Difen Plus

A biguanide hypoglycemic agent with actions and uses similar to those of metformin. Although it is generally considered to be associated with an unacceptably high incidence of lactic acidosis, often fatal, it is still available in some countries. (From Martindale, The Extra Pharmacopoeia, 30th ed, p290)

Articular syndrome (rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, gout), degenerative and chronic inflammatory diseases of musculoskeletal system (osteochondrosis, osteoarthritis, periartropatii), post-traumatic inflammation of soft tissue and musculoskeletal system (sprains, bruises). Pain in the spine, neuralgia, myalgia, arthralgia, pain and inflammation after surgery or injury, pain in gout, migraine, algomenorrhea, pain with Bursitis, proctitis, colic (biliary and renal), pain in infectious and inflammatory diseases of ENT organs.

For local use: the inhibition of miosis during surgery for cataract prevention of cystoid macular edema associated with removal and lens implantation, inflammatory eye non-infectious nature, post-traumatic inflammation in penetrating and nonpenetrating wound of the eyeball.

For oral use for adult single dose is 25-50 mg 2-3 times / 24 h. Frequency of admission depends on the dosage form employed, the severity of the disease and is 1-3 times / 24 h, rectally - 1 times / 24 h, for the treatment of acute conditions or the exacerbation of chronic edema use intramuscular in dose of 75 mg.

For children older than 6 years and adolescents daily dose is 2 mg / kg.

Topical applied at a dose of 2-4 g (depending on the size of painful area) on the affected area 3-4 times / 24 h.

When used in ophthalmology frequency and duration of administration are determined individually.

The maximum oral daily dose for adults is 150 mg.

Difen Plus should not be administered to patients who have previously exhibited hypersensitivity to it.

The use of NSAIDs in patients who are receiving ACE inhibitors may potentiate renal disease states.

In vitro studies have shown that naproxen anion, because of its affinity for protein, may displace from their binding sites other drugs which are also albumin-bound.

Theoretically, the naproxen anion itself could likewise be displaced. Short-term controlled studies failed to show that taking the drug significantly affects prothrombin times when administered to individuals on coumarin-type anticoagulants. Caution is advised nonetheless, since interactions have been seen with other nonsteroidal agents of this class. Similarly, patients receiving the drug and a hydantoin, sulfonamide or sulfonylurea should be observed for signs of toxicity to these drugs.

Concomitant administration of naproxen and aspirin is not recommended because naproxen is displaced from its binding sites during the concomitant administration of aspirin, resulting in lower plasma concentrations and peak plasma levels.

The natriuretic effect of furosemide has been reported to be inhibited by some drugs of this class. Inhibition of renal lithium clearance leading to increases in plasma lithium concentrations has also been reported. Difen Plus and other NSAIDs can reduce the antihypertensive effect of propranolol and other beta-blockers.

Probenecid given concurrently increases naproxen anion plasma levels and extends its plasma half-life significantly.

Caution should be used if naproxen is administered concomitantly with methotrexate. Difen Plus, naproxen sodium and other NSAIDs have been reported to reduce the tubular secretion of methotrexate in an animal model, possibly increasing the toxicity of methotrexate.

Drug/Laboratory Test Interactions

Difen Plus may decrease platelet aggregation and prolong bleeding time. This effect should be kept in mind when bleeding times are determined. The administration of naproxen may result in increased urinary values for 17-ketogenic steroids because of an interaction between the drug and/or its metabolites with m-dinitrobenzene used in this assay. Although 17-hydroxy-corticosteroid measurements (Porter-Silber test) do not appear to be artifactually altered, it is suggested that therapy with naproxen be temporarily discontinued 72 hours before adrenal function tests are performed if the Porter-Silber test is to be used.

Difen Plus may interfere with some urinary assays of 5-hydroxy indoleacetic acid (5HIAA).

GI disturbances; headache, dizziness, rash; GI bleeding, peptic ulceration; abnormalities of kidney function. Pain and tissue damage at Inj site (IM); local irritation (rectal); transient burning and stinging (ophthalmic).

Potentially Fatal: Stevens-Johnson syndrome, exfoliative dermatitis, toxic epidermal necrolysis.