7.10 Drugs Metabolized by CYP2C9
 
Results of in vitro studies demonstrate that duloxetine does not inhibit activity. In a clinical study, the pharmacokinetics of S-warfarin, a CYP2C9 substrate, were not significantly affected by duloxetine [see Drug Interactions (7.4)].

7.11 Drugs Metabolized by CYP3A
 
Results of in vitro studies demonstrate that duloxetine does not inhibit or induce CYP3A activity. Therefore, an increase or decrease in the metabolism of CYP3A substrates (e.g., oral contraceptives and other steroidal agents) resulting from induction or inhibition is not anticipated, although clinical studies have not been performed.

7.12 Drugs Metabolized by CYP2C19
 
Results of in vitro studies demonstrate that duloxetine does not inhibit CYP2C19 activity at therapeutic concentrations. Inhibition of the metabolism of CYP2C19 substrates is therefore not anticipated, although clinical studies have not been performed.

7.13 Monoamine Oxidase Inhibitors (MAOIs)
 
[see Dosage and Administration (2.8, 2.9), Contraindications (4), and Warnings and Precautions (5.4)].

7.14 Serotonergic Drugs
 
[see Dosage and Administration (2.8, 2.9), Contraindications (4), and Warnings and Precautions (5.4)].

7.15 Alcohol
 
When duloxetine and ethanol were administered several hours apart so that peak concentrations of each would coincide, duloxetine did not increase the impairment of mental and motor skills caused by alcohol.

In the duloxetine clinical trials database, three duloxetine-treated patients had liver injury as manifested by ALT and total bilirubin elevations, with evidence of obstruction. Substantial intercurrent ethanol use was present in each of these cases, and this may have contributed to the abnormalities seen [see Warnings and Precautions (5.2, 5.12)].

7.16 CNS Drugs
 
[see Warnings and Precautions (5.12)]. 

7.17 Drugs Highly Bound to Plasma Protein
 
Because duloxetine is highly bound to plasma protein, administration of duloxetine delayed-release capsules to a patient taking another drug that is highly protein bound may cause increased free concentrations of the other drug, potentially resulting in adverse reactions. However, co-administration of duloxetine (60 or 120 mg) with warfarin (2-9 mg), a highly protein-bound drug, did not result in significant changes in INR and in the pharmacokinetics of either total S-or total R-warfarin (protein bound plus free drug) [see Drug Interactions (7.4)].
 
8 USE IN SPECIFIC POPULATIONS

8.1 Pregnancy
 
 Pregnancy Category C 

Risk Summary — There are no adequate and well-controlled studies of duloxetine administration in pregnant women. In animal studies with duloxetine, fetal weights were decreased but there was no evidence of teratogenicity in pregnant rats and rabbits at oral doses administered during the period of organogenesis up to 4 and 7 times the maximum recommended human dose (MRHD) of 120 mg/day, respectively. When duloxetine was administered orally to pregnant rats throughout gestation and lactation, pup weights at birth and pup survival to 1 day postpartum were decreased at a dose 2 times the MRHD. At this dose, pup behaviors consistent with increased reactivity, such as increased startle response to noise and decreased habituation of loc