Overdose : מינון יתר

4.9 Overdose

Signs and symptoms encountered with overdose are generally similar to those events reported during treatment use although the magnitude and/or severity of the reactions may be more pronounced (see Adverse Reactions).
Flushing, severe headache, a feeling of suffocation, hypotension, fainting, restlessness, blurred vision, impairment of respiration, bradycardia and rarely, cyanosis and methaemoglobinaemia may occur. In a few patients there may be a reaction comparable to shock with nausea, vomiting, weakness, sweating and syncope.
At very high doses an increase in intracranial pressure with cerebral symptoms may occur. Additional gastrointestinal effects such as colicky pain and diarrhoea have also been reported.
Treatment


In the case of overdose, the patient's clinical status including vital signs and mental status should be assessed and supportive treatment of the cardiovascular and respiratory systems provided as clinically indicated or as recommended by the national poisons centre, where available.
In the event of mild hypotension, passive elevation of the patient's legs and/or lowering of the head may be effective.
Arterial blood gas estimation should be performed and if there is acidosis or the patient is clinically cyanosed, then severe methaemoglobinaemia must be assumed. Oxygen therapy should be given with 1 to 2 mg/kg bodyweight of i.v.
Methylene Blue over five min unless the patient is known to have G- 6-PD deficiency.