pharmacokinetic parameters of aripiprazole were obtained with statistical analysis by DAS1.0.
The main pharmacokinetic parameters of a single dose of aripiprazole were as followed: ρmax was (108.4 22.5) µg/L-1, tmax was (4.9 0.7) h, AUC0-192h was (5748.2 874.5) µg/h/L-1, t1/2β was (107.4 29.0) h, CL/F was (3.56 0.55) L/h-1 and V/F was (261.6 49.1) L.
In multiple dose study, aripiprazole were given to the healthy volunteers for 14 d to achieve steady state, the peak concentrations of (480.3 126.2) µg/L-1 and was reached at (4.0 0.9) h after the last administration in steady state. AUC0-360h was (38166.6 13241.2) µg/h/L-1, t1/2β was (91.0 21.1) h, CL/F was (0.62 0.36) L/h-1 and V/F was (60.9 43.7) L. The concentration-time curves of aripiprazole were described by a two-compartment open model. And it offered necessary information for clinical use of aripiprazole in Chinese.
Note: This data is comparable to data obtained in caucasian patients.
"Pharmacokinetics of aripiprazole, a new antipsychotic, following oral dosing in healthy adult Japanese volunteers: influence of CYP2D6 polymorphism."
Drug Metabolism and Pharmacokinetics (2007), 22(5): 358-366
Abstract
We investigated the pharmacokinetics (PK) of aripiprazole, a newly developed antipsychotic, and its active metabolite in healthy Japanese, and the influence of CYP2D6 polymorphism on the PK of aripiprazole. Following a single oral 6 mg dose, the mean Cmax, tmax, and t1/2,z (terminal phase half life) of aripiprazole were 31.0 ng/mL, 3.6 h, and 61.0 h, resp. The t1/2,z in CYP2D6 IM subjects (75.2 h) was significantly (p < 0.01) longer than that in CYP2D6 EM subjects (45.8 h), and the systemic clearance of IM subjects was approx. 60% that of EM subjects. The PK in one subject with the CYP2D6*41 homozygote was similar to that of IM subjects. In repeated oral administration, plasma concns. of aripiprazole and active metabolite both reached a steady state by Day 14. The half-life of aripiprazole following repeated administration was similar to that following single administration, suggesting that pharmacokinetics was const. during 14-day administration. Our investigations revealed that there is no clear ethnic difference between Japanese and Western subjects in terms of mean plasma PK, while the CYP2D6*10 allele distinctive to Asian populations influences the PK of aripiprazole. Moreover, our observations suggest that the CYP2D6*41 allele significantly affects drug-metabolizing activity.
Note: IM = intermediate metabolizer, EM = extensive metabolizer
Further detailed information here:
http://www.druglib.com/druginfo/abilify/description_pharmacology/
