Professional Information — Meclofenamate Sodium

Indications and Usage

Carefully consider the potential benefits and risks of meclofenamate sodium capsules and other treatment options before deciding to use meclofenamate sodium capsules. Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals (see WARNINGS).

Meclofenamate sodium capsules are indicated:

• For reduction of fever in adults
• For relief of mild to moderate pain in adults
• For relief of signs and symptoms of juvenile arthritis.
• For relief of the signs and symptoms of rheumatoid arthritis
• For relief of the signs and symptoms of osteoarthritis.
• For treatment of primary dysmenorrhea.
• For acute or long-term use in the relief of signs and symptoms of the following: 1.Ankylosing spondylitis 2.Acute painful shoulder (Acute subacromial bursitis/supraspinatus tendinitis) 3.Acute gouty arthritis

Meclofenamate sodium capsules are also indicated for the treatment of idiopathic heavy menstrual blood loss (see CLINICAL PHARMACOLOGY and PRECAUTIONS).

As with all nonsteroidal anti-inflammatory drugs, selection of meclofenamate sodium capsules require a careful assessment of the benefit/risk ratio (see WARNINGS, PRECAUTIONS and ADVERSE REACTIONS).

Meclofenamate sodium capsules are not recommended in children because adequate studies to demonstrate safety and efficacy have not been carried out.

Dosage and Administration

Carefully consider the potential benefits and risks of meclofenamate sodium capsules and other treatment options before deciding to use meclofenamate sodium capsules. Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals (see WARNINGS).

After observing the response to initial therapy with meclofenamate sodium capsules, the dose and frequency should be adjusted to suit an individual patient's needs.

Usual Dosage

For Mild to Moderate Pain

The recommended dose is 50 mg every 4 to 6 hours. Doses of 100 mg may be needed in some patients for optimal pain relief (see CLINICAL PHARMACOLOGY). However, the daily dose should not exceed 400 mg (see ADVERSE REACTIONS).

For excessive menstrual blood loss and primary dysmenorrheal

The recommended dose of meclofenamate sodium is 100 mg 3 times a day, for up to 6 days, starting at the onset of menstrual flow.

For rheumatoid arthritis and osteoarthritis (including acute exacerbations of chronic disease)

The dosage is 200 mg to 400 mg per day, administered in three or four equal doses.

Therapy should be initiated at the lower dosage, then increased as necessary to improve clinical response. The dosage should be individually adjusted for each patient, depending on the severity of the symptoms and the clinical response. The daily dosage should not exceed 400 mg per day. The smallest dosage of meclofenamate sodium that yields clinical control should be employed.

Although improvement may be seen in some patients in a few days, 2 to 3 weeks of treatment may be required to obtain the optimum therapeutic benefit.

After a satisfactory response has been achieved, the dosage should be adjusted as required. A lower dosage may suffice for long-term administration.

If gastrointestinal complaints occur (see WARNINGS and PRECAUTIONS), meclofenamate sodium may be administered with meals or with milk (see CLINICAL PHARMACOLOGY for a description of food effects). If intolerance occurs, the dosage may need to be reduced. Therapy should be terminated if any severe adverse reactions occur.

Contraindications

Meclofenamate sodium capsules are contraindicated in patients with known hypersensitivity to meclofenamate sodium.

Meclofenamate sodium capsules should not be given to patients who have experienced asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs. Severe, rarely fatal, anaphylactic-like reactions to NSAIDs have been reported in such patients (see WARNINGS: Anaphylactoid Reactions and PRECAUTIONS: Preexisting Asthma).

Meclofenamate sodium capsules are contraindicated in the setting of coronary artery bypass graft (CABG) surgery (see WARNINGS).

Adverse Reactions

Incidence Greater Than 1%

The following adverse reactions were observed in clinical trials and included observations from more than 2,700 patients, 594 of whom were treated for one year and 248 for at least 2 years.

Gastrointestinal

The most frequently reported adverse reactions associated with meclofenamate sodium involve the gastrointestinal system. In controlled studies of up to 6 months duration, these disturbances occurred in the following decreasing order of frequency with the approximate incidences in parentheses: diarrhea (10% to 33%), nausea with or without vomiting (11%), other gastrointestinal disorders (10%), and abdominal pain^*. In long-term uncontrolled studies of up to 4 years duration, one third of the patients had at least one episode of diarrhea some time during meclofenamate sodium therapy.

In approximately 4% of the patients in controlled studies, diarrhea was severe enough to require discontinuation of meclofenamate sodium. The occurrence of diarrhea is dose related, generally subsides with dose reduction, and clears with termination of therapy. The incidence of diarrhea in patients with osteoarthritis is generally lower than that reported in patients with rheumatoid arthritis.

Other reactions less frequently reported were pyrosis^*, flatulence^*, anorexia, constipation, stomatitis, and peptic ulcer. The majority of the patients with peptic ulcer had either a history of ulcer disease or were receiving concomitant anti-inflammatory drugs, including corticosteroids which are known to produce peptic ulceration.

Cardiovascular:  edema

Dermatologic:  rash^*, urticaria, pruritus

Central Nervous System:  headache^*, dizziness^*

Special Senses:  tinnitus

^* Incidence between 3% and 9%. Those reactions occurring in 1% to 3% of patients are not marked with an asterisk.

Incidence Less Than 1%—Probably Causally Related

The following adverse reactions were reported less frequently than 1% during controlled clinical trials and through voluntary reports since marketing. The probability of a causal relationship exists between the drug and these adverse reactions.

Gastrointestinal:  bleeding and/or perforation with or without obvious ulcer formation, colitis, cholestatic jaundice

Renal:  renal failure

Hematologic:  neutropenia, thrombocytopenic purpura, leukopenia, agranulocytosis, hemolytic anemia, eosinophilia, decrease in hemoglobin and/or hematocrit

Dermatologic:  erythema multiforme, Stevens-Johnson Syndrome, exfoliative dermatitis, toxic epidermal necrolysis (TEN), and fixed drug eruption (FDE)

Hepatic:  alteration of liver function tests

Allergic:  lupus and serum sickness-like symptoms

Incidence Less Than 1%—Causal Relationship Unknown

Other reactions have been reported but under conditions where a causal relationship could not be established. However, in these rarely reported events, that possibility cannot be excluded. Therefore, these observations are listed to alert physicians.

Cardiovascular:  palpitations

Central Nervous System:  malaise, fatigue, paresthesia, insomnia, depression

Special Senses:  blurred vision, taste disturbances, decreased visual acuity, temporary loss of vision, reversible loss of color vision, retinal changes including macular fibrosis, macular and perimacular edema, conjunctivitis, iritis

Renal:  nocturia

Gastrointestinal:  paralytic ileus

Dermatologic:  erythema nodosum, hair loss

Drug Interactions

ACE-inhibitors

Reports suggest that NSAIDs may diminish the antihypertensive effect of ACE-inhibitors. This interaction should be given consideration in patients taking NSAIDs concomitantly with ACE-inhibitors.

Aspirin

When meclofenamate sodium in administered with aspirin, its protein binding is reduced, although the clearance of free meclofenamate sodium is not altered. The clinical significance of this interaction is not known; however, as with other NSAIDs, concomitant administration of meclofenamate sodium capsules and aspirin is not generally recommended because of the potential of increased adverse effects.

Furosemide

Clinical studies, as well as post-marketing observations, have shown that meclofenamate sodium can reduce the natriuretic effect-of furosemide and thiazides in some patients. This response has been attributed to inhibition of renal prostaglandin synthesis. During concomitant therapy with NSAIDs, the patient should be observed closely for signs of renal failure (see PRECAUTIONS: Renal Effects), as well as to assure diuretic efficacy.

Lithium

NSAIDs have produced an elevation of plasma lithium levels and a reduction in renal lithium clearance. The mean minimum lithium concentration increased 15% and the renal clearance was decreased by approximately 20%. These effects have been attributed to inhibition of renal prostaglandin synthesis by the NSAID. Thus, when NSAIDs and lithium are administered concurrently, subjects should be observed carefully for signs of lithium toxicity.

Methotrexate

NSAIDs have been reported to competitively inhibit methotrexate accumulation in rabbit kidney slices. This may indicate that they could enhance the toxicity of methotrexate. Caution should be used when NSAIDs are administered concomitantly with methotrexate.

Warfarin

The effects of warfarin and NSAIDs on GI bleeding are synergistic, such that users of both drugs together have a risk of serious GI bleeding higher than users of either drug alone.

Overdosage

The following is based on the little information available concerning overdosage with meclofenamate sodium and related compounds. After a massive overdose, CNS stimulation may be manifested by irrational behavior, marked agitation and generalized seizures. Following this phase, renal toxicity (falling urine output, rising creatinine, abnormal urinary cellular elements) may be noted with possible oliguria or anuria and azotemia. A 24 year-old male was anuric for approximately one week after ingesting an overdose of 6 to 7 grams of meclofenamate sodium. Spontaneous diuresis and recovery subsequently occurred.

Management consists of emptying the stomach by emesis or lavage and instilling an ample dose of activated charcoal into the stomach. There is some evidence that charcoal will actively absorb meclofenamate sodium, but dialysis or hemoperfusion may be less effective because of plasma protein binding. The seizures should be controlled by an appropriate anticonvulsant regimen. Attention should be directed throughout, by careful monitoring, to the preservation of vital functions and fluid-electrolyte balance. Dialysis may be required to correct serious azotemia or electrolyte imbalance.

Description

Meclofenamate sodium is N-(2,6-dichloro-m-tolyl) anthranilic acid, sodium salt, monohydrate. It is an anti-inflammatory drug for oral administration. Meclofenamate sodium capsules, USP contain 50 mg or 100 mg meclofenamic acid as the sodium salt and the following inactive ingredients: colloidal silicon dioxide, D&C Yellow No. 10, FD&C Blue No. 1, FD&C Red No. 3, gelatin, magnesium stearate, microcrystalline cellulose, pregelatinized starch (corn), sodium lauryl sulfate and titanium dioxide.

In addition, the imprinting ink contains black iron oxide, D&C Yellow No. 10 Aluminum Lake, FD&C Blue No. 1 Aluminum Lake, FD&C Blue No. 2 Aluminum Lake, FD&C Red No. 40 Aluminum Lake, propylene glycol and shellac glaze.

The structural formula of meclofenamate sodium is:

It is a white to creamy white, odorless to almost odorless, crystalline powder with melting point 287° to 291°C, molecular weight 336.15, and it is freely soluble in water.

Clinical Pharmacology

Pharmacodynamics

Meclofenamate sodium is a nonsteroidal agent which has demonstrated anti-inflammatory, analgesic, and antipyretic activity in laboratory animals. The mode of action, like that of other nonsteroidal anti-inflammatory agents, is not known. Therapeutic action does not result from pituitary-adrenal stimulation. In animal studies, meclofenamate sodium was found to inhibit prostaglandin synthesis and to compete for binding at the prostaglandin receptor site. In vitro, meclofenamate sodium was found to be an inhibitor of human leukocyte 5-lipoxygenase activity. These properties may be responsible for the anti-inflammatory action of meclofenamate sodium. There is no evidence that meclofenamate sodium alters the course of the underlying disease.

In several human isotope studies, meclofenamate sodium, at a dosage of 300 mg/day, produced a fecal blood loss of 1 to 2 mL per day, and 2 to 3 mL per day at 400 mg/day. Aspirin, at a dosage of 3.6 g/day, caused a fecal blood loss of 6 mL per day.

In a multiple-dose, 1-week study in normal human volunteers, meclofenamate sodium had little or no effect on collagen-induced platelet aggregation, platelet count, or bleeding time. In comparison, aspirin suppressed collagen-induced platelet aggregation and increased bleeding time. The concomitant administration of antacids (aluminum and magnesium hydroxides) does not interfere with absorption of meclofenamate sodium.

Pharmacokinetics

Meclofenamate sodium is rapidly absorbed in man following single and multiple oral doses with peak plasma concentrations occurring in 0.5 to 2 hours. Based on a comparison to a suspension of meclofenamic acid, meclofenamate sodium is completely bioavailable.

The plasma concentrations of meclofenamic acid decline monoexponentially following oral administration. In a study in ten healthy subjects following a single oral dose the apparent elimination half-life ranged from 0.8 to 5.3 hours. After the administration of meclofenamate sodium for 14 days every 8 hours, the apparent elimination half-life ranged from 0.8 to 2.1 hours with no evidence of accumulation of meclofenamic acid in plasma (see Table).

Meclofenamic acid is extensively metabolized to an active metabolite (Metabolite I; 3-hydroxymethyl metabolite of meclofenamic acid) and at least six other less well characterized minor metabolites. Only this Metabolite I has been shown in vitro to inhibit cyclooxygenase activity with approximately one fifth the activity of meclofenamate sodium. Metabolite I (3-hydroxymethyl metabolite of meclofenamic acid) with a mean half-life of approximately 15 hours did accumulate following multiple dosing. After the administration of 100 mg meclofenamate sodium for 14 days every 8 hours, Metabolite I reached a peak plasma concentration of only 1 mcg/mL. By contrast, the peak concentration was 4.8 mcg/mL for the parent compound on both days 1 and 14. Therefore, the accumulation of Metabolite I is probably not clinically significant.

Approximately 70% of the administered dose is excreted by the kidneys with 8% to 35% excreted as predominantly conjugated species of meclofenamic acid and Metabolite I (see Table). Other metabolites, whose excretion rates are unknown, account for the remaining 35% to 62% of the dose excreted in the urine. The remainder of the administered dose (approximately 30%) is eliminated in the feces (apparently through biliary excretion). There is insufficient experience to know if meclofenamate sodium or its metabolites accumulate in patients with compromised renal or hepatic function. Therefore, meclofenamate sodium should be used with caution in these patients (see PRECAUTIONS). Trace amounts of meclofenamate sodium are excreted in human breast milk.

Meclofenamic acid is greater than 99% bound to plasma proteins over a wide drug concentration range.

Unlike most NSAIDs, which when administered with food have a decrease in rate but not in extent of absorption, meclofenamic acid is decreased in both. It has been reported that following the administration of meclofenamate sodium capsules one-half hour after a meal, the average extent of bioavailability decreased by 26%, the average peak concentration (C_max) decreased 4-fold and the time to C_max was delayed by 3 hours.

Clinical Studies

Controlled clinical trials comparing meclofenamate sodium with aspirin demonstrated comparable efficacy in rheumatoid arthritis.

The meclofenamate sodium treated patients had fewer reactions involving the special senses, specifically tinnitus, but more gastrointestinal reactions, specifically diarrhea.

The incidence of patients who discontinued therapy due to adverse reactions was similar for both the meclofenamate sodium and aspirin-treated groups.

The improvement with meclofenamate sodium reported by patients and the reduction of the disease activity as evaluated by both physicians and patients with rheumatoid arthritis are associated with a significant reduction in number of tender joints, severity of tenderness, and duration of morning stiffness.

The improvement reported by patients and as evaluated by physicians in patients treated with meclofenamate sodium for osteoarthritis is associated with a significant reduction in night pain, pain on walking, degree of starting pain, and pain on passive motion. The function of knee joints also improved significantly.

Meclofenamate sodium has been used in combination with gold salts or corticosteroids in patients with rheumatoid arthritis. Studies have demonstrated that meclofenamate sodium contributes to the improvement of patients’ conditions while maintained on gold salts or corticosteroids. Data are inadequate to demonstrate that meclofenamate sodium in combination with salicylates produces greater improvement than that achieved with meclofenamate sodium alone.

In controlled clinical trials of patients with mild to moderate pain, meclofenamate sodium 50 mg provided significant pain relief. In these studies of episiotomy and dental pain, meclofenamate sodium 100 mg demonstrated additional benefit in some patients. The onset of analgesic effect was generally within one hour and the duration of action was 4 to 6 hours.

In controlled clinical trials of patients with dysmenorrhea, meclofenamate sodium 100 mg t.i.d. provided significant reduction in the symptoms associated with dysmenorrhea.

In randomized double-blind crossover trials of meclofenamate sodium 100 mg t.i.d. versus placebo in women with heavy menstrual blood loss (MBL), meclofenamate sodium treatment was usually associated with a reduction in menstrual flow.

The graph below is a scatter plot of menstrual flow from the average of two menstrual periods on meclofenamate sodium treatments (vertical axis) versus two menstrual periods on placebo (horizontal axis) for 55 women. Of note, although the amount of reduction in MBL was variable, some degree of reduction occurred in 90% of women in this study.

The points on the graph represent the mean MBL for each subject when treated for two periods with placebo and two periods with meclofenamate sodium. To ease in interpretation, the following examples may be helpful. Point A represents a woman who had MBL of 459 mL while on placebo, and 405 mL on meclofenamate sodium. Point B represents a woman who had MBL of 472 mL while on placebo, and 64 mL when treated with meclofenamate sodium.

In association with this reduction in menstrual blood loss, the duration of menses was decreased by one day; tampon/pad usage was decreased by an average of two per day on the 2 days of heaviest flow; and symptoms of dysmenorrhea were significantly reduced.

Clinical Studies

Controlled clinical trials comparing meclofenamate sodium with aspirin demonstrated comparable efficacy in rheumatoid arthritis.

The meclofenamate sodium treated patients had fewer reactions involving the special senses, specifically tinnitus, but more gastrointestinal reactions, specifically diarrhea.

The incidence of patients who discontinued therapy due to adverse reactions was similar for both the meclofenamate sodium and aspirin-treated groups.

The improvement with meclofenamate sodium reported by patients and the reduction of the disease activity as evaluated by both physicians and patients with rheumatoid arthritis are associated with a significant reduction in number of tender joints, severity of tenderness, and duration of morning stiffness.

The improvement reported by patients and as evaluated by physicians in patients treated with meclofenamate sodium for osteoarthritis is associated with a significant reduction in night pain, pain on walking, degree of starting pain, and pain on passive motion. The function of knee joints also improved significantly.

Meclofenamate sodium has been used in combination with gold salts or corticosteroids in patients with rheumatoid arthritis. Studies have demonstrated that meclofenamate sodium contributes to the improvement of patients’ conditions while maintained on gold salts or corticosteroids. Data are inadequate to demonstrate that meclofenamate sodium in combination with salicylates produces greater improvement than that achieved with meclofenamate sodium alone.

In controlled clinical trials of patients with mild to moderate pain, meclofenamate sodium 50 mg provided significant pain relief. In these studies of episiotomy and dental pain, meclofenamate sodium 100 mg demonstrated additional benefit in some patients. The onset of analgesic effect was generally within one hour and the duration of action was 4 to 6 hours.

In controlled clinical trials of patients with dysmenorrhea, meclofenamate sodium 100 mg t.i.d. provided significant reduction in the symptoms associated with dysmenorrhea.

In randomized double-blind crossover trials of meclofenamate sodium 100 mg t.i.d. versus placebo in women with heavy menstrual blood loss (MBL), meclofenamate sodium treatment was usually associated with a reduction in menstrual flow.

The graph below is a scatter plot of menstrual flow from the average of two menstrual periods on meclofenamate sodium treatments (vertical axis) versus two menstrual periods on placebo (horizontal axis) for 55 women. Of note, although the amount of reduction in MBL was variable, some degree of reduction occurred in 90% of women in this study.

The points on the graph represent the mean MBL for each subject when treated for two periods with placebo and two periods with meclofenamate sodium. To ease in interpretation, the following examples may be helpful. Point A represents a woman who had MBL of 459 mL while on placebo, and 405 mL on meclofenamate sodium. Point B represents a woman who had MBL of 472 mL while on placebo, and 64 mL when treated with meclofenamate sodium.

In association with this reduction in menstrual blood loss, the duration of menses was decreased by one day; tampon/pad usage was decreased by an average of two per day on the 2 days of heaviest flow; and symptoms of dysmenorrhea were significantly reduced.

How Supplied / Storage and Handling

Meclofenamate Sodium Capsules, USP are available containing either 50 mg or 100 mg of meclofenamic acid as the sodium salt.

The 50 mg capsules are hard-shell gelatin capsules with a coral opaque cap and a coral opaque body filled with an off-white powder blend. The capsules are axially printed with MYLAN over 2150 in black ink on both the cap and body. They are available as follows:

NDC 0378-2150-01
bottles of 100 capsules

The 100 mg capsules are hard-shell gelatin capsules with a coral opaque cap and a white opaque body filled with an off-white powder blend. The capsules are axially printed with MYLAN over 3000 in black ink on both the cap and body. They are available as follows:

NDC 0378-3000-01
bottles of 100 capsules

Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature.]

Protect from light and moisture.

Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure.

PHARMACIST: Dispense a Medication Guide with each prescription.

Patient Counseling Information

Patients should be informed of the following information before initiating therapy with an NSAID and periodically during the course of ongoing therapy. Patients should also be encouraged to read the NSAID Medication Guide that accompanies each prescription dispensed.

1. 1. Cardiovascular Thrombotic Events:  Advise patients to be alert for the symptoms of cardiovascular thrombotic events, including chest pain, shortness of breath, weakness, or slurring of speech, and to report any of these symptoms to their healthcare provider immediately (see WARNINGS).
2. 2.Meclofenamate sodium, like other NSAIDs, can cause GI discomfort and, rarely, serious GI side effects, such as ulcers and bleeding, which may result in hospitalization and even death. Although serious GI tract ulcerations and bleeding can occur without warning symptoms, patients should be alert for the signs and symptoms of ulcerations and bleeding, and should ask for medical advice when observing any indicative sign or symptoms including epigastric pain, dyspepsia, melena, and hematemesis. Patients should be apprised of the importance of this follow-up (see WARNINGS: Gastrointestinal Effects: Risk of Ulceration, Bleeding, and Perforation ).
3. 3. Serious Skin Reactions, including DRESS: Advise patients to stop taking meclofenamate sodium capsules immediately if they develop any type of rash or fever and to contact their healthcare provider as soon as possible (see WARNINGS).
4. 4. Heart Failure and Edema: Advise patients to be alert for the symptoms of congestive heart failure including shortness of breath, unexplained weight gain, or edema and to contact their healthcare provider if such symptoms occur (see WARNINGS).
5. 5.Patients should be informed of the warning signs and symptoms of hepatotoxicity (e.g., nausea, fatigue, lethargy, pruritus, jaundice, right upper quadrant tenderness, and “flu-like” symptoms). If these occur, patients should be instructed to stop therapy and seek immediate medical therapy.
6. 6.Patients should be informed of the signs of an anaphylactoid reaction (e.g., difficulty breathing, swelling of the face or throat). If these occur, patients should be instructed to seek immediate emergency help (see WARNINGS).
7. 7. Fetal Toxicity:  Inform pregnant women to avoid use of meclofenamate sodium capsules and other NSAIDs starting at 30 weeks gestation because of the risk of the premature closing of the fetal ductus arteriosus. If treatment with meclofenamate sodium capsules is needed for a pregnant woman between about 20 to 30 weeks gestation, advise her that she may need to be monitored for oligohydramnios, if treatment continues for longer than 48 hours (see WARNINGS: Fetal Toxicity, PRECAUTIONS: Pregnancy).