Overdose is unlikely to occur with this topical preparation.
Piroxiferum Gel should not be used in those patients who have previously shown hypersensitivity to Piroxiferum in any of its forms, or any of the other ingredients. The potential exists for cross sensitivity to aspirin and other non-steroidal anti-inflammatory agents.
Piroxiferum Gel should not be given to patients in whom aspirin and other non-steroidal anti-inflammatory agents induce the symptoms of asthma, nasal polyps, angioneurotic oedema or urticaria.
The metabolism of Piroxiferum is inhibited by cimetidine and it itself can inhibit antipyrine metabolism.
The systemic absorption of Piroxiferum 0.5% Gel is very low. In common with other topical NSAIDs, systemic reactions occur infrequently. Mild to moderate local irritation, erythema, pruritus, and dermatitis may occur at the application site.
Gastrointestinal: nausea, dyspepsia, abdominal pain and gastritis have been reported.
Respiratory, thoracic and mediastinal disorders: There have been isolated reports of bronchospasm and dyspnoea.
Skin and subcutaneous tissue disorders: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) have been reported very rarely.
Contact dermatitis, eczema and photosensitivity skin reaction have also been observed from post-marketing experience.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme (Website: www.mhra.gov.uk/yellowcard).
There are no preclinical data of relevance to the prescriber which are additional to those included elsewhere in the SPC.
Piroxiferum gel is a non-steroidal anti-inflammatory agent indicated for a variety of conditions characterised by pain and inflammation, or stiffness. It is effective in the treatment of osteoarthritis of superficial joints such as the knee, acute musculoskeletal injuries, periarthritis, epicondylitis, tendinitis, and tenosynovitis.
Pharmacotherapeutic group: Anti-inflammatory preparations, non-steroids for topical use (ATC code M02AA07).
Piroxiferum inhibits the enzyme cyclo-oxygenase. This is a basic characteristic of non-steroidal anti-inflammatory drugs, which allows them to influence many physiological processes.
Depending on the site of action, NSAID may;
- reduce the vascular phase of inflammation,
- decrease sensitisation of nociceptors to stimulation,
- act as an antipyretic,
- inhibit the secondary phase of platelet aggregation,
- affect the motility of bronchi and of the uterus,
- cause a dose dependent decrease in renal blood flow particularly in patients with renal impairment,
- lead to the activation of free radicals by neutrophils,
- affect the permeability of the foetal umbilical arterial canal,
- interfere with the renal resorption of uric acid,
- affect the gastric mucosa leading to ulceration of the muscularis mucosa.
Piroxiferum's pharmacological profile is based on the inhibition of prostaglandin synthesis from arachidonic acid in vitro, of collagen-induced aggregation of human and animal platelets in vitro, of the release of lysosomal enzymes, of the generation of the reactive superoxide anion, of chemostaxis/migration of neurophils, macrophages, monocytes, platelets, of the carrageenin-induced foot oedema in rats, of the benzoquinone-induced writhing in mice, of E.coli-induced fever in rats and of urate crystal-induced synovitis.
A study in man examining skin biopsies following Piroxiferum gel administration concluded that Piroxiferum rapidly permeates through the stratum corneum into the epidermis/dermis after application of the gel with plasma levels being low.
A separate study in man demonstrated mean plasma concentrations of Piroxiferum gel to be approximately 5% of those observed after equivalent doses of oral or intramuscular Piroxiferum. In healthy subjects or patients following the administration of a single oral dose, the pharmacokinetics of Piroxiferum are linear, with maximum plasma concentration usually being obtained in about 2 h, but this can vary from 1-6 h in different subjects. It has a low clearance rate of approximately 45 h, but the half-life can vary from 30-60 h. After repeated doses of 20 mg daily, steady - state concentrations are generally achieved in 7-12 days; with a peak plasma concentration ranging from 4.5-2.2 mg/l.
In humans it penetrates into the synovial fluid of patients with rheumatoid arthritis, osteoarthritis, and reactive synovitis where mean concentrations are approximately 40% of those in plasma; it is also demonstrable in synovial tissues. Concentrations of Piroxiferum in breast milk are about 1% of those in the maternal plasma at the same time. Overall, Piroxiferum is 99% bound to plasma protein. Pharmacokinetics of the drug do not appear to be age related, and renal function has only a limited influence on its elimination, but plasma concentrations are increased in patients with severe liver dysfunction.
Piroxiferum is eliminated by biotransformation in the liver. The major route is by hydroxylation, with the resultant products being excreted alone or as a glucuronide in urine and faeces. The metabolites of Piroxiferum have little or no anti-inflammatory activity in animal models. Approximately 10% of an oral dose is excreted as unchanged drug in 10 days.
Piroxiferum 0.5% Gel is not suitable for use in children under 12 years of age.
The gel should not be used for any condition other than those specified.
Life-threatening cutaneous reactions (Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)) have been reported with the systemic administration of Piroxiferum. These reactions have not been associated with topical Piroxiferum, but the possibility of occurring with topical Piroxiferum cannot be excluded.
Patients should be advised of the signs and symptoms and monitored closely for skin reactions. The highest risk for occurrence of SJS or TEN is within the first weeks of treatment.
If symptoms or signs of SJS or TEN (e.g. progressive skin rash often with blisters or mucosal lesions) are present, Piroxiferum treatment should be discontinued.
The best results in managing SJS and TEN come from early diagnosis and immediate discontinuation of any suspect drug. Early withdrawal is associated with a better prognosis.
If the patient has developed SJS or TEN with the use of Piroxiferum, Piroxiferum must not be re-started in this patient at any time.
If local irritation develops, the use of the gel should be discontinued and appropriate therapy instituted as necessary.
Keep away from the eyes and mucosal surfaces. Do not apply to any sites affected by open skin lesions, dermatoses or infection.
NSAIDs, including Piroxiferum, may cause interstitial nephritis, nephrotic syndrome and renal failure. There have also been reports of interstitial nephritis, nephrotic syndrome and renal failure with topical Piroxiferum, although the causal relationship to treatment with topical Piroxiferum has not been established. As a result, the possibility that these events may be related to the use of topical Piroxiferum cannot be ruled out.
None known.
Piroxiferum Gel is for external use only. No occlusive dressings should be employed.
Apply 1g of gel, corresponding to 3cm, and rub into the affected site three to four times daily leaving to residual material on the skin. Therapy should be reviewed after 4 weeks.
Use in Children: Dosage recommendations and indications for use of Piroxiferum Gel in children have not been established.
Use in the elderly: No special precautions are required.
Pierce the tube by reversing the cap and screwing down to break the seal on the tube. Apply 3cm (1¼†approximately) of the gel on the affected area. Rub the gel into the skin until the gel disappears. Do this three or four times a day. For muscle sprains and strains, you should start to feel better within one week. If the pain has not got any less after a week, tell your pharmacist or doctor. Replace the cap after use.
Wash hands after each application unless it is the hand that is being treated.
