A1,
A2,
B,
C1,
C2,
D,
E,
F,
G-H,
I-K,
L,
M,
N,
O,
P1,
P2,
Q-R,
S,
T,
U-V,
W-Z
Ponstel Side Effects, and Drug Interactions - Mefenamic Acid
Ponstel Side Effects, and Drug Interactions - Mefenamic Acid
SIDE EFFECTS
In patients taking Ponstel or other NSAIDs, the most frequently reported
adverse experiences occurring in approximately 1-10% of patients are:
Gastrointestinal: abdominal pain, constipation, diarrhea,
dyspepsia, flatulence, gross bleeding/perforation, heartburn, nausea,
GI ulcers (gastric/duodenal), vomiting, abnormal renal function, anemia,
dizziness, edema, elevated liver enzymes, headaches, increased bleeding
time, pruritus, rashes, tinnitus.
Additional adverse experiences reported occasionally and listed here
by body system include:
Body as a Whole: fever, infection, sepsis.
Cardiovascular System: congestive heart failure, hypertension,
tachycardia, syncope.
Digestive System: dry mouth, esophagitis, gastric/peptic
ulcers, gastritis, gastrointestinal bleeding, glossitis, hematemesis,
hepatitis, jaundice.
Hemic and Lymphatic System: ecchymosis, eosinophilia, leukopenia,
melena, purpura, rectal bleeding, stomatitis, thrombocytopenia.
Metabolic and Nutritional: weight changes.
Nervous System: anxiety, asthenia, confusion, depression,
dream abnormalities, drowsiness, insomnia, malaise, nervousness, paresthesia,
somnolence, tremors, vertigo.
Respiratory System: asthma, dyspnea.
Skin and Appendages: alopecia, photosensitivity, pruritus,
sweat.
Special Senses: blurred vision.
Urogenital System: cystitis, dysuria, hematuria, interstitial
nephritis, oliguria/polyuria, proteinuria, renal failure.
Other adverse reactions, which occur rarely are:
Body as a Whole: anaphylactoid reactions, appetite changes,
death.
Cardiovascular System: arrhythmia, hypotension, myocardial
infarction, palpitations, vasculitis.
Digestive System: eructation, liver failure, pancreatitis.
Hemic and Lymphatic System: agranulocytosis, hemolytic anemia,
aplastic anemia, lymphadenopathy, pancytopenia.
Metabolic and Nutritional: hyperglycemia.
Nervous System: convulsions, coma, hallucinations, meningitis.
Respiratory: respiratory depression, pneumonia.
Skin and Appendages: angioedema, toxic epidermal necrosis,
erythema multiforme, exfoliative dermatitis, Stevens- Johnson syndrome,
urticaria.
Special Senses: conjunctivitis, hearing impairment.
DRUG INTERACTIONS
Aspirin: As with other NSAIDs, concomitant administration
of Ponstel and aspirin is not generally recommended because of the potential
of increased adverse effects.
Methotrexate: NSAIDs have been reported to competitively
inhibit methotrexate accumulation in rabbit kidney slices. This may indicate
that they could enhance the toxicity of methotrexate. Caution should be
used when NSAIDs are administered concomitantly with methotrexate.
ACE inhibitors: Reports suggest that NSAIDs may diminish
the antihypertensive effect of ACE inhibitors. This interaction should
be given consideration in patients taking NSAIDs concomitantly with ACE
inhibitors.
Furosemide: Clinical studies, as well as post-marketing
observations, have shown that NSAIDs 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
of Ponstel with furosemide, the patient should be observed closely for
signs of renal failure (see PRECAUTIONS:
Renal Effects), as well as to assure diuretic efficacy.
Lithium: NSAIDs have produced an elevation of plasma lithium
levels and a reduction in renal lithium clearance. The mean minimum lithium
concentration increased 15% and the renal clearance was decreased by approximately
20%. These effects have been attributed to inhibition of renal prostaglandin
synthesis by the NSAID. Thus, when NSAIDs and lithium are administered
concurrently, subjects should be observed carefully for signs of lithium
toxicity.
Warfarin: The effects of warfarin and NSAIDs on GI bleeding
are synergistic, such that users of both drugs together have a risk of
serious GI bleeding higher than users of either drug alone.
Antacids: In a single dose study (n=6), ingestion of an
antacid containing 1.7-gram of magnesium hydroxide with 500-mg of mefenamic
acid increased the Cmax and AUC of mefenamic acid by 125% and 36%, respectively.¹
A number of compounds are inhibitors of CYP2C9 including fluconazole,
lovastatin and trimethoprim. Drug interaction studies of mefenamic acid
and these compounds have not been conducted. The possibility of altered
safety and efficacy should be considered when Ponstel is used concomitantly
with these drugs.
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