Diclofenac Sodium and Misoprostol (diclofenac sodium 50 mg misoprostol 200 ug) Dailymed

Administration of misoprostol, a component of diclofenac sodium and misoprostol delayed-release tablets, to pregnant women can cause uterine rupture, abortion, premature birth, or birth defects. Uterine rupture has occurred when misoprostol was administered to pregnant women to induce labor or an abortion. Diclofenac sodium and misoprostol delayed-release tablets are contraindicated in pregnant women. Diclofenac sodium and misoprostol delayed-release tablets are not recommended in women of childbearing potential. Patients must be advised of the abortifacient property and warned not to give the drug to others .

Misoprostol Administration of misoprostol, a component of diclofenac sodium and misoprostol delayed-release tablets, to pregnant women can cause uterine rupture, abortion, premature birth, or birth defects. Uterine rupture has occurred when misoprostol was administered to pregnant women to induce labor or an abortion. Diclofenac sodium and misoprostol delayed-release tablets are contraindicated in pregnant women. Diclofenac sodium and misoprostol delayed-release tablets are not recommended in women of childbearing potential. Patients must be advised of the abortifacient property and warned not to give the drug to others [see Use in Specific Populations (8.1)]. If diclofenac sodium and misoprostol delayed-release tablets are prescribed, verify the pregnancy status of females of reproductive potential prior to initiation of treatment and advise the use effective contraception during treatment with diclofenac sodium and misoprostol delayed-release tablets [see Use in Specific Populations (8.3)]. Diclofenac Premature Closure of Fetal Ductus Arteriosus NSAIDs, including diclofenac, a component of diclofenac sodium and misoprostol delayed-release tablets, increase the risk of premature closure of the fetal ductus arteriosus at about 30 weeks of gestation and later. Oligohydramnios/Neonatal Renal Impairment Use of NSAIDs, including diclofenac, at about 20 weeks gestation or later in pregnancy may cause fetal renal dysfunction leading to oligohydramnios and, in some cases, neonatal renal impairment. These adverse outcomes are seen, on average, after days to weeks of treatment, although oligohydramnios has been infrequently reported as soon as 48 hours after NSAID initiation. Oligohydramnios is often, but not always, reversible with treatment discontinuation. Complications of prolonged oligohydramnios may, for example, include limb contractures and delayed lung maturation. In some postmarketing cases of impaired neonatal renal function, invasive procedures such as exchange transfusion or dialysis were required [see Use in Specific Populations (8.1)].

The following adverse reactions have been identified during post approval of diclofenac sodium and misoprostol delayed-release tablets, diclofenac or misoprostol. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliable estimate their frequency or establish a causal relationship to drug exposure. Body as a whole: death, fever, infection, sepsis, chills, edema. Cardiovascular system: arrhythmia, atrial fibrillation, congestive heart failure, hypertension, hypotension, increased creatine phosphokinase (CPK), increased lactate dehydrogenase (LDH), myocardial infarction, palpitations, phlebitis, premature ventricular contractions, syncope, tachycardia, vasculitis. Central and peripheral nervous system: coma, convulsions, hyperesthesia, hypertonia, hypoesthesia, meningitis, migraine, neuralgia, somnolence, stroke, tremor. Congenital, familial and genetic disorders: birth defects. Digestive: enteritis, GI bleeding, glossitis, heartburn, hematemesis, hemorrhoids, intestinal perforation, stomatitis and ulcerative stomatitis. Female reproductive disorders: intermenstrual bleeding, leukorrhea, vaginitis, uterine cramping, uterine hemorrhage. Hemic and lymphatic system: agranulocytosis, anemia, aplastic anemia, coagulation time increased, ecchymosis, eosinophilia, hemolytic anemia, leukocytosis, lymphadenopathy, pancytopenia, pulmonary embolism, rectal bleeding, thrombocythemia, thrombocytopenia. Hypersensitivity: angioedema, laryngeal/pharyngeal edema, urticaria. Liver and biliary system: abnormal hepatic function, bilirubinemia, liver failure, pancreatitis, hepatitis, jaundice. Male reproductive disorders: impotence, perineal pain. Metabolic and nutritional: blood urea nitrogen (BUN) increased, glycosuria, gout, hypercholesterolemia, hyperglycemia, hyperuricemia, hypoglycemia, periorbital edema, porphyria, weight changes, fluid retention. Pregnancy, puerperium and perinatal conditions: abnormal uterine contractions, uterine rupture/perforation, retained placenta, amniotic fluid embolism, incomplete abortion, premature birth, fetal death. Psychiatric: confusion, disorientation, dream abnormalities, hallucinations, nervousness, paranoia, psychotic reaction. Reproductive system and breast disorders: female fertility decreased. Respiratory system: dyspnea, pneumonia, respiratory depression. Skin and appendages: acne, bruising, erythema multiforme, exfoliative dermatitis, pruritus ani, rash, skin ulceration, Stevens-Johnson syndrome, toxic epidermal necrolysis, cutaneous reactions (bullous eruption). Special senses: hearing impairment, taste loss. Renal and urinary disorders: cystitis, hematuria, interstitial nephritis, micturition frequency, nephrotic syndrome, oliguria, papillary necrosis, renal failure, glomerulonephritis membranous, glomerulonephritis minimal lesion, glomerulonephritis. Vision: amblyopia, blurred vision, conjunctivitis, glaucoma, iritis, lacrimation abnormal, night blindness, vision abnormal.



Risk Summary Diclofenac sodium and misoprostol delayed-release tablets are contraindicated in pregnant women [see Contraindications (4)]. If a woman becomes pregnant while taking diclofenac sodium and misoprostol delayed-release tablets, discontinue the drug and advise the woman of the potential risks to her and to a fetus. There are no adequate and well-controlled studies of diclofenac sodium and misoprostol delayed-release tablets in pregnant women; however, there is information available about the active drug components of diclofenac sodium and misoprostol delayed-release tablets, diclofenac sodium and misoprostol. Administration of misoprostol to pregnant women can cause uterine rupture, abortion, premature birth, or birth defects [see Warnings and Precautions (5.1)]. Congenital anomalies sometimes associated with fetal death have been reported subsequent to the unsuccessful use of misoprostol as an abortifacient, but the drug’s teratogenic mechanism has not been demonstrated. Use of NSAIDS, including diclofenac a component of diclofenac sodium and misoprostol delayed-release tablets, can cause premature closure of the fetal ductus arteriosus and fetal renal dysfunction leading to oligohydramnios and, in some cases, neonatal renal impairment (see Data). There are clinical considerations when misoprostol and diclofenac are used in pregnant women (see Clinical Considerations). In reproduction studies with pregnant rabbits, there were no skeletal or visceral malformations when the combination of diclofenac sodium and misoprostol was administered during organogenesis at doses less than the maximum recommended human doses (MRHD); however, embryotoxicity was observed at this exposure (see Data). Based on animal data, prostaglandins have been shown to have an important role in endometrial vascular permeability, blastocyst implantation, and decidualization. In animal studies, administration of prostaglandin synthesis inhibitors such as diclofenac, resulted in increased pre- and post-implantation loss. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. The estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Maternal Adverse Reactions Misoprostol may produce uterine contractions, uterine bleeding, and expulsion of the products of conception. Misoprostol has been used to ripen the cervix, to induce labor, and to treat postpartum hemorrhage, outside of its approved indication. A major adverse effect of these uses is hyperstimulation of the uterus. Uterine rupture, amniotic fluid embolism, severe bleeding, shock, and maternal death have been reported when misoprostol was administered to pregnant women to induce labor to induce abortion beyond the eighth week of pregnancy. Higher doses of misoprostol, including the 100 mcg tablet, may increase the risk of complications from uterine hyperstimulation. Diclofenac sodium and misoprostol delayed-release tablets, which contains 200 mcg of misoprostol, is likely to have a greater risk of uterine hyperstimulation than the 100 mcg tablet of misoprostol. Abortions caused by misoprostol may be incomplete. Cases of amniotic fluid embolism, which resulted in maternal and fetal death, have been reported with use of misoprostol during pregnancy. Severe vaginal bleeding, retained placenta, shock, and pelvic pain have also been reported. These women were administered misoprostol vaginally and/or orally over a range of doses. Diclofenac sodium and misoprostol delayed-release tablets are contraindicated in pregnant women [see Contraindications (4) ]. If a woman is or becomes pregnant while taking this drug, the drug should be discontinued and the patient apprised of the potential hazard to the fetus. Fetal/Neonatal Adverse Reactions Misoprostol Misoprostol may endanger pregnancy (may cause abortion) and thereby cause harm to the fetus when administered to a pregnant woman. Use of misoprostol for the induction of labor in the third trimester was associated with uterine hyperstimulation with resulting changes in the fetal heart rate (fetal bradycardia) and fetal death (misoprostol is not approved for this use). Diclofenac sodium and misoprostol delayed-release tablets are contraindicated in pregnant women [see Contraindications (4) ]. Diclofenac Premature Closure of Fetal Ductus Arteriosus: NSAIDs, including diclofenac, can cause premature closure of the fetal ductus arteriosus at about 30 weeks gestation and later in pregnancy (see Data). Oligohydramnios/Neonatal Renal Impairment: Use of NSAIDs, including diclofenac, at about 20 weeks gestation or later in pregnancy has been associated with cases of fetal renal dysfunction leading to oligohydramnios, and in some cases, neonatal renal impairment (see Data). Labor or Delivery There are no studies on the effects of diclofenac sodium and misoprostol delayed-release tablets or diclofenac during labor or delivery. In animal studies, NSAIDS, including diclofenac, inhibit prostaglandin synthesis, cause delayed parturition, and increase the incidence of stillbirth. In humans, some case reports and studies have associated misoprostol with risk of stillbirth, uterine hyperstimulation, perineal tear, amniotic fluid embolism, severe bleeding, shock, uterine rupture and death. The risk of uterine rupture associated with misoprostol use in pregnancy may occur at any gestational age, and increases with advancing gestational age and with prior uterine surgery, including cesarean delivery. Grand multiparity also appears to be a risk factor for uterine rupture. Data Human Data Misoprostol Several reports in the literature associate the use of misoprostol during the first trimester of pregnancy with skull defects, cranial nerve palsies, facial malformations, and limb defects. Diclofenac Data from observational studies regarding potential embryo-fetal risks of NSAID use (including diclofenac) in the first or second trimesters of pregnancy are inconclusive.  Premature Closure of Fetal Ductus Arteriosus: Published literature reports that the use of NSAIDs at about 30 weeks of gestation and later in pregnancy may cause premature closure of the fetal ductus arteriosus. Oligohydramnios/Neonatal Renal Impairment: Published studies and postmarketing reports describe maternal NSAID use at about 20 weeks gestation or later in pregnancy associated with fetal renal dysfunction leading to oligohydramnios, and in some cases, neonatal renal impairment. These adverse outcomes are seen, on average, after days to weeks of treatment, although oligohydramnios has been infrequently reported as soon as 48 hours after NSAID initiation. In many cases, but not all, the decrease in amniotic fluid was transient and reversible with cessation of the drug. There have been a limited number of case reports of maternal NSAID use and neonatal renal dysfunction without oligohydramnios, some of which were irreversible. Some cases of neonatal renal dysfunction required treatment with invasive procedures, such as exchange transfusion or dialysis. Methodological limitations of these postmarketing studies and reports include lack of a control group; limited information regarding dose, duration, and timing of drug exposure; and concomitant use of other medications. These limitations preclude establishing a reliable estimate of the risk of adverse fetal and neonatal outcomes with maternal NSAID use. Because the published safety data on neonatal outcomes involved mostly preterm infants, the generalizability of certain reported risks to the full-term infant exposed to NSAIDs through maternal use is uncertain. Animal Data The reproductive and developmental effects of both the combination of diclofenac sodium and misoprostol and each component of diclofenac sodium and misoprostol delayed-release tablets alone have been studied in animals. In all studies there was no evidence of teratogenicity. In an oral teratology study in pregnant rabbits, diclofenac sodium and misoprostol delayed-release tablets was administered at dose combinations  (diclofenac and misoprostol, 250:1 ratio) up to 10 mg/kg/day diclofenac sodium (120 mg/m2/day, 0.8 times the MRHD based on body surface area) and 0.04 mg/kg/day misoprostol (0.48 mg/m2/day, 0.8 times the MRHD based on body surface area) and there was no evidence of teratogenicity. At the high dose, there was evidence of embryotoxicity (resorption and decreased fetal body weight) and maternal toxicity (decreased food intake and weight gain). In oral teratology studies with misoprostol in pregnant rats at doses up to 1.6 mg/kg/day (9.6 mg/m2/day, 16 times the MRHD based on body surface area) and pregnant rabbits at doses up to 1.0 mg/kg/day (12 mg/m2/day, 20 times the MRHD based on body surface area), there was no evidence of teratogenicity. In oral teratology studies with diclofenac sodium in pregnant mice at doses up to 20 mg/kg/day (60 mg/m2/day, 0.4 times the MRHD based on body surface area), pregnant rats at doses up to 10 mg/kg/day (60 mg/m2/day, 0.4 times the MRHD based on body surface area) and pregnant rabbits at doses up to 10 mg/kg/day (120 mg/m2/day, 0.8 times the MRHD based on body surface area), there was no evidence of teratogenicity.

Diclofenac sodium and misoprostol delayed-release tablets are not recommended in women of childbearing potential [see Warnings and Precautions (5.1)]. If diclofenac sodium and misoprostol delayed-release tablets are prescribed, patients must be advised of the abortifacient property and warned not to give the drug to others. Pregnancy Testing Verify pregnancy status for females of reproductive potential within 2 weeks prior to initiating diclofenac sodium and misoprostol delayed-release tablets. Contraception Females Diclofenac sodium and misoprostol delayed-release tablets can cause fetal harm when administered to a pregnant woman [see Contraindications (4) and Use in Specific Populations (8.1)]. Advise females of reproductive potential to use effective contraception during treatment with diclofenac sodium and misoprostol delayed-release tablets. Diclofenac sodium and misoprostol delayed-release tablets may be prescribed if the patient: has had a negative serum pregnancy test within 2 weeks prior to beginning therapy. is capable of complying with effective contraceptive measures. has received both oral and written warnings of the hazards of misoprostol, the risk of possible contraception failure, and the danger to other women of childbearing potential should the drug be taken by mistake. will begin diclofenac sodium and misoprostol delayed-release tablets only on the second or third day of the next normal menstrual period. Advise females to inform their healthcare provider of a known or suspected pregnancy. Infertility Females Based on the mechanism of action, the use of prostaglandin-mediated NSAIDs, including diclofenac, a component of diclofenac sodium and misoprostol delayed-release tablets, may delay or prevent rupture of ovarian follicles, which has been associated with reversible infertility in some women [see Clinical Pharmacology (12.1) ]. Published animal studies have shown that administration of prostaglandin synthesis inhibitors has the potential to disrupt prostaglandin-mediated follicular rupture required for ovulation. Small studies in women treated with NSAIDs have also shown a reversible delay in ovulation. Consider withdrawal of NSAIDs, including diclofenac sodium and misoprostol delayed-release tablets, in women who have difficulties conceiving or who are undergoing investigation of infertility.

General Pharmacokinetic Characteristics The pharmacokinetic profiles of diclofenac and misoprostol administered as the fixed combination diclofenac sodium and misoprostol delayed-release tablets, 50 mg/0.2 mg or diclofenac sodium and misoprostol delayed-release tablets, 75 mg/0.2 mg are similar to the profiles when the two drugs are administered as separate tablets (see Table 2). No pharmacokinetic interaction between the two drugs has been observed following multiple dosing. The diclofenac total exposure [area under the curve (AUC)] is dose-proportional within the range of 25 mg to 150 mg. Approximately dose-proportional increase in misoprostol exposure was also observed within the range of 200 mcg to 400 mcg. Neither diclofenac nor misoprostol accumulated in plasma following repeated doses of diclofenac sodium and misoprostol delayed-release tablets given every 12 hours under fasted conditions. Table 2: Pharmacokinetic Parameters of Diclofenac and Misoprostol Acid Following Single Oral Doses of Diclofenac Sodium and Misoprostol Delayed-Release Tablets or Separate Products in Healthy Subjects MISOPROSTOL ACID Mean (SD) Treatment (n=36) Cmax (pg/mL) Tmax (hr) AUC(0–4h) (pg·hr/mL) Diclofenac Sodium and Misoprostol Delayed-Release Tablets 50 mg/0.2 mg 441 (137) 0.30 (0.13) 266 (95) Misoprostol 478 (201) 0.30 (0.10) 295 (143) Diclofenac Sodium and Misoprostol Delayed-Release Tablets 75 mg/0.2 mg 304 (110) 0.26 (0.09) 177 (49) Misoprostol 290 (130) 0.35 (0.12) 176 (58) DICLOFENAC Mean (SD) Treatment (n=36) Cmax (ng/mL) Tmax (hr) AUC(0–12h) (ng·hr/mL) Diclofenac Sodium and Misoprostol Delayed-Release Tablets 50 mg/0.2 mg 1207 (364) 2.4 (1.0) 1380 (272) Diclofenac Sodium 1298 (441) 2.4 (1.0) 1357 (290) Diclofenac Sodium and Misoprostol Delayed-Release Tablets 75 mg/0.2 mg 2025 (2005) 2.0 (1.4) 2773 (1347) Diclofenac Sodium 2367 (1318) 1.9 (0.7) 2609 (1185) SD: Standard deviation of the mean; AUC: Area under the curve; Cmax: Peak concentration; Tmax: Time to peak concentration Absorption Diclofenac: Diclofenac is completely absorbed from the GI tract after oral administration under fasted condition, and peak plasma levels are achieved in 2 hours (range 1 to 4 hours), and the area under the plasma concentration curve (AUC) is dose-proportional within the range of 25 mg to 150 mg. Peak plasma levels are less than dose-proportional and are approximately 1.5 and 2.0 mcg/mL for 50 mg and 75 mg doses, respectively. The diclofenac in diclofenac sodium and misoprostol delayed-release tablets is in a pharmaceutical formulation that resists dissolution in the low pH of gastric fluid but allows a rapid release of drug in the higher pH environment of the duodenum. Only 50% of the absorbed dose is systemically available due to first pass metabolism (i.e., oral bioavailability is 50%). Misoprostol: Misoprostol is rapidly absorbed following oral administration of diclofenac sodium and misoprostol delayed-release tablets, and misoprostol acid (active metabolite) reaches a maximum plasma concentration in approximately 20 minutes. Maximum plasma concentrations of misoprostol acid are diminished when the dose is taken with food, and total availability of misoprostol acid is reduced by use of concomitant antacid. Clinical trials were conducted with concomitant antacid; this effect does not appear to be clinically important. Food decreases the multiple-dose bioavailability profile of diclofenac sodium and misoprostol delayed-release tablets, 50 mg/0.2 mg and diclofenac sodium and misoprostol delayed-release tablets, 75 mg/0.2 mg. Distribution Diclofenac: The volume of distribution of diclofenac is approximately 0.55 L/kg. More than 99% of diclofenac is bound to plasma albumin. Misoprostol: The plasma protein binding of misoprostol acid is less than 90% and is concentration-independent in the therapeutic range. After a single oral dose of misoprostol to nursing mothers, misoprostol acid was excreted in breast milk. The maximum concentration of misoprostol acid in expressed breast milk was achieved within 1 hour after dosing and was 7.6 pg/mL (CV 37%) and 20.9 pg/mL (CV 77%) after single 200 mcg and 600 mcg misoprostol administration, respectively. The misoprostol acid concentrations in breast milk declined to <1 pg/mL at 5 hours post-dose. These data may not reflect drug level in mature milk and in a daily dosing regimen for osteoarthritis or rheumatoid arthritis. Elimination Metabolism Diclofenac : Metabolism is predominantly mediated via CYP2C9 in the liver. Five metabolites (4'hydroxy-, 5-hydroxy-, 3'-hydroxy-, 4',5-dihydroxy- and 3'-hydroxy-4'-methoxy diclofenac) have been identified. The major metabolite (4'-hydroxy-diclofenac) has very weak pharmacologic activity. Both diclofenac and its oxidative metabolites undergo glucuronidation or sulfation followed by biliary excretion. Acylglucuronidation mediated by UGT2B7 and oxidation mediated by CYP2C8 may also play a role in diclofenac metabolism. CYP3A4 is responsible for the formation of minor metabolites, 5-hydroxy and 3'-hydroxy-diclofenac. Misoprostol : Undergoes rapid and extensive metabolism to its biologically active metabolite, misoprostol acid. Excretion Diclofenac : Diclofenac is eliminated through metabolism and subsequent urinary and biliary excretion of the glucuronide and the sulfate conjugates of the metabolites. Approximately 65% of the dose is excreted in the urine and 35% in the bile. The elimination half-life of diclofenac is approximately 2 hours. The clearance of diclofenac is approximately 350 mL/min (equivalent to 21 L/h). Conjugates of unchanged diclofenac account for 5% to 10% of the dose excreted in the urine and for less than 5% excreted in the bile. Little or no unchanged unconjugated drug is excreted. Conjugates of the principal metabolite account for 20% to 30% of the dose excreted in the urine and for 10% to 20% of the dose excreted in the bile. Conjugates of three other metabolites together account for 10% to 20% of the dose excreted in the urine and for small amounts excreted in the bile. The elimination half-life values for these metabolites are shorter than those for the parent drug. Urinary excretion of an additional metabolite (half-life = 80 hours) accounts for only 1.4% of the oral dose. The degree of accumulation of diclofenac metabolites is unknown. Some of the metabolites may have activity. Misoprostol : After oral administration of radio-labeled misoprostol, approximately 70% of detected radioactivity appears in the urine. The elimination half-life is approximately 30 minutes. Specific Populations Geriatric Patients No differences in the pharmacokinetics of diclofenac were observed in geriatric subjects (66 to 81 years; N=10) compared to younger adult subjects (26 to 46 years; N=10) following administration of diclofenac 50 mg twice daily for 4 weeks. Though the mean AUC value of misoprostol acid for elderly subjects was 41% higher in geriatric healthy subjects (mean age, 69.5±4.6 years, N=24) compared to younger adult healthy subjects (mean age, 25.4±4.2 years, N=24) following single dose of misoprostol 400 mcg, the increase in exposure is not clinically meaningful. In a multiple-dose crossover study of diclofenac sodium and misoprostol delayed-release tablets administered twice daily to 24 subjects aged 65 years of age and older, misoprostol did not affect the pharmacokinetics of diclofenac [see Use in Specific Populations (8.5)]. Racial or Ethnic Groups Pharmacokinetic differences due to race have not been identified. Patients with Renal Impairment In patients with renal impairment (N=5, creatinine clearance 3 to 42 mL/min) following intravenous administration of 50 mg diclofenac, AUC values and elimination rates were comparable to those in healthy subjects. Pharmacokinetic studies with misoprostol in patients with severe renal impairment requiring hemodialysis (n=8, mean creatinine clearance 6.2±3.3 mL/min/1.73m2) who received a single dose of 400 mcg misoprostol during a interdialytic period showed an approximate doubling of elimination half-life, Cmax, and AUC of misoprostol acid compared to healthy subjects [see Use in Specific Populations (8.6)]. Patients with Hepatic Impairment In patients with biopsy-confirmed cirrhosis or chronic active hepatitis (variably elevated transaminases and mildly elevated bilirubin, N=10), diclofenac concentrations and urinary elimination values following administration of 100 mg oral solution were comparable to those in healthy subjects. In a study of subjects with mild to moderate hepatic impairment, mean misoprostol acid AUC and Cmax showed approximately twice high as the mean values obtained in healthy subjects. Three subjects who had the lowest antipyrine and lowest indocyanine green clearance values had the highest misoprostol acid AUC and Cmax values. Drug Interaction Studies Diclofenac Aspirin : When diclofenac sodium and misoprostol delayed-release tablets was administered with aspirin, the protein binding of diclofenac was reduced, although the clearance of the free diclofenac was not altered. The clinical significance of this interaction is not known. See Table 1 for clinically significant drug interactions of NSAIDs with aspirin [see Drug Interactions (7)]. Voriconazole : When a single dose diclofenac (50 mg) was coadministered with the last dose of voriconazole (400 mg every 12 hours on Day 1, followed by 200 mg every 12 hours on Day 2), the mean Cmax and AUC of diclofenac were increased by 114% and 78%, respectively, when compared to diclofenac alone [see Drug Interactions (7)]. In vitro, diclofenac interferes minimally with the protein binding of prednisolone (10% decrease in binding). Benzylpenicillin, ampicillin, oxacillin, chlortetracycline, doxycycline, cephalothin, erythromycin, and sulfamethoxazole have no influence, in vitro, on the protein binding of diclofenac in human serum. Other drugs : In small groups of patients (7 to 10 patients/interaction study), the concomitant administration of azathioprine, gold, chloroquine, D-penicillamine, prednisolone, doxycycline or digitoxin did not significantly affect Cmax and AUC of diclofenac. Misoprostol Diazepam : Misoprostol given for 1 week had no effect on the steady state pharmacokinetics of diazepam when the two drugs were administered 2 hours apart. Other drugs : Pharmacokinetic studies also showed a lack of drug interaction with antipyrine or propranolol given with misoprostol.