Pralidoxime Chloride (2PAMCl) - Aging                                              3 of 3

 

The bond between the enzyme and the nerve agent can age, a process by which the enzyme and agent become irreversibly bound.

 

Sarin

The half time for aging of sarin is 4 to 5 hours; this means that half of the bound sarin-enzyme complex can be reactivated 4-5 hours after sarin exposure by administration of the antidote. The complete time for aging of sarin is about 10 times the half time (40-50 hours), and at this point the bond becomes permanent.

 

VX

The half time for aging of the VX-enzyme complex is 60 hours.
 

Soman (GD)

Usually, there is plenty of time to treat patients with 2-PAMCl after exposure to nerve agents - GD is the exception.   The soman-enzyme complex ages in about 2 minutes. However, it is likely that this will not be significant for two reasons:

•        The exact identity of the chemical agent (Soman vs. other nerve agents) will likely be unknown immediately after an attack.

•        The amount of 2-PAMCl used will not harm the patient.