Indications and Usage
Carefully consider the potential benefits and risks of piroxicam capsules and other treatment options before deciding to use piroxicam capsules. Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals (see WARNINGS).
Piroxicam capsules are indicated:
- For relief of the signs and symptoms of osteoarthritis.
- For relief of the signs and symptoms of rheumatoid arthritis.
Dosage and Administration
Carefully consider the potential benefits and risks of piroxicam capsules and other treatment options before deciding to use piroxicam 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 piroxicam capsules, the dose and frequency should be adjusted to suit an individual patient's needs.
For the relief of rheumatoid arthritis and osteoarthritis, the recommended dose is 20 mg given orally once per day. If desired, the daily dose may be divided. Because of the long half-life of piroxicam capsules, steady-state blood levels are not reached for 7 to 12 days. Therefore, although the therapeutic effects of piroxicam are evident early in treatment, there is a progressive increase in response over several weeks and the effect of therapy should not be assessed for two weeks.
Contraindications
Piroxicam capsules are contraindicated in patients with known hypersensitivity to piroxicam.
Piroxicam 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).
Piroxicam capsules are contraindicated for the treatment of peri-operative pain in the setting of coronary artery bypass graft (CABG) surgery (see WARNINGS).
Adverse Reactions
In patients taking piroxicam capsules or other NSAIDs, the most frequently reported adverse experiences occurring in approximately 1 to 10% of patients are:
Cardiovascular System: Edema.
Digestive System: Anorexia, abdominal pain, constipation, diarrhea, dyspepsia, elevated liver enzymes, flatulence, gross bleeding/perforation, heartburn, nausea, ulcers (gastric/duodenal), vomiting.
Hemic and Lymphatic System: Anemia, increased bleeding time.
Nervous System: Dizziness, headache.
Skin and Appendages: Pruritus, rash.
Special Senses: Tinnitus.
Urogenital System: Abnormal renal function.
Additional adverse experiences reported occasionally include:
Body As a Whole: Fever, infection, sepsis.
Cardiovascular System: Congestive heart failure, hypertension, tachycardia, syncope.
Digestive System: Dry mouth, esophagitis, gastritis, glossitis, hematemesis, hepatitis, jaundice, melena, rectal bleeding, stomatitis.
Hemic and Lymphatic System: Ecchymosis, eosinophilia, epistaxis, leukopenia, purpura, petechial rash, thrombocytopenia.
Metabolic and Nutritional: Weight changes.
Nervous System: Anxiety, asthenia, confusion, depression, dream abnormalities, drowsiness, insomnia, malaise, nervousness, paresthesia, somnolence, tremors, vertigo.
Respiratory System: Asthma, dyspnea.
Skin and Appendages: Alopecia, bruising, desquamation, erythema, photosensitivity, sweat.
Special Senses: Blurred vision.
Urogenital System: Cystitis, dysuria, hematuria, hyperkalemia, interstitial nephritis, nephrotic syndrome, oliguria/polyuria, proteinuria, renal failure.
Other adverse reactions which occur rarely are:
Body As a Whole: Anaphylactic reactions, appetite changes, death, flu-like syndrome, pain (colic), serum sickness.
Cardiovascular System: Arrhythmia, exacerbation of angina, hypotension, myocardial infarction, palpitations, vasculitis.
Digestive System: Eructation, liver failure, pancreatitis.
Hemic and Lymphatic System: Agranulocytosis, hemolytic anemia, aplastic anemia, lymphadenopathy, pancytopenia.
Hypersensitivity: Positive ANA.
Metabolic and Nutritional: Hyperglycemia, hypoglycemia.
Nervous System: Akathisia, convulsions, coma, hallucinations, meningitis, mood alterations.
Respiratory: Respiratory depression, pneumonia.
Skin and Appendages: Angioedema, toxic epidermal necrosis, erythema multiforme, exfoliative dermatitis, onycholysis, Stevens-Johnson syndrome, urticaria, vesiculobullous reaction.
Special Senses: Conjunctivitis, hearing impairment, swollen eyes.
Drug Interactions
Highly Protein Bound Drugs
Piroxicam is highly protein bound and, therefore, might be expected to displace other protein bound drugs. Physicians should closely monitor patients for a change in dosage requirements when administering piroxicam capsules to patients on other highly protein bound drugs.
Aspirin
When piroxicam is administered with aspirin, its protein binding is reduced, although the clearance of free piroxicam is not altered. Plasma levels of piroxicam are depressed to approximately 80% of their normal values when piroxicam is administered (20 mg/day) in conjunction with aspirin (3900 mg/day). The clinical significance of this interaction is not known; however, as with other NSAIDs, concomitant administration of piroxicam capsules and aspirin is not generally recommended because of the potential for increased adverse effects.
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.
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.
Diuretics
Clinical studies, as well as postmarketing observations, have shown that piroxicam capsules 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 WARNINGS, 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.
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.
Use in Specific Populations
Pediatric
Piroxicam capsules have not been investigated in pediatric patients.
Race
Pharmacokinetic differences due to race have not been identified.
Hepatic Insufficiency
The effects of hepatic disease on piroxicam pharmacokinetics have not been established. However, a substantial portion of piroxicam elimination occurs by hepatic metabolism. Consequently, patients with hepatic disease may require reduced doses of piroxicam as compared to patients with normal hepatic function.
Renal Insufficiency
Piroxicam pharmacokinetics have been investigated in patients with renal insufficiency. Studies indicate patients with mild to moderate renal impairment may not require dosing adjustments. However, the pharmacokinetic properties of piroxicam in patients with severe renal insufficiency or those receiving hemodialysis are not known.
Overdosage
Symptoms following acute NSAID overdoses are usually limited to lethargy, drowsiness, nausea, vomiting, and epigastric pain, which are generally reversible with supportive care. Gastrointestinal bleeding can occur. Hypertension, acute renal failure, respiratory depression, and coma may occur, but are rare. Anaphylactoid reactions have been reported with therapeutic ingestion of NSAIDs, and may occur following an overdose.
Patients should be managed by symptomatic and supportive care following an NSAID overdose. There are no specific antidotes. Emesis and/or activated charcoal (60 to 100 g in adults, 1 to 2 g/kg in children) and/or osmotic cathartic may be indicated. The long plasma half-life of piroxicam should be considered when treating an overdose with piroxicam. Experiments in dogs have demonstrated that the use of multiple-dose treatments with activated charcoal could reduce the half-life of piroxicam by more than 50% and systemic bioavailability by as much as 37% when activated charcoal is given as late as 6 hours after ingestion of piroxicam. Forced diuresis, alkalinization of urine, hemodialysis, or hemoperfusion may not be useful due to high protein binding.
Description
Piroxicam capsules contain piroxicam which is a member of the oxicam group of non-steroidal anti-inflammatory drugs (NSAIDs). Each dark green capsule contains 20 mg piroxicam for oral administration. The chemical name for piroxicam is 4-hydroxy-2-methyl-N-2-pyridinyl-2H-1,2-benzothiazine-3- carboxamide 1,1-dioxide. Members of the oxicam family are not carboxylic acids, but they are acidic by virtue of the enolic 4-hydroxy substituent. Piroxicam occurs as a white crystalline solid, sparingly soluble in water, dilute acid and most organic solvents. It is slightly soluble in alcohol and in aqueous alkaline solutions. It exhibits a weakly acidic 4-hydroxy proton (pKa 5.1) and a weakly basic pyridyl nitrogen (pKa 1.8). It has the following structural formula:
C15H13N3O4S M.W. 331.35
Each capsule, for oral administration, 20 mg piroxicam. In addition, each capsule contains the following inactive ingredients: colloidal silicon dioxide, corn starch, D&C Yellow No. 10, FD&C Green No. 3, gelatin, lactose, magnesium stearate, povidone, sodium lauryl sulfate, and titanium dioxide.
piroxicam capsuleClinical Pharmacology
Pharmacodynamics
Piroxicam capsules are a non-steroidal anti-inflammatory drug (NSAID) that exhibits anti-inflammatory, analgesic, and antipyretic activities in animal models. The mechanism of action of piroxicam, like that of other NSAIDs, is not completely understood but may be related to prostaglandin synthetase inhibition.
Pharmacokinetics
Absorption
Piroxicam is well absorbed following oral administration. Drug plasma concentrations are proportional for 10 and 20 mg doses and generally peak within three to five hours after medication. The prolonged half-life (50 hours) results in the maintenance of relatively stable plasma concentrations throughout the day on once daily doses and to significant accumulation upon multiple dosing. A single 20 mg dose generally produces peak piroxicam plasma levels of 1.5 to 2 mcg/mL, while maximum drug plasma concentrations, after repeated daily ingestion of 20 mg piroxicam capsules, usually stabilize at 3 to 8 mcg/mL. Most patients approximate steady- state plasma levels within 7 to 12 days. Higher levels, which approximate steady state at two to three weeks, have been observed in patients in whom longer plasma half-lives of piroxicam occurred.
With food there is a slight delay in the rate but not the extent of absorption following oral administration. The concomitant administration of antacids (aluminum hydroxide or aluminum hydroxide with magnesium hydroxide) have been shown to have no effect on the plasma levels of orally administered piroxicam.
Distribution
The apparent volume of distribution of piroxicam is approximately 0.14 L/kg. Ninety-nine percent of plasma piroxicam is bound to plasma proteins. Piroxicam is excreted into human milk. The presence in breast milk has been determined during initial and long-term conditions (52 days). Piroxicam appeared in breast milk at about 1% to 3% of the maternal concentration. No accumulation of piroxicam occurred in milk relative to that in plasma during treatment.
Metabolism
Metabolism of piroxicam occurs by hydroxylation at the 5 position of the pyridyl side chain and conjugation of this product; by cyclodehydration; and by a sequence of reactions involving hydrolysis of the amide linkage, decarboxylation, ring contraction and N-demethylation. The biotransformation products of piroxicam metabolism are reported to not have any anti-inflammatory activity.
Excretion
Piroxicam and its biotransformation products are excreted in urine and feces, with about twice as much appearing in the urine as in the feces. Approximately 5% of a piroxicam dose is excreted unchanged. The plasma half-life (T½) for piroxicam is approximately 50 hours.
Special Populations
Pediatric
Piroxicam capsules have not been investigated in pediatric patients.
Race
Pharmacokinetic differences due to race have not been identified.
Hepatic Insufficiency
The effects of hepatic disease on piroxicam pharmacokinetics have not been established. However, a substantial portion of piroxicam elimination occurs by hepatic metabolism. Consequently, patients with hepatic disease may require reduced doses of piroxicam as compared to patients with normal hepatic function.
Renal Insufficiency
Piroxicam pharmacokinetics have been investigated in patients with renal insufficiency. Studies indicate patients with mild to moderate renal impairment may not require dosing adjustments. However, the pharmacokinetic properties of piroxicam in patients with severe renal insufficiency or those receiving hemodialysis are not known.
Other Information
In controlled clinical trials, the effectiveness of piroxicam has been established for both acute exacerbations and long-term management of rheumatoid arthritis and osteoarthritis.
The therapeutic effects of piroxicam are evident early in the treatment of both diseases with a progressive increase in response over several (8 to 12) weeks. Efficacy is seen in terms of pain relief and, when present, subsidence of inflammation.
Doses of 20 mg/day piroxicam display a therapeutic effect comparable to therapeutic doses of aspirin, with a lower incidence of minor gastrointestinal effects and tinnitus.
Piroxicam has been administered concomitantly with fixed doses of gold and corticosteroids. The existence of a “steroid-sparing” effect has not been adequately studied to date.
How Supplied / Storage and Handling
Piroxicam capsules USP, 20 mg are a #2 capsule with a dark green cap and a dark green body imprinted "93" "756" on the cap and body. They are available in bottles of 15.
Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature].
Dispense in a tight, light-resistant container as defined in the USP with a child-resistant closure (as required).
Manufactured for:
Keltman Pharmaceuticals Inc.
1 Lakeland Square, Suite A
Flowood, Ms 39232
R4
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.
- Piroxicam capsules, like other NSAIDs, may cause serious CV side effects, such as MI or stroke, which may result in hospitalization and even death. Although serious CV events can occur without warning symptoms, patients should be alert for the signs and symptoms of chest pain, shortness of breath, weakness, slurring of speech, and should ask for medical advice when observing any indicative signs or symptoms. Patients should be apprised of the importance of this follow-up (see WARNINGS, Cardiovascular Effects).
- Piroxicam capsules, 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 signs 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).
- Piroxicam capsules, like other NSAIDs, can cause serious skin side effects such as exfoliative dermatitis, SJS and TEN, which may result in hospitalization and even death. Although serious skin reactions may occur without warning, patients should be alert for the signs and symptoms of skin rash and blisters, fever, or other signs of hypersensitivity such as itching, and should ask for medical advice when observing any indicative signs or symptoms. Patients should be advised to stop the drug immediately if they develop any type of rash and contact their physicians as soon as possible.
- Patients should promptly report signs or symptoms of unexplained weight gain, or edema to their physicians.
- 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.
- 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).
- In late pregnancy, as with other NSAIDs, piroxicam capsules should be avoided because they may cause premature closure of the ductus arteriosus.