Medications are prescribed to control the symptoms you experience. As each person responds differently to any medication, how effective they will be will depend upon how your body and chemical balance responds.
Some symptoms tend to respond well to particular medications, for example Sinemet and Madopar may help with stiffness and slowness of movement, whilst anticholinergics may improve tremor. You will need to monitor your responses with your doctor to see what works best for you.
If you experience a number of symptoms, your doctor may prescribe more than one medication. Sometimes a medication that improves one symptom may result in another being less well controlled, so by working with your doctor you will be able to achieve a good balance of symptom control throughout the day.