Monograph: |
Mephenesin
.
Adverse Effects
Given by mouth, mephenesin may produce lassitude, drowsi-
ness, weakness, loss of appetite, nausea, and vomiting. Aller-
gic reactions may rarely occur. Overdosage may produce
visual disturbances, motor incoordination, hypotonia, a fall in
blood pressure, and respiratory paralysis.
Precautions
Mephenesin may cause drowsiness: patient* affected should
not drive or operate machinery.
Porphyria. Mephenesin was considered to be unsafe in pa-
tients with acute porphyria because it has been shown to be
porphyrinogenic in animals or in-vitro systems.'
Interactions
The CNS effects of mephenesin may be enhanced by alcohol
or other CNS depressants.
Pharmacokinetics
Mephenesin is readily absorbed from the gastro-intestinal
tract and distributed throughout most tissues of the body. It is
metabolised mainly in the liver and excreted in urine as me-
tabolites and a small amount of unchanged drug.
Uses and Administration
Mephenesin is a centrally acting skeletal muscle relaxant
used for the symptomatic treatment of painful muscle spasm
associated with musculoskeletal conditions. Its clin-
ical usefulness is considered to be limited by its brief duration
of action. It is given by mouth in doses of 1.5 to 3 g daily in
divided doses. It is also applied topically, usually with rube-
facients.
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