Some people do agree on GUAIFENESIN's effectiveness in the treatment of fibromyalgia but for other reasons than those evoked by Dr. St. Amand phosphate retention theory. They attribute its effectiveness on the disease to other modes of action:
1) To its muscular relaxant property, acting on the neuromuscular transmission. If GUAIFENESIN in pills or capsules is not usually prescribed for this indication, some doctors – I belong to them - do use transdermal GUAIFENESIN in cream or gel for its remarkable myorelaxant efficacy. GUAIFENESIN in cream or gel associated with antalgic drugs in a same transdermal preparation is currently prescribed for local pains in pain clinic centers. GUAIFENESIN is in use in intra-venous injections for surgery
premedication in veterinary medicine.
2) To its property to inhibit the activity of the NMDA neuroreceptors, as are acting some antalgic drugs like Dextromethorphan, Ketamine orTramadol.
3) To its antagonist action on EAA (excitatory aminoacids) which are mediators of the synaptic excitation and thus of the nervous signal transmission. Researches have shown high levels of EAA in fibromyalgia. EAA are believed to be involved in the pain process.
4) To its ability to increase the antalgic effect of paracetamol.
5) To an uricouric effect.
6) To an anxiolytic effect.
All those well documented evidences showing different modes of action of GUAIFENESIN, give proof why people suffering from fibromyalgia benefit from this treatment. In fact, it doesn't matter how GUAIFENESIN works, if the phosphate retention theory explains or not an underlying cause, the main point to keep in mind is its effectiveness.