Background: To evaluate potential drug-drug interactions with the atypical antipsychotic lurasidone. Methods: Seven phase I studies were conducted to investigate the effects of repeated dosing of ketoconazole, diltiazem, rifampin, or lithium on the pharmacokinetics (PK) of single oral doses of lurasidone, or the effects of repeated dosing of lurasidone on the PK of digoxin, midazolam, or the oral contraceptive norgestimate/ethinyl estradiol. Two 6-week, phase III studies included evaluation of the potential for interaction between lurasidone and lithium or valproate. Maximum serum or plasma concentration (C max ) and area under the concentration-time curve (AUC) were calculated. Results: Concomitant ketoconazole administration resulted in a 6.8-fold increase in lurasidone C max and a 9.3-fold increase in lurasidone AUC; concomitant diltiazem administration resulted in 2.1-and 2.2-fold increases, respectively. Rifampin decreased lurasidone C max and AUC (one-seventh and onefifth of lurasidone alone, respectively). Steady-state dosing with lurasidone increased C max and AUC 0-24 (AUC from time 0 to 24 h postdose) of digoxin by 9% and 13%, respectively, and of midazolam by 21% and 44%, respectively. There were no significant interactions between lurasidone and lithium, valproate, ethinyl estradiol, or norelgestromin (the major active metabolite of norgestimate). Conclusions: Lurasidone PK is altered by strong cytochrome P450 (CYP) 3A4 inhibitors or inducers, and coadministration is contraindicated; whereas moderate CYP3A4 inhibitors have less effect, and lurasidone dosage restrictions are recommended. No dose adjustment

The pharmacokinetics (PK) and pharmacodynamics (PD) of clinically relevant doses of repository corticotropin injection (Acthar Gel) and synthetic ACTH1‐24 depot have not been fully characterized. We compared the steroidogenic exposure of repository corticotropin injection and synthetic ACTH1‐24 depot in healthy adults at therapeutic doses using data from 2 separate phase 1 studies. Subjects were randomly assigned to repository corticotropin injection 40 or 80 IU subcutaneously twice weekly or 80 IU subcutaneously 3 times weekly for 15 days or to daily synthetic ACTH1‐24 depot doses of 0.5 mg subcutaneously, 0.75 mg subcutaneously, 1 mg subcutaneously, or 1 mg intramuscularly for 5 days. A population PK/PD model was developed to simulate the free cortisol exposure of a clinically relevant dose of synthetic ACTH1‐24 depot (1 mg subcutaneously twice weekly). Study drug doses were converted to methylprednisolone‐equivalent doses using the steroidogenic exposure of methylprednisolone 16 mg daily as a conversion factor. Doses were also converted to prednisone equivalents using a coefficient of 1.25. These analyses revealed that the steroidogenic exposure of repository corticotropin injection at clinically relevant doses was substantially lower than that for synthetic ACTH1‐24 depot. The 3 repository corticotropin injection regimens were equivalent to approximately 5, 8, and 16 mg of daily prednisone, respectively. On the basis of simulated free cortisol exposure, synthetic ACTH1‐24 depot 1 mg subcutaneously twice weekly was comparable to 57 mg of daily prednisone. These results suggest that repository corticotropin injection has pharmacological effects that cannot be considered identical to synthetic ACTH1‐24 depot.

Lurasidone should be administered with food-at least 350 kcal-to ensure maximum exposure.