Arthrotec

Name: Arthrotec

What is diclofenac and misoprostol?

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID). It works by reducing substances in the body that cause pain and inflammation.

Misoprostol reduces stomach acid and replaces protective substances in the stomach that are reduced by NSAIDs.

Diclofenac and misoprostol is a combination medicine used to treat osteoarthritis and rheumatoid arthritis in people at high risk for developing stomach or intestinal ulcers.

Diclofenac and misoprostol may also be used for purposes not listed in this medication guide.

What do I need to tell my doctor BEFORE I take Arthrotec?

  • If you have an allergy to diclofenac, misoprostol, or any other part of Arthrotec.
  • If you have an allergy to aspirin or NSAIDs.
  • If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
  • If you have any of these health problems: GI (gastrointestinal) bleeding or kidney problems.
  • If you are having your fertility checked.
  • If you are taking any other NSAID.
  • If you are taking a salicylate drug like aspirin.
  • If you are taking pemetrexed.

This is not a list of all drugs or health problems that interact with this medicine.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take Arthrotec with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

If OVERDOSE is suspected

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Indications and Usage for Arthrotec

Arthrotec is indicated for treatment of the signs and symptoms of osteoarthritis or rheumatoid arthritis in patients at high risk of developing NSAID-induced gastric and duodenal ulcers and their complications. For a list of factors that may increase the risk of NSAID-induced gastric and duodenal ulcers and their complications [see Warnings and Precautions (5.2)].

Warnings and Precautions

Cardiovascular Thrombotic Events

Clinical trials of several COX-2 selective and nonselective NSAIDs of up to three years duration have shown an increased risk of serious cardiovascular (CV) thrombotic events, including myocardial infarction (MI) and stroke, which can be fatal. Based on available data, it is unclear that the risk for CV thrombotic events is similar for all NSAIDs. The relative increase in serious CV thrombotic events over baseline conferred by NSAID use appears to be similar in those with and without known CV disease or risk factors for CV disease. However, patients with known CV disease or risk factors had a higher absolute incidence of excess serious CV thrombotic events, due to their increased baseline rate. Some observational studies found that this increased risk of serious CV thrombotic events began as early as the first weeks of treatment. The increase in CV thrombotic risk has been observed most consistently at higher doses.

To minimize the potential risk for an adverse CV event in NSAID-treated patients, use the lowest effective dose for the shortest duration possible. Physicians and patients should remain alert for the development of such events, throughout the entire treatment course, even in the absence of previous CV symptoms. Patients should be informed about the symptoms of serious CV events and the steps to take if they occur.

There is no consistent evidence that concurrent use of aspirin mitigates the increased risk of serious CV thrombotic events associated with NSAID use. The concurrent use of aspirin and an NSAID, such as diclofenac, increases the risk of serious gastrointestinal (GI) events [see Warnings and Precautions (5.2)].

Status Post Coronary Artery Bypass Graft (CABG) Surgery

Two large, controlled clinical trials of a COX-2 selective NSAID for the treatment of pain in the first 10–14 days following CABG surgery found an increased incidence of myocardial infarction and stroke. NSAIDs are contraindicated in the setting of CABG [see Contraindications (4)].

Post-MI Patients

Observational studies conducted in the Danish National Registry have demonstrated that patients treated with NSAIDs in the post-MI period were at increased risk of reinfarction, CV-related death, and all-cause mortality beginning in the first week of treatment. In this same cohort, the incidence of death in the first year post-MI was 20 per 100 person years in NSAID-treated patients compared to 12 per 100 person years in non-NSAID exposed patients. Although the absolute rate of death declined somewhat after the first year post-MI, the increased relative risk of death in NSAID users persisted over at least the next four years of follow-up.

Avoid the use of Arthrotec in patients with a recent MI unless the benefits are expected to outweigh the risk of recurrent CV thrombotic events. If Arthrotec is used in patients with a recent MI, monitor patients for signs of cardiac ischemia.

Gastrointestinal Bleeding, Ulceration, and Perforation

NSAIDs, including diclofenac, cause serious gastrointestinal (GI) adverse events including inflammation, bleeding, ulceration, and perforation of the esophagus, stomach, small intestine, or large intestine, which can be fatal. These serious adverse events can occur at any time, with or without warning symptoms, in patients treated with NSAIDs. Only one in five patients who develop a serious upper GI adverse event on NSAID therapy is symptomatic. Upper GI ulcers, gross bleeding, or perforation caused by NSAIDs occurred in approximately 1% of patients treated for 3–6 months, and in about 2%–4% of patients treated for one year. However, even short-term NSAID therapy is not without risk.

Risk Factors for GI Bleeding, Ulceration, and Perforation

Patients with a prior history of peptic ulcer disease and/or GI bleeding who used NSAIDs had a greater than 10-fold increased risk for developing a GI bleed compared to patients without these risk factors. Other factors that increase the risk of GI bleeding in patients treated with NSAIDs include longer duration of NSAID therapy; concomitant use of oral corticosteroids, aspirin, anticoagulants, or selective serotonin reuptake inhibitors (SSRIs); smoking; use of alcohol; older age; and poor general health status. Most postmarketing reports of fatal GI events occurred in elderly or debilitated patients. Additionally, patients with advanced liver disease and/or coagulopathy are at increased risk for GI bleeding.

Strategies to Minimize the GI Risks in NSAID-treated patients:

  • Use the lowest effective dosage for the shortest possible duration.
  • Avoid administration of more than one NSAID at a time.
  • Avoid use in patients at high risk unless benefits are expected to outweigh the increased risk of bleeding. For such patients, as well as those with active GI bleeding, consider alternate therapies other than NSAIDs.
  • Remain alert for signs and symptoms of GI ulceration and bleeding during NSAID therapy.
  • If a serious GI adverse event is suspected, promptly initiate evaluation and treatment, and discontinue Arthrotec until a serious GI adverse event is ruled out.
  • In the setting of concomitant use of low-dose aspirin for cardiac prophylaxis, monitor patients more closely for evidence of GI bleeding [see Drug Interactions (7)].

Hepatotoxicity

In clinical trials with Arthrotec, meaningful elevation of ALT (SGPT, more than 3 times the ULN [ULN = the upper limit of the normal range]) occurred in 1.6% of 2,184 patients treated with Arthrotec and in 1.4% of 1,691 patients treated with diclofenac sodium. These increases were generally transient, and enzyme levels returned to within the normal range upon discontinuation of therapy with Arthrotec. The misoprostol component of Arthrotec does not appear to exacerbate the hepatic effects caused by the diclofenac sodium component.

In clinical trials of diclofenac-containing products, meaningful elevations (i.e., more than 3 times the ULN) of AST (SGOT) occurred in about 2% of approximately 5,700 patients at some time during diclofenac treatment (ALT was not measured in all studies).

In a large, open-label, controlled trial of 3,700 patients treated with oral diclofenac sodium for 2–6 months, patients were monitored first at 8 weeks and 1,200 patients were monitored again at 24 weeks. Meaningful elevations of ALT and/or AST occurred in about 4% of patients and included marked elevations (i.e., greater than 8 times the ULN) in about 1% of the 3,700 patients. In that open-label study, a higher incidence of borderline (less than 3 times the ULN), moderate (3–8 times the ULN), and marked (greater than 8 times the ULN) elevations of ALT or AST was observed in patients receiving diclofenac when compared to other NSAIDs. Elevations in transaminases were seen more frequently in patients with osteoarthritis than in those with rheumatoid arthritis.

Almost all meaningful elevations in transaminases were detected before patients became symptomatic. Abnormal tests occurred during the first 2 months of therapy with diclofenac in 42 of the 51 patients in all trials who developed marked transaminase elevations.

In postmarketing reports, cases of drug-induced hepatotoxicity have been reported in the first month, and in some cases, the first 2 months of therapy, but can occur at any time during treatment with diclofenac. Postmarketing surveillance has reported cases of severe hepatic reactions, including liver necrosis, jaundice, fulminant hepatitis with and without jaundice, and liver failure. Some of these reported cases resulted in fatalities or liver transplantation.

In a European retrospective population-based, case-controlled study, 10 cases of diclofenac associated drug-induced liver injury with current use compared with non-use of diclofenac were associated with a statistically significant 4-fold adjusted odds ratio of liver injury. In this particular study, based on an overall number of 10 cases of liver injury associated with diclofenac, the adjusted odds ratio increased further with female gender, doses of 150 mg or more, and duration of use for more than 90 days.

Physicians should measure transaminases at baseline and periodically in patients receiving long-term therapy with diclofenac, because severe hepatotoxicity may develop without a prodrome of distinguishing symptoms. The optimum times for making the first and subsequent transaminase measurements are not known. Based on clinical trial data and postmarketing experiences, transaminases should be monitored within 4 to 8 weeks after initiating treatment with diclofenac. However, severe hepatic reactions can occur at any time during treatment with diclofenac.

If abnormal liver tests persist or worsen, if clinical signs and/or symptoms consistent with liver disease develop, or if systemic manifestations occur (e.g., eosinophilia, rash, abdominal pain, diarrhea, dark urine, etc.), Arthrotec should be discontinued immediately.

Inform patients of the warning signs and symptoms of hepatotoxicity (e.g., nausea, fatigue, lethargy, diarrhea, pruritus, jaundice, right upper quadrant tenderness, and "flu-like" symptoms). If clinical signs and symptoms consistent with liver disease develop, or if systemic manifestations occur (e.g., eosinophilia, rash, etc.), discontinue Arthrotec immediately, and perform a clinical evaluation of the patient.

To minimize the potential risk for an adverse liver related event in patients treated with Arthrotec, the lowest effective dose should be used for the shortest duration possible. Exercise caution when prescribing Arthrotec with concomitant drugs that are known to be potentially hepatotoxic (e.g., antibiotics, anti-epileptics).

Hypertension

NSAIDs, including Arthrotec, can lead to new onset of hypertension or worsening of pre-existing hypertension, either of which may contribute to the increased incidence of CV events. Patients taking angiotensin converting enzyme (ACE) inhibitors, thiazide diuretics, or loop diuretics may have impaired response to these therapies when taking NSAIDs [see Drug Interactions (7)].

Monitor blood pressure (BP) during the initiation of NSAID treatment and throughout the course of therapy.

Heart Failure and Edema

The Coxib and traditional NSAID Trialists' Collaboration meta-analysis of randomized controlled trials demonstrated an approximately two-fold increase in hospitalizations for heart failure in COX-2 selective-treated patients and nonselective NSAID-treated patients compared to placebo-treated patients. In a Danish National Registry study of patients with heart failure, NSAID use increased the risk of MI, hospitalization for heart failure, and death.

Additionally, fluid retention and edema have been observed in some patients treated with NSAIDs. Use of diclofenac may blunt the CV effects of several therapeutic agents used to treat these medical conditions (e.g., diuretics, ACE inhibitors, or angiotensin receptor blockers [ARBs]) [see Drug Interactions (7)].

Avoid the use of Arthrotec in patients with severe heart failure unless the benefits are expected to outweigh the risk of worsening heart failure. If Arthrotec is used in patients with severe heart failure, monitor patients for signs of worsening heart failure.

Renal Toxicity and Hyperkalemia

Renal Toxicity

Long-term administration of NSAIDs has resulted in renal papillary necrosis and other renal injury. Renal toxicity has also been seen in patients in whom renal prostaglandins have a compensatory role in the maintenance of renal perfusion. In these patients, administration of an NSAID may cause a dose-dependent reduction in prostaglandin formation and, secondarily, in renal blood flow, which may precipitate overt renal decompensation. Patients at greatest risk of this reaction are those with impaired renal function, dehydration, hypovolemia, heart failure, liver dysfunction, those taking diuretics and ACE inhibitors or ARBs, and the elderly. Discontinuation of NSAID therapy is usually followed by recovery to the pretreatment state.

No information is available from controlled clinical studies regarding the use of Arthrotec in patients with advanced renal disease. The renal effects of Arthrotec may hasten the progression of renal dysfunction in patients with pre-existing renal disease.

Correct volume status in dehydrated or hypovolemic patients prior to initiating Arthrotec. Monitor renal function in patients with renal or hepatic impairment, heart failure, dehydration, or hypovolemia during use of Arthrotec [see Drug Interactions (7)]. Avoid the use of Arthrotec in patients with advanced renal disease unless the benefits are expected to outweigh the risk of worsening renal function. If Arthrotec is used in patients with advanced renal disease, monitor patients for signs of worsening renal function.

Hyperkalemia

Increases in serum potassium concentration, including hyperkalemia, with use of NSAIDs, even in some patients without renal impairment. In patients with normal renal function, these effects have been attributed to a hyporeninemic-hypoaldosteronism state.

Anaphylactic Reactions

Diclofenac/misoprostol has been associated with anaphylactic reactions in patients with and without known hypersensitivity to diclofenac/misoprostol and in patients with aspirin-sensitive asthma [see Contraindications (4) and Warnings and Precautions (5.8)].

Seek emergency help if an anaphylactic reaction occurs.

Exacerbation of Asthma Related to Aspirin Sensitivity

A subpopulation of patients with asthma may have aspirin-sensitive asthma which may include chronic rhinosinusitis complicated by nasal polyps; severe, potentially fatal bronchospasm; and/or intolerance to aspirin and other NSAIDs. Because cross-reactivity between aspirin and other NSAIDs has been reported in such aspirin-sensitive patients, Arthrotec is contraindicated in patients with this form of aspirin sensitivity [see Contraindications (4)]. When Arthrotec is used in patients with preexisting asthma (without known aspirin sensitivity), monitor patients for changes in the signs and symptoms of asthma.

Serious Skin Reactions

NSAIDs, including diclofenac, can cause serious skin adverse reactions such as exfoliative dermatitis, Stevens-Johnson Syndrome (SJS), and toxic epidermal necrolysis (TEN), which can be fatal. These serious events may occur without warning. Inform patients about the signs and symptoms of serious skin reactions, and to discontinue the use of Arthrotec at the first appearance of skin rash or any other sign of hypersensitivity. Arthrotec is contraindicated in patients with previous serious skin reactions to NSAIDs [see Contraindications (4)].

Premature Closure of Fetal Ductus Arteriosus

Diclofenac may cause premature closure of the fetal ductus arteriosus. Arthrotec is contraindicated in pregnant women. Advise pregnant women of the potential risk to a fetus. Verify the pregnancy status of females of reproductive potential prior to initiation of ARTHOTEC. Advise females of reproductive potential to use effective contraception during treatment with Arthrotec [see Contraindications (4) and Use in Specific Populations (8.1, 8.3)].

Hematologic Toxicity

Anemia has occurred in NSAID-treated patients. This may be due to occult or gross blood loss, fluid retention, or an incompletely described effect on erythropoiesis. If a patient treated with Arthrotec has any signs or symptoms of anemia, monitor hemoglobin or hematocrit.

NSAIDs, including Arthrotec, may increase the risk of bleeding events. Co-morbid conditions such as coagulation disorders or concomitant use of warfarin and other anticoagulants, antiplatelet agents (e.g., aspirin), and serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) may increase this risk. Monitor these patients for signs of bleeding [see Drug Interactions (7)].

Masking of Inflammation and Fever

The pharmacological activity of Arthrotec in reducing inflammation, and possibly fever, may diminish the utility of diagnostic signs in detecting infections.

Laboratory Monitoring

Because serious GI bleeding, hepatotoxicity, and renal injury can occur without warning symptoms or signs, consider monitoring patients on long-term NSAID treatment with a CBC and a chemistry profile periodically [see Warnings and Precautions (5.2, 5.6)].

Drug Interactions

See Table 1 for clinically significant drug interactions with diclofenac/misoprostol.

Table 1: Clinically Significant Drug Interactions with Diclofenac/Misoprostol
Drugs That Interfere with Hemostasis
Clinical Impact:
  • Diclofenac and anticoagulants such as warfarin have a synergistic effect on bleeding. The concomitant use of diclofenac and anticoagulants have an increased risk of serious bleeding compared to the use of either drug alone.
  • Serotonin release by platelets plays an important role in hemostasis. Case-control and cohort epidemiological studies showed that concomitant use of drugs that interfere with serotonin reuptake and an NSAID may potentiate the risk of bleeding more than an NSAID alone.
Intervention: Monitor patients with concomitant use of Arthrotec with anticoagulants (e.g., warfarin), antiplatelet agents (e.g., aspirin), selective serotonin reuptake inhibitors (SSRIs), and serotonin norepinephrine reuptake inhibitors (SNRIs) for signs of bleeding [see Warnings and Precautions (5.11)].
Aspirin
Clinical Impact: Controlled clinical studies showed that the concomitant use of NSAIDs and analgesic doses of aspirin does not produce any greater therapeutic effect than the use of NSAIDs alone. In a clinical study, the concomitant use of an NSAID and aspirin was associated with a significantly increased incidence of GI adverse reactions as compared to use of the NSAID alone [see Warnings and Precautions (5.2)].
Intervention: Concomitant use of Arthrotec and analgesic doses of aspirin is not generally recommended because of the increased risk of bleeding [see Warnings and Precautions (5.11)].
Arthrotec is not a substitute for low dose aspirin for cardiovascular protection.
ACE Inhibitors, Angiotensin Receptor Blockers, and Beta-Blockers
Clinical Impact:
  • NSAIDs may diminish the antihypertensive effect of angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), or beta-blockers (including propranolol).
  • In patients who are elderly, volume-depleted (including those on diuretic therapy), or have renal impairment, co-administration of an NSAID with ACE inhibitors or ARBs may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible.
Intervention:
  • The concomitant administration of these drugs should be done with caution. Patients should be adequately hydrated and the clinical need to monitor the renal function should be assessed at the beginning of the concomitant treatment and periodically thereafter.
  • During concomitant use of Arthrotec and ACE-inhibitors, ARBs, or beta-blockers, monitor blood pressure to ensure that the desired blood pressure is obtained.
  • During concomitant use of Arthrotec and ACE-inhibitors or ARBs in patients who are elderly, volume-depleted, or have impaired renal function, monitor for signs of worsening renal function [see Warnings and Precautions (5.6)].
Diuretics
Clinical Impact: Clinical studies, as well as post-marketing observations, showed that NSAIDs reduced the natriuretic effect of loop diuretics (e.g., furosemide) and thiazide diuretics in some patients. This effect has been attributed to the NSAID inhibition of renal prostaglandin synthesis.
Intervention: During concomitant use of Arthrotec with diuretics, observe patients for signs of worsening renal function, in addition to assuring diuretic efficacy including antihypertensive effects [see Warnings and Precautions (5.6)].
Digoxin
Clinical Impact: The concomitant use of diclofenac with digoxin has been reported to increase the serum concentration and prolong the half-life of digoxin.
Intervention: During concomitant use of Arthrotec and digoxin, monitor serum digoxin levels.
Lithium
Clinical Impact: NSAIDs have produced elevations in plasma lithium levels and reductions in renal lithium clearance. The mean minimum lithium concentration increased 15%, and the renal clearance decreased by approximately 20%. This effect has been attributed to NSAID inhibition of renal prostaglandin synthesis.
Intervention: During concomitant use of Arthrotec and lithium, monitor patients for signs of lithium toxicity.
Methotrexate
Clinical Impact: Concomitant use of NSAIDs and methotrexate may increase the risk for methotrexate toxicity (e.g., neutropenia, thrombocytopenia, renal dysfunction).
Intervention: During concomitant use of Arthrotec and methotrexate, monitor patients for methotrexate toxicity.
Cyclosporine
Clinical Impact: Concomitant use of diclofenac and cyclosporine may increase cyclosporine's nephrotoxicity.
Intervention: During concomitant use of Arthrotec and cyclosporine, monitor patients for signs of worsening renal function.
NSAIDs and Salicylates
Clinical Impact: Concomitant use of diclofenac with other NSAIDs or salicylates (e.g., diflunisal, salsalate) increases the risk of GI toxicity, with little or no increase in efficacy [see Warnings and Precautions (5.2)].
Intervention: The concomitant use of Arthrotec with other NSAIDs or salicylates is not recommended.
Pemetrexed
Clinical Impact: Concomitant use of diclofenac and pemetrexed may increase the risk of pemetrexed-associated myelosuppression, renal, and GI toxicity (see the pemetrexed prescribing information).
Intervention: During concomitant use of Arthrotec and pemetrexed, in patients with renal impairment whose creatinine clearance ranges from 45 to 79 mL/min, monitor for myelosuppression, renal and GI toxicity.
NSAIDs with short elimination half-lives (e.g., diclofenac, indomethacin) should be avoided for a period of two days before, the day of, and two days following administration of pemetrexed.
In the absence of data regarding potential interaction between pemetrexed and NSAIDs with longer half-lives (e.g., meloxicam, nabumetone), patients taking these NSAIDs should interrupt dosing for at least five days before, the day of, and two days following pemetrexed administration.
Antacids
Clinical Impact: Antacids reduce the bioavailability of misoprostol acid. Antacids may also delay absorption of diclofenac. Magnesium-containing antacids exacerbate misoprostol-associated diarrhea.
Intervention: Concomitant use of Arthrotec and magnesium-containing antacids is not recommended.
Corticosteroids
Clinical Impact: Concomitant use of corticosteroids with diclofenac may increase the risk of GI ulceration or bleeding.
Intervention Monitor patients with concomitant use of Arthrotec with corticosteroids for signs of bleeding [see Warnings and Precautions (5.2)].
CYP2C9 Inhibitors or Inducers
Clinical Impact: Diclofenac is metabolized by cytochrome P450 enzymes, predominantly by CYP2C9. Co-administration of diclofenac with CYP2C9 inhibitors (e.g. voriconzaole) may enhance the exposure and toxicity of diclofenac [see Clinical Pharmacology (12.3)] whereas co-administration with CYP2C9 inducers (e.g., rifampin) may lead to compromised efficacy of diclofenac.
Intervention: CYP 2C9 inhibitors: When concomitant use of CYP2C9 inhibitors is necessary, the total daily dose of diclofenac should not exceed the lowest recommended dose of Arthrotec 50 twice daily [see Dosage and Administration (2)].
CYP2C9 inducers: A dosage adjustment may be warranted when Arthrotec is administered with CYP2C9 inducers. Administer the separate products of misoprostol and diclofenac if a higher dose of diclofenac is deemed necessary.

Overdosage

The toxic dose of Arthrotec has not been determined. However, signs of overdosage from the components of the product have been described.

Diclofenac

Symptoms following acute NSAID overdosages have been typically limited to lethargy, drowsiness, nausea, vomiting, and epigastric pain, which have been generally reversible with supportive care. Gastrointestinal bleeding has occurred. Hypertension, acute renal failure, respiratory depression, and coma have occurred, but were rare [see Warnings and Precautions (5.1, 5.2, 5.4, 5.6)].

Clinical signs that may suggest diclofenac sodium overdose include GI complaints, confusion, drowsiness, or general hypotonia.

Manage patients with symptomatic and supportive care following an NSAID overdosage. There are no specific antidotes. Consider emesis and/or activated charcoal (60 to 100 grams in adults, 1 to 2 grams per kg of body weight in pediatric patients) and/or osmotic cathartic in symptomatic patients seen within four hours of ingestion or in patients with a large overdosage (5 to 10 times the recommended dosage). Forced diuresis, alkalinization of urine, hemodialysis, or hemoperfusion may not be useful due to high protein binding.

Misoprostol

The toxic dose of misoprostol in humans has not been determined. Cumulative total daily doses of 1600 mcg have been tolerated, with only symptoms of GI discomfort being reported. Clinical signs that may indicate an overdose are sedation, tremor, convulsions, dyspnea, abdominal pain, diarrhea, fever, palpitations, hypotension, or bradycardia.

Arthrotec

Symptoms of overdosage with Arthrotec should be treated with supportive therapy. In case of acute overdosage, gastric lavage is recommended. Induced diuresis may be beneficial because diclofenac sodium and misoprostol metabolites are excreted in the urine. The effect of dialysis or hemoperfusion on the elimination of diclofenac sodium (99% protein bound) and misoprostol acid remains unproven. The use of oral activated charcoal may help to reduce the absorption of diclofenac sodium and misoprostol.

For additional information about overdosage treatment contact a poison control center (1-800-222-1222).

Arthrotec Description

Arthrotec (diclofenac sodium/misoprostol) is a combination product containing diclofenac sodium, a nonsteroidal anti-inflammatory drug (NSAID) with analgesic properties, and misoprostol, a gastrointestinal (GI) mucosal protective prostaglandin E1 analog. Arthrotec oral tablets are white to off-white, round, biconvex, and approximately 11 mm in diameter. Each tablet consists of an enteric-coated core containing 50 mg (Arthrotec 50) or 75 mg (Arthrotec 75) diclofenac sodium surrounded by an outer mantle containing 200 mcg misoprostol.

Diclofenac sodium is a phenylacetic acid derivative that is a white to off-white, virtually odorless, crystalline powder. Diclofenac sodium is freely soluble in methanol, soluble in ethanol, and practically insoluble in chloroform and in dilute acid. Diclofenac sodium is sparingly soluble in water. Its chemical formula and name are:

C14H10Cl2NO2Na [M.W. = 318.14] 2-[(2,6-dichlorophenyl) amino] benzeneacetic acid, monosodium salt.

Misoprostol is a water-soluble, viscous liquid that contains approximately equal amounts of two diastereomers. Its chemical formula and name are:

C22H38O5 [M.W. = 382.54] (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate.

Inactive ingredients in Arthrotec include: colloidal silicon dioxide; crospovidone; hydrogenated castor oil; hypromellose; lactose; magnesium stearate; methacrylic acid copolymer; microcrystalline cellulose; povidone (polyvidone) K-30; sodium hydroxide; starch (corn); talc; triethyl citrate.

Clinical Studies

Osteoarthritis

Diclofenac sodium, as a single ingredient or in combination with misoprostol, has been shown to be effective in the management of the signs and symptoms of osteoarthritis.

Rheumatoid arthritis

Diclofenac sodium, as a single ingredient or in combination with misoprostol, has been shown to be effective in the management of the signs and symptoms of rheumatoid arthritis.

Upper gastrointestinal safety

Diclofenac, and other NSAIDs, have caused serious gastrointestinal toxicity, such as bleeding, ulceration, and perforation of the stomach, small intestine or large intestine. Misoprostol has been shown to reduce the incidence of endoscopically diagnosed NSAID-induced gastric and duodenal ulcers. In a 12-week, randomized, double-blind, dose-response study, misoprostol 200 mcg administered four, three or two times a day, was significantly more effective than placebo in reducing the incidence of gastric ulcer in OA and RA patients using a variety of NSAIDs. The three times a day regimen was therapeutically equivalent to misoprostol 200 mcg four times a day with respect to the prevention of gastric ulcers. Misoprostol 200 mcg given two times a day was less effective than 200 mcg given three or four times a day. The incidence of NSAID-induced duodenal ulcer was also significantly reduced with all three regimens of misoprostol compared to placebo (see Table 3).

Table 3
Misoprostol 200 mcg Dosage Regimen
Placebo two times a day three times a day four times a day
N=1623; 12 weeks
* Misoprostol significantly different from placebo (p<0.05)
Gastric ulcer 11% 6%* 3%* 3%*
Duodenal ulcer 6% 2%* 3%* 1%*

Results of a study in 572 patients with osteoarthritis demonstrate that patients receiving Arthrotec have a lower incidence of endoscopically defined gastric ulcers compared to patients receiving diclofenac sodium (see Table 4).

Table 4
Osteoarthritis patients with history of ulcer or erosive disease (N=572), 6 weeks Incidence of ulcers
Gastric Duodenal
* Statistically significantly different from diclofenac (p<0.05)
Arthrotec 50 three times a day 3%* 6%
Arthrotec 75 two times a day 4%* 3%
diclofenac sodium 75 mg two times a day 11% 7%
Placebo 3% 1%

PRINCIPAL DISPLAY PANEL - 50 mg/200 mcg Tablet Bottle Label

ALWAYS DISPENSE WITH MEDICATION GUIDE

Pfizer

NDC 0025-1411-60

Arthrotec® 50
(50 mg diclofenac sodium/
200 mcg misoprostol) tablets

50 mg/200 mcg

DOSAGE AND USE
See accompanying prescribing information.

60 Tablets
Rx only

20686828

PRINCIPAL DISPLAY PANEL - 50 mg Carton

ALWAYS DISPENSE WITH MEDICATION GUIDE
NDC 0025-1411-34
100 Tablets
UNIT DOSE

2146
MADE IN ENGLAND

Arthrotec® 50
50 mg diclofenac sodium/
200 mcg misoprostol

50 mg/200 mcg

11004701

PRINCIPAL DISPLAY PANEL - 75 mg/200 mcg Tablet Bottle Label

ALWAYS DISPENSE WITH MEDICATION GUIDE

Pfizer

NDC 0025-1421-60

Arthrotec® 75
(75 mg diclofenac sodium/
200 mcg misoprostol) tablets

75 mg/200 mcg

DOSAGE AND USE
See accompanying prescribing information.

60 Tablets
Rx only

20686830

Arthrotec side effects

Get emergency medical help if you have signs of an allergic reaction to Arthrotec: sneezing, runny or stuffy nose; wheezing or trouble breathing; hives; swelling of your face, lips, tongue, or throat.

Get emergency medical help if you have signs of a heart attack or stroke: chest pain spreading to your jaw or shoulder, sudden numbness or weakness on one side of the body, slurred speech, feeling short of breath.

Stop using Arthrotec and call your doctor at once if you have:

  • the first sign of any skin rash, no matter how mild;

  • shortness of breath (even with mild exertion);

  • swelling or rapid weight gain;

  • signs of stomach bleeding - bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;

  • liver problems - nausea, upper stomach pain, itching, tired feeling, flu-like symptoms, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

  • kidney problems - little or no urinating, painful or difficult urination, swelling in your feet or ankles, feeling tired or short of breath;

  • low red blood cells (anemia) - pale skin, feeling light-headed or short of breath, rapid heart rate, trouble concentrating; or

  • severe skin reaction - fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Common Arthrotec side effects may include:

  • abnormal vaginal bleeding;

  • heartburn, indigestion stomach pain, gas;

  • nausea, vomiting;

  • diarrhea, constipation; or

  • dizziness.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

(web3)