Valium oral tablets can slow down your brain activity and affect your judgment, thinking, and motor skills. Reasons why Valium is good for sleep. Valium also slows brain activity when you take diazepam. Also, you should not drive, operate machinery, or do any other job that requires alertness until you know how this drug affects you. There are other effects to be aware of. First, Valium is primarily used to treat anxiety. Also, Valium can cause insomnia. Don't forget panic attacks. And the symptoms of acute alcohol withdrawal. Valium tablets are considered oral medications. It should be taken orally. Therefore, it is recommended to follow the doctor's instructions. This will avoid an overdose. Again, if the dosage is increased, a doctor should be consulted. Valium Diazepam 5 mg dosage to help.