Can a caregiver be harassed by creditor phone calls when the debtor is not coherent at this time to take phone calls or transact business?

The caregiver has no obligation (nor is it legal in some situations) to discuss the incapacitated person's medical or financial issues. A temporary solution would be to use caller ID, voice mail or other type actions to screen out collection calls. The best option is to consult an attorney who is versed in Elder Law and/or bankruptcy. A person who is unable to manage their finances is protected by state and federal laws. In most cases there will be held in the court of jurisdiction (usually probate) to determine if the person is incompetent. If that is the case, an ad litem is appointed to oversee the care (including all finances) of the incompetent person. Whenever possible the court prefers to appoint a adult family member as guardian/conservator. Usually one person acts as both, the first choice obviously being a spouse, then adult children, siblings, etc. It is strictly a voluntary position, the court cannot force anyone to accept the responsibility.