Has Dementia And Alzeimers. Taking Aricep, Respidon And Pacitane. Almost Mute, Excess Saliva And Violent.

Managing Behavioural and Psychological Symptoms in Dementia (BPSD) is not easy. The responses to medications is not very smooth and predictable. There will be a lot of variation from week to week and month to month.
You have described the typical problem in your father's case.

Increasing medications bring temporary relief from agitation, suspiciousness or aggression; however people with dementia are also sensitive to side-effects of the medications. This will require a reduction in dosage.
You may consult your doctor regularly whenever problems arise.
Reducing dosage of medications has the risk of worsening aggression. It is a calculated risk.

In addition you may use certain methods to control or reduce aggression:-

1) Since dementia is associated with memory loss, you will notice that the suspicions are also short-lived. You can avoid any arguments with your father when he expresses his suspicions and picks up a quarrel. He can also be distracted at this time if possible, by raising some other common or neutral topic. It can help in avoiding arguments. If it fails you can temporarily leave the place after ensuring there is no possibility of his harming himself.

2) BPSD are likely to increase when there is sudden change in situation (such as travel to someone's place, or presence of guests for an evening). You can reduce the impact by announcing in advance and repeatedly reminding him that guests will be coming to meet him. If he gets agitated when the guests arrive, you can let him be in his own room and avoid the stimulation caused by the social interactions.

3) Repeated checking of his memory by questions may also cause irritability. This may not be done by you or immediate family members, but more by guests. Again, giving him the answers directly instead of testing his memory can prevent 'catastrophic reactions' as they are called.