NONSTEROIDAL ANTI-INFLAMMATORY DRUGS

Nonsteroidal anti-inflammatory drugs (NSAIDs),
often referred to as ‘aspirin-like drugs’, are a
heterogeneous group of anti-inflammatory, analgesic
and antipyretic compounds. These are often
chemically unrelated (although most of them are
organic acids), but share certain therapeutic actions
and side-effects.
Mechanisms of action
The NSAIDs largely act by irreversibly blocking the
enzyme cyclo-oxygenase, thus inhibiting the
prostaglandin biosynthesis. They also appear to block
other local mediators of the inflammatory response
such as polypeptides of the kinin system, lysosomal
enzymes, lymphokinase and thromboxane A2; but not
the leukotrienes.
Preparations
A. NSAIDs available for systemic use can be
grouped as follows:
1. Salicylates e.g., aspirin.
2. Pyrazolone derivatives e.g., phenylbutazone,
oxyphenbutazone, aminopyrine and apazone.
3. Para-aminophenol derivatives e.g., phenacetin
and acetaminophen.
4. Indole derivatives e.g., indomethacin and
sulindac.
5. Propionic acid derivatives e.g., ibuprofen,
naproxen and flurbiprofen.
6. Anthranilic acid derivatives e.g., mefenamic
acid and flufenamic acid.
7. Other newer NSAIDs e.g., ketorolac tromethamine,
carprofen and diclofenac.
B. Topical ophthalmic NSAIDs preparations
available include:
1. Indomethacin suspension (0.1%)
2. Flurbiprofen, 0.3% eyedrops
3. Ketorolac tromethamine, 0.5% eyedrops
4. Diclofenac sodium, 0.1% eyedrops
Ophthalmic indications of NSAIDs
1. Episcleritis and scleritis. Recalcitrant cases of
episcleritis may be treated with systemic NSAIDs
such as oxyphenbutazone 100 mg TDS or
indomethacin 25 mg BD.
NSAIDs may also suppress the inflammation in
diffuse and nodular varieties of scleritis, but are
not likely to control the necrotizing form.
2. Uveitis. NSAIDs are usually not used as the
primary agents in therapy of uveitis. They are,
however, useful in the long-term therapy of
recurrent anterior uveitis, initially controlled by
steroid therapy. Phenylbutazone is of use in
uveitis associated with ankylosing spondylitis.
3. Cystoid macular oedema (CME). Topical and/or
systemic antiprostaglandin drugs are effective in
preventing the postoperative CME occurring after
cataract operation. The drug (e.g., 0.03%
flurbiprofen eyedrops) is started 2 days
preoperatively and continued for 6-8 weeks postoperatively.
4. Pre-operatively to maintain dilatation of the
pupil. Flurbiprofen drops used every 5 minutes
for 2 hours preoperatively are very effective in
maintaining the pupillary dilatation during the
operation of extracapsular cataract extraction with
or without intraocular lens implantation.
5. Spring catarrh. Sodium cromoglycate 2 percent
inhibits degranulation of the mast cells and thus
is more useful when used prophylactically in
patients with spring catarrh. Topical
antiprostaglandins are effective in the treatment
of spring catarrh.
6. Topical antihistaminics are helpful in cases of
mild allergic conjunctivitis.