Why the Body Shakes During Anxiety. Shaking is a result of an activated fight or flight system - an evolutionary tool that's meant to keep you safe in times of danger. During intense anxiety, your body is flooded with adrenaline/epinephrine. Adrenaline is pure energy, and your body shakes as a result.
Your doctor may start you on a low dose of oxybutynin and gradually increase your dose. You may notice some improvement in your symptoms within the first two weeks of treatment. However, it may take six to eight weeks to experience the full benefit of oxybutynin. Talk to your doctor if your symptoms do not improve at all within eight weeks.
The time within which withdrawal symptoms may start can depend on the formulation of the drug, method in wich was taken, and individual metabolism function. Immediate-release Oxycodone, have a half-life of 3-4 hours, while extended-release forms have a longer half-life of around 12 hours.