This will depend on what other drugs that your grandfather is on. This med works on the brain functioning so two common side effects are nervousness and insomnia. Some other common side effects are blurred vision,increase sweating,weakness, dry mouth,headache,upset stomach with stomach problems watch for weight loss.
I wouldn't give someone with dementia effexor. I was on it for other reasons and I thought I was going to go crazier. I kept forgetting things along with balance problems. I would think that would make it worse for someone with dementia. I would advise a different medicine.
The effects of Effexor (venlafaxine) on someone with dementia are likely to be a more positive mood and a reduction in irregular behavior. There may be side undesired side effects.
Effexor is an anti-depressant drug that has a good reputation in the treatment of elderly patients with dementia. The reason for this is that it has very few side effects in comparison with most other anti-depressant drugs.
You should consult a physician or pharmacist for appropriate answers regarding effects or side effects of any medication. The drug manufacturer's website may also provide prescribing information to you if it was not given to you at the pharmacy. As with any drug, follow your physician's and pharmacist's directions for safe administration.
If you are the authorized representative for your grandfather's medical care, discuss any concerns about the medication effexor and its relation to dementia with your grandfather's treating physician.