Other likely symptoms include convulsions, neuromuscular symptoms, shock, loss of consciousness, hypotension, ataxia, excessive salivation, limb paralysis, nausea and vomiting, fever, and severe abdominal pain.
Symptoms that suggest the presence of metastatic disease include weight loss, bone pain and neurological symptoms (headaches, fainting, convulsions, or limb weakness).
Activation of receptors by an agonist ligand may induce hallucinogenic effects and also may be responsible for the paradoxical convulsions sometimes seen in opiate overdose.
