Symptoms and Treatment of Overdose: Bluish skin, clammy skin, colic, coma, confusion, diarrhoea (may be bloody), difficult and/or slow breathing, dizziness, fainting, fever, flushed skin, persistent, throbbing headache, increased pressure within the skull, irregular pulse, loss of appetite, nausea, palpitations (an abnormally rapid throbbing or fluttering of the heart), paralysis, rapid decrease in blood pressure, seizures, slow or fast pulse/heartbeat, sweating, vertigo, visual disturbances, vomiting. If these occur, dose should be reduced.