SzAdmin
September 21, 2015, 5:01pm
1
Important if you take Armodafinil (for sleep problems) and Risperdal. They seem to reduce the effectivness of each other.
CONCLUSION:
Consistent with CYP3A4 induction, risperidone and 9-hydroxyrisperidone systemic exposure was reduced in the presence of armodafinil.
Simultaneous armodafinil and risperidone use may necessitate risperidone dosage adjustment, particularly when starting or stopping coadministration of the two drugs. However, any such decision should be based on patient disease state and clinical status.
Source:
M Darwish, M Bond, R Yang, ET Hellriegel and P Robertson,
Clinical drug investigation , Nov 2015
Patients with bipolar I disorder and schizophrenia have an increased risk of obstructive sleep apnea. The effects of armodafinil, a weak cytochrome P450 (CYP) 3A4 inducer, on pharmacokinetics and safety of risperidone, an atypical antipsychotic used to treat major psychiatric illness, were investigated.Healthy subjects received 2 mg risperidone alone and after armodafinil pretreatment (titrated to 250 mg/day). Pharmacokinetic parameters were derived from plasma concentrations of risperidone and its active metabolite, 9-hydroxyrisperidone (formed via CYP2D6 and CYP3A4), collected before and over 4 days after risperidone administration, and from steady-state plasma concentrations of armodafinil and its circulating metabolites, R-modafinil acid and modafinil sulfone. Safety and tolerability were assessed.Thirty-six subjects receiving study drug were evaluable for safety; 34 were evaluable for pharmacokinetics. Risperidone maximum plasma concentration (C max) decreased from mean 16.5 ng/mL when given alone to 9.2 ng/mL after armodafinil pretreatment (geometric mean ratio [90 % CI] 0.55 [0.50-0.61]); area under the plasma concentration-time curve from time 0 to infinity (AUC0-∞) decreased from 92.3 to 44.5 ng·h/mL (geometric mean ratio [90 % CI] 0.51 [0.46-0.55]). C max and AUC0-∞ for 9-hydroxyrisperidone were also reduced (geometric mean ratios [90 % CI] 0.81 [0.77-0.85] and 0.73 [0.69-0.77], respectively). Adverse events were consistent with known safety profiles.Consistent with CYP3A4 induction, risperidone and 9-hydroxyrisperidone systemic exposure was reduced in the presence of armodafinil. Concomitant armodafinil and risperidone use may necessitate risperidone dosage adjustment, particularly when starting or stopping coadministration of the two drugs. However, any such decision should be based on patient disease state and clinical status.
2 Likes
I wonder if this applies to Modafinil as well.
SzAdmin
September 21, 2015, 6:07pm
3
SzAdmin:
Armodafinil
I think YES - they are the same thing it seems:
Armodafinil (trade name Nuvigil) is the enantiopure compound of the eugeroic modafinil (Provigil). It consists of only the (R)-(−)-enantiomer of the racemic modafinil. Armodafinil is produced by the pharmaceutical company Cephalon Inc. and was approved by the U.S. Food and Drug Administration (FDA) in June 2007. In 2016, the FDA granted Mylan rights for the first generic version of Cephalon's Nuvigil to be marketed in the U.S.
Because armodafinil has a longer half-life than modafinil does, it m...
Something to remember if I ever go back on Risperidone.
1 Like
Jayster
September 22, 2015, 12:51am
5
I feel like being a letter of the law guy . Nuvigil is the prefferred isomer of Provigil. Technically modafinil and Nuvigil are not the same. But for the puposes at hand . . .
Jayster
