Nefopam MAOIs

MAOIs NEFOPAM Risk of arrhythmias Additive effect both drugs have sympathomimetic effects Avoid co-administration... 

The manufacturer states that nefopam should not be given to patients taking non-selective MAOIs and caution should be used in those taking tricyclic antidepressants, antimuscarinics and sym-pathomimetics. The intensity and incidence of adverse effects are somewhat increased when nefopam is given with codeine, pentazocine or dextropropoxyphene (propoxyphene), and the CNS depressant effect of dihydrocodeine may have contributed to a fatal overdose with nefopam. However, a morphine-sparing effect has been reported. Nefopam may also have a synergistic analgesic effect with ketoprofen. 

Detailed information about adverse interactions between nefopam and other drugs does not seem to be available. The manufacturer advises caution if nefopam is given with a tricyclic antidepressant because they lower the convulsive threshold convulsions have been seen in some patients taking nefopam. In addition, the antimuscarinic adverse effects of nefopam may be additive with those of tricyclics and other drugs with antimuscarinic effects. For example, the CSM in the UK has a number of reports of urinary retention caused by nefopam, which would be expected to be worsened by drugs with antimuscarinic activity. Nefopam appears to have sympathomimetic activity and the manufacturer therefore says it should not be given with the MAOIs (see MAOIs or RIMAs + Sym-pathomimetics Indirectly-acting , p.l 147). 

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