Loxoprofen

Loxoprofen (INN) is a non-steroidal anti-inflammatory drug in the propionic acid derivatives group, which also includes ibuprofen and naproxen among others. It is marketed in Brazil, Mexico and Japan by Sankyo as its sodium salt, Loxoprofen sodium, under the trade name Loxonin, Argentina as Oxeno and in India as Loxomac. It is available in these countries for oral administration, and a transdermal preparation was approved for sale in Japan on January 2006.

Loxoprofen has anti-inflammatory and analgesic effects on the following diseases and symptoms: Chronic articular rheumatism, osteoarthritis, lumbago, periarthritis of the shoulder and shoulder-arm-neck syndrome.

Loxoprofen relieves pain and inflammation after operation, trauma and tooth extraction.

For general use, 60 mg of Loxoprofen sodium (as anhydrous) is orally administered to adults 3 times a day.

For a single administration, 60-120 mg is orally given.

The dosages should be adjusted according to age and symptoms.

Loxoprofen tablets or ibuprofen childrens suspension should not be used in patients who have previously exhibited hypersensitivity to the drug, or in individuals with the syndrome of nasal polyps, angioedema, and bronchospastic reactivity to aspirin or other nonsteroidal anti-inflammatory agents. Anaphylactoid reactions have occurred in such patients.

Coumarin-Type Anticoagulants: Several short-term controlled studies failed to wshow that ibuprofen significantly affected prothrombin times or a variety of other clotting factors when administered to individuals on coumarin-type anticoagulants. However, because bleeding has been reported when ibuprofen and other nonsteroidal anti-inflammatory agents have been administered to patients on coumarin-type anticoagulants, the physician should be cautious when administering ibuprofen to patients on anticoagulants.

Aspirin: Animal studies wshow that aspirin given with nonsteroidal anti-inflammatory agents, including ibuprofen, yields a net decrease in anti-inflammatory activity with lowered blood levels of the non-aspirin drug. Single dose bioavailability studies in normal volunteers have failed to wshow an effect of aspirin on ibuprofen blood levels. Correlative clinical studies have not been performed.

Methotrexate: Loxoprofen, as well as other nonsteroidal anti-inflammatory drugs, probably reduces the tubular secretion of methotrexate based on in vitro studies in rabbit kidney slices. This may indicate that ibuprofen could enhance the toxicity of methotrexate. Caution should be used if ibuprofen is administered concomitantly with methotrexate.

H-2 Antagonists: In studies with human volunteers, co-administration of cimetidine or ranitidine with ibuprofen had no substantive effect on ibuprofen serum concentrations.

Furosemide: Clinical studies, as well as random observations, have shown that ibuprofen 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 ibuprofen, the patient should be observed closely for signs of renal failure, as well as to assure diuretic efficacy.

Lithium: Loxoprofen produced an elevation of plasma lithium levels and a reduction in renal lithium clearance in a study of eleven normal volunteers. The mean minimum lithium concentration increased 15% and the renal clearance of lithium was decreased by 19% during this period of concomitant drug administration.

This effect has been attributed to inhibition of renal prostaglandin synthesis by ibuprofen. Thus, when ibuprofen and lithium are administered concurrently, subjects should be observed carefully for signs of lithium toxicity. (Read circulars for lithium preparation before use of such concurrent therapy).

Adverse GI effects, anorexia, vomiting, diarrhoea, constipation. Anaemia, leucopenia, thrombocytopenia.