CATEGORY:
Nonsteroidal Anti-inflammatory.
MECHANISM OF ACTIONS :
The effectiveness of Naproxen is due partly to
its ability to inhibit cycloxygenase 1 and 2.
Naproxen as such irreversibly blocks the enzyme
cycloxygenase (prostaglandin synthase), which
catalyzes to conversion of arachidonic acid to
endoperoxide compounds; at appropriate doses,
the drug decreases the formation of both the
prostaglandins and thromboxane A2 but not the
leukotrienes.
PHARMACOKINETICS:
Naproxen is a naphthylpropionic acid . It is
also well absorbed following rectal
administration but absorption is slower compared
with the oral route .
INDICATIONS:
Rheumatic diseases; for anti-inflammatory and
analgesic action in rheumatoid arthritis,
Juvenile chronic arthritis, osteoarthritis,
Ankylosing spondylitis and synovitis,
tenosynovitis and lumbago.
Periarticular and musculoskeletal:for analgesia
in bursitis, Tentinitis, Synovitis,
Aenosynovitis and lumbago.
Prophylaxis and treatment of migraine headache.
Infectious disease: for analgesic,
anti-inflammatory and antipyretic purposes.
Gynaecological uses-in dysmenorrhoea, following
IUD insertion and for uterine relaxation and
analgesia in the postpartum non-nursing mother.
DRUG INTERACTIONS :
Drugs that enhance Salicylate intoxication
include Acetazolamide and ammonium chloride.
Alcohol increases gastrointestinal bleeding
produced by Naproxen .Naproxen displace a number
of drugs from protein binding sites in the blood
.These include Tolbutamide , Chlorpropamide, non
steroidal anti inflammatory agents, Methotrexate,
Phenytoin, and probencid. Naproxen reduces the
pharmacologic activity of Spironolactone and
competes with penicillin G for renal tubular
secretion, and also inhibits the Uricosuric
effect of Sulfinpyrazone and probenecid .
ADVERSE EFFECTS :
Naproxen is generally well tolerated compared
with other NSAIDs.
Headache, dizziness, drowsiness and tinnitus are
the most commonly reported effects . GI tract
toxicity such as bleeding , ulceration and
perforation can occur .Local irritation and
occasionally rectal bleeding may occur with
naproxen suppositories . |
