Absolutely it can. Colloidal silver is deadly to almost every pathogen known to man, and likely some parasites too. Herxheimer effects are common and your body will signal a need to sleep, where nature's healing is best. So you are likely to feel worse before you feel better, but it should be temporariy and within just a matter of days you should begin feeling much better in most instances.
See:The Herxheimer Reaction - Feeling worse before feeling better