Flufenaminsäure: Anthranilsäure Derivat as Topical NSAR (Fenamate)
Flufenaminsäure is a non-steroidal anti-inflammatory drug (NSAR) from the class of fenamtes (anthranilsäure derivatives). Well-known brand names are Mobilisin Gel and Mobilat (in combination with salicylic acid and heparinoid). In Germany, flufenaminsäure is used almost exclusively topically in the form of creams and gels for rheumatic complaints, contusions and sprains. Oral use of fenamtes is rarely widespread in Germany, in some countries mefenamic acid is used as an oral pain reliever for dysmenorrhoea and migraine.
Fenamtes belong to the older NSARs and have a fixed place in the topical therapy of musculoskeletal complaints. Compared to modern topical NSARs such as diclofenac gel or ibuprofen gel, the data on flufenaminsäure is limited, with comparable clinical efficacy.
Mechanism of Action
Flufenaminsäure non-selectively inhibits cyclooxygenase 1 and 2 (COX 1 and COX 2) in tissues and thereby reduces the synthesis of prostaglandins from arachidonic acid. Prostaglandins mediate inflammation, pain and fever, their reduction leads to anti-inflammatory, analgesic and antipyretic effects.
In addition, flufenaminsäure inhibits some other inflammatory mediators such as leukotriene synthesis and affects calcium and chloride channels in cells, which may be relevant in specific tissues such as glia and muscle cells. These multiple effects distinguish fenamtes in part from other NSARs.
Pharmacokinetically, flufenaminsäure is absorbed locally in skin and subcutaneous tissue when applied topically, with only low systemic absorption (approximately 5 to 10 percent of the applied amount). Half-life after systemic absorption approximately 9 hours, elimination renal after hepatic metabolism.
Indications
- Blunt injuries: Contusions, sprains, strains with local swelling and pain
- Tenosynovitis, bursitis: Inflammatory tendon and bursa diseases
- Post-traumatic and post-operative swelling
- Rheumatic complaints: Periarthritis, shoulder-arm syndrome, lumbago
- Sports injuries: Muscle fiber tear, edema, contusion
- Hematomas: Superficial bruises
Dosage and Administration
Topical application: Apply 5 to 10 cm of gel or ointment to the affected area and gently massage in, two to three times daily. Duration of application is usually until symptoms resolve, not longer than 2 weeks without medical consultation.
Before application: Skin should be clean, dry and intact. Avoid application to open wounds, mucous membranes or eczematous skin. After application, wash hands thoroughly to avoid accidental contact with eyes or mucous membranes.
During pregnancy: particularly in the third trimester, topical application over large areas should be avoided; small amounts on localized skin areas are possible after risk-benefit assessment. If necessary, discuss with your medical practice.
Adverse Effects
Frequent: Usually well tolerated. Local skin reactions such as redness, burning, pruritus, mild skin rash.
Occasional: Allergic contact dermatitis, photosensitivity, dermatitis.
Rare: Systemic NSAR adverse effects such as gastrointestinal complaints with large-area application, anaphylactoid reactions, bronchospasm in NSAR allergy, worsening asthma.
Important: With large-area or long-term topical application, systemic absorption can trigger clinically relevant NSAR adverse effects, particularly in patients with renal insufficiency, heart failure or NSAR allergy.
Drug Interactions
- Other NSARs (oral or topical): Additive risks, avoid combination
- Anticoagulants (Warfarin, NOAK): With large-area application, possible increase in bleeding risk
- Glucocorticoids topical or systemic: Additive skin reactions or gastrointestinal risks
- Photosensitizing substances: Intensified photodermatosis reaction possible
Special Information
Pregnancy and lactation: NSARs are avoided in the third trimester due to risk of premature closure of the ductus arteriosus and renal effects on the fetus. Topical application of small amounts is usually acceptable, large-area application should be avoided. In the first and second trimesters, restrictive use.
With NSAR allergy: Topical application can also trigger a reaction in patients with known NSAR allergy, therefore contraindicated.
Photosensitivity: Patients should avoid direct sunburn and solarium use on treated skin areas, as flufenaminsäure can increase UV sensitivity.
Diagnostics: In cases of unusual swelling, persistent complaints over several weeks or unclear cause, medical evaluation is important to avoid missing serious conditions such as thrombosis, fracture, tendon rupture.
You might also be interested in
- Diclofenac, classic topical NSAR
- Ibuprofen, another NSAR oral and topical
- Heparin, often combined in topical pain gels
- Aescin, herbal alternative for swelling
- Etofenamat, another fenamate derivative
Frequently Asked Questions
Does flufenaminsäure gel really help with sprains?
Topical NSARs are effective in studies for acute sports injuries, with moderate pain relief and reduction of swelling. Efficacy is comparable to diclofenac gel or ibuprofen gel. Important accompanying measures are cooling, compression and elevation (RICE regimen), which work in addition to local therapy.
When should I see a doctor?
In case of severe pain, pronounced swelling, restricted movement, marked bruise formation, deformity or suspicion of bone fracture, tendon rupture or ligament injury, medical evaluation should be sought promptly. With one-sided leg swelling, thrombosis may be present and should be medically evaluated.
Can I combine flufenaminsäure gel with oral NSARs?
With short-term application of small amounts, the combination is usually safe. With large-area or long-lasting topical application, however, systemic NSAR effects can accumulate with increased risk of gastrointestinal complaints, renal function impairment or blood pressure elevation. In case of doubt, discuss with your medical practice or pharmacy.
Can I apply flufenaminsäure to open wounds?
No. The gel should not be applied to open wounds, mucous membranes, eczematous or infected skin, as systemic absorption is greatly increased and local irritation can be worsened.
Sources
- Gelbe Liste, Flufenaminsäure drug profile
- Cochrane Reviews on topical NSARs for musculoskeletal complaints
- BfArM, Federal Institute for Drugs and Medical Devices
- EMA Product Information Flufenaminsäure preparations
Legal Information and Disclaimer
The information provided on this page is for general informational purposes only and does not constitute medical advice, diagnosis or treatment recommendation. It does not replace the advice of a licensed physician or pharmacist. Medicines should always be taken only on medical prescription or pharmaceutical dispensing. All information is based on product information published at the time of creation and recognized scientific sources; the current product information from the manufacturer is always authoritative. Sanoliste assumes no liability for completeness, timeliness or accuracy of the information presented. In case of a medical emergency, call the emergency number 112.