DUEXIS Coated tablet Ref.[50734] Active ingredients: Famotidine Ibuprofen

In a healthy volunteer study, ibuprofen 400 mg given once daily, administered 2 hours prior to immediate-release aspirin (81 mg) for 6 days, showed an interaction with the antiplatelet activity of aspirin as measured by % serum thromboxane B2 (TxB2) inhibition at 24 hours following the day-6 aspirin dose [53%]. An interaction was still observed, but minimized, when ibuprofen 400 mg given once-daily was administered as early as 8 hours prior to the immediate-release aspirin dose [90.7%]. However, there was no interaction with the antiplatelet activity of aspirin when ibuprofen 400 mg, given once daily, was administered 2 hours after (but not concomitantly, 15 min, or 30 min after) the immediate-release aspirin dose [99.2%].

In another study, where immediate-release aspirin 81 mg was administered once daily with ibuprofen 400 mg given three times daily (1, 7, and 13 hours post-aspirin dose) for 10 consecutive days, the mean % serum thromboxane B2 (TxB2) inhibition suggested no interaction with the antiplatelet activity of aspirin [98.3%]. However, there were individual subjects with serum TxB2 inhibition below 95%, with the lowest being 90.2%.

When a similarly designed study was conducted with enteric-coated aspirin, where healthy subjects were administered enteric-coated aspirin 81 mg once daily for 6 days and ibuprofen 400 mg three times daily (2, 7, and 12 h post-aspirin dose) for 6 days, there was an interaction with the antiplatelet activity at 24 hours following the day-6 aspirin dose [67%] [see Drug Interactions (7)].

Absorption

Ibuprofen and famotidine are rapidly absorbed after a single dose administration of DUEXIS. Mean C_max values for ibuprofen are 45 µg/mL and are reached approximately 1.9 hours after oral administration of DUEXIS. The C_max and AUC_0-24hours values for the 800 mg of ibuprofen contained in a DUEXIS tablet are bioequivalent to the values for 800 mg of ibuprofen administered alone. C_max values for famotidine were 61 ng/mL and are reached at approximately 2 hours after oral administration of DUEXIS.

A high-fat meal reduced famotidine C_max and AUC by approximately by 15% and 11%, respectively, and reduced ibuprofen AUC by approximately 14% but did not change C_max. Food delayed famotidine T_max and ibuprofen T_max by approximately 1 hour and 0.2 hour, respectively.

Distribution

Ibuprofen is extensively bound to plasma proteins.

Fifteen to 20% of famotidine in plasma is protein bound.

Elimination

Metabolism

The only metabolite of famotidine identified in man is the S-oxide.

Excretion

Ibuprofen is eliminated from the systemic circulation with a mean half-life (t_1/2) value of 2 hours following administration of a single dose of DUEXIS.

Ibuprofen is rapidly metabolized and eliminated in the urine. The excretion of ibuprofen is virtually complete 24 hours after the last dose.

Studies have shown that following ingestion of the drug, 45% to 79% of the dose was recovered in the urine within 24 hours as metabolite A (25%), ()2[p-(2-hydroxymethyl-propyl) phenyl] propionic acid and metabolite B (37%), ()- 2-[p-(2-carboxypropyl)phenyl] propionic acid; the percentages of free and conjugated ibuprofen were approximately 1% and 14%, respectively.

Famotidine is eliminated from the systemic circulation with a mean t_1/2 value of 4 hours following administration of a single dose of DUEXIS.

Famotidine is eliminated by renal (65-70%) and metabolic (30-35%) routes. Renal clearance is 250-450 mL/min, indicating some tubular excretion. Twenty-five to 30% of an oral dose and 65-70% of an intravenous dose are recovered in the urine as unchanged compound.

1Specific Populations

Pediatrics

The pharmacokinetics of ibuprofen or famotidine after administration of DUEXIS have not been evaluated in a pediatric population considering the doses of ibuprofen and famotidine in DUEXIS are targeted for use in an adult population.

Hepatic impairment

The effects of hepatic impairment on the pharmacokinetics of ibuprofen or famotidine after administration of DUEXIS have not been evaluated [see Warnings and Precautions (5.4)].

Renal impairment

There is a close relationship between creatinine clearance values and the elimination t_1/2 of famotidine, which is a component of DUEXIS tablets. In patients with creatinine clearance <50 mL/min, the elimination t_1/2 of famotidine is increased and may exceed 20 hours. Therefore, DUEXIS is not recommended in patients with creatinine clearance <50 mL/min [see Warnings and Precautions (5.7)].

Drug Interaction Studies

Co-administration of ibuprofen (800 mg) and famotidine (40 mg) increased ibuprofen C_max by 15.6% but did not affect its AUC, and increased famotidine AUC and C_max by 16% and 22%, respectively.

Aspirin

When NSAIDs were administered with aspirin, the protein binding of NSAIDs were reduced, although the clearance of free NSAID was not altered. The clinical significance of this interaction is not known. See Table 3 for clinically significant drug interactions of NSAIDs with aspirin [see Drug Interaction (7)].

Probenecid, an inhibitor of Organic Aniton Transporter 1 (OAT1) and OAT3

In vitro studies indicate that famotidine is a substrate for OAT1 and OAT3. Following coadministration of probenecid (1500 mg) with a single oral 20 mg dose of famotidine in 8 healthy subjects, the serum AUC_0-10h of famotidine increased from 424 to 768 ng×hr/mL and the maximum serum concentration (C_max) increased from 73 to 113 ng/mL. Renal clearance, urinary excretion rate and amount of famotidine excreted unchanged in urine were decreased. The clinical relevance of this interaction is unknown.

Metformin

Famotidine is a selective inhibitor of multidrug and toxin extrusion transporter 1 (MATE-1) but no clinical significant interaction with metformin, a substrate for MATE-1, was observed.

Carcinogenesis

Studies to evaluate the potential effects of DUEXIS on carcinogenicity, mutagenicity, or impairment of fertility have not been conducted.

In a 106-week study in rats and a 92-week study in mice, famotidine was given at oral doses of up to 2000 mg/kg/day (approximately 122 and 243 times the recommended human dose, respectively, based on body surface area). There was no evidence of carcinogenic potential for famotidine.

Mutagenesis

Famotidine was negative in the microbial mutagen test (Ames test) using Salmonella typhimurium and Escherichia coli with or without rat liver enzyme activation at concentrations up to 10,000 µg/plate. In in vivo mouse micronucleus test and a chromosomal aberration test with famotidine, no evidence of a mutagenic effect was observed.

In published studies, ibuprofen was not mutagenic in the in vitro bacterial reverse mutation assay (Ames assay).

Impairment of Fertility

In studies of famotidine in rats at oral doses of up to 2000 mg/kg/day (approximately 243 times the recommended human dose, based on body surface area), fertility and reproductive performance were not affected.

In a published study, dietary administration of ibuprofen to male and female rats 8-weeks prior to and during mating at dose levels of 20 mg/kg (0.06-times the MRHD based on body surface area comparison) did not impact male or female fertility or litter size.

In other studies, adult mice were administered ibuprofen intraperitoneally at a dose of 5.6 mg/kg/day (0.0085-times the MRHD based on body surface area comparison) for 35 or 60 days in males and 35 days in females. There was no effect on sperm motility or viability in males but decreased ovulation was reported in females.

Two multicenter, double-blind, active-controlled, randomized, 24-week studies of DUEXIS were conducted in patients who were expected to require daily administration of an NSAID for at least the coming 6 months for conditions such as the following: osteoarthritis, rheumatoid arthritis, chronic low back pain, chronic regional pain syndrome, and chronic soft tissue pain. Patients were assigned randomly, in approximately a 2:1 ratio, to treatment with either DUEXIS or ibuprofen (800 mg) three times a day for 24 consecutive weeks. A total of 1533 patients were enrolled and ranged in age from 39 to 80 years (median age 55 years) with 68% females. Race was distributed as follows: 79% Caucasian, 18% African-American, and 3% Other. Approximately 15% of the patients in Studies 301 and 303 were taking concurrent low-dose aspirin (less than or equal to 325 mg daily), 18% were 65 years of age or older, and 6% had a history of previous upper gastrointestinal ulcer. Although H. pylori status was negative at baseline, H. pylori status was not reassessed during the trials.

Studies 301 and 303 compared the incidence of upper gastrointestinal (gastric and/or duodenal) ulcer formation in a total 930 patients taking DUEXIS (ibuprofen and famotidine) and 452 patients taking ibuprofen only, either as a primary or secondary endpoint. In both trials, DUEXIS was associated with a statistically significantly reduction in the risk of developing upper gastrointestinal ulcers compared to taking ibuprofen only during the 6 month study period. The data are presented below in Tables 4 and 5. Two analyses for each endpoint were conducted. In one analysis patients who terminated early, without an endoscopic evaluation within 14 days of their last dose of study drug, were classified as not having an ulcer. In the second analysis, those patients were classified as having an ulcer. Both analyses exclude patients who terminated study prior to the first scheduled endoscopy at 8 weeks.

Table 4. Overall Incidence Rates of Patients Who Developed at Least One Upper Gastrointestinal or Gastric Ulcer – Study 301:

^* Cochran-Mantel-Haenszel test
^† Classifying early terminated patients as NOT having an ulcer
^‡ Classifying patients who early terminated due to an adverse event, were lost to follow-up, discontinued due to the discretion of the sponsor or the investigator, or did not have an endoscopy performed within 14 days of their last dose of study drug, as having an ulcer

Table 5. Overall Incidence Rate of Patients Who Developed at Least One Gastric or Upper Gastrointestinal Ulcer – Study 303:

^* Cochran-Mantel-Haenszel test
^† Classifying early terminated patients as NOT having an ulcer
^‡ Classifying patients who early terminated due to an adverse event, were lost to follow-up, discontinued due to the discretion of the sponsor or the investigator, or did not have an endoscopy performed within 14 days of their last dose of study drug, as having an ulcer

Subgroup analyses of patients who used low-dose aspirin (less than or equal to 325 mg daily), were 65 years and older, or had a prior history of gastrointestinal ulcer are summarized as follows:

Of the 1022 patients in clinical studies of DUEXIS, 15% (213 patients) used low-dose aspirin and the results were consistent with the overall findings of the study. In these clinical studies 16% of patients who used low-dose aspirin who were treated with DUEXIS developed an upper gastrointestinal ulcer compared to 35% of those patients who received only ibuprofen.

The clinical trials primarily enrolled patients less than 65 years without a prior history of gastrointestinal ulcer. Of the 1022 patients in clinical studies of DUEXIS, 18% (249 patients) were 65 years of age or older. In these clinical studies, 23% of patients 65 years of age and older who were treated with DUEXIS developed an upper gastrointestinal ulcer compared to 27% of those patients who received only ibuprofen [see Use in Specific Populations (8.5)].

Of the 1022 patients in clinical studies of DUEXIS, 6% had a prior history of gastrointestinal ulcer. In these clinical studies, 25% of patients with a prior history of gastrointestinal ulcer who were treated with DUEXIS developed an upper gastrointestinal ulcer compared to 24% of those patients who received only ibuprofen.