The mode of action of the drug has not been clearly identified, but may be related to its analgesic properties. Orphenadrine citrate does not directly relax tense skeletal muscles in man. Contraindicated in patients who have demonstrated a previous hypersensitivity to the drug. Some patients may experience transient episodes of light-headedness, dizziness or syncope. The overall prevalence of sulfite sensitivity in the general population is unknown and probably low.
Sulfite sensitivity is seen more frequently in asthmatic than nonasthmatic people.
Pregnancy Category C. Animal reproduction studies have not been conducted with Norflex. It is also not known whether Norflex can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Norflex should be given to a pregnant woman only if clearly needed. Confusion, anxiety and tremors have been reported in few patients receiving propoxyphene and orphenadrine concomitantly. Orphenadrine citrate should be used with caution in patients with tachycardia, cardiac decompensation, coronary insufficiency, cardiac arrhythmias.