What Causes Jerking Of Hand And Leg Muscles When Lie On Bed?

usually when i lie on bed my muscles on the leg and hands start jerking. it sometimes get very annoying. and sometimes i feel tingling sensation on hands and legs especially after having lunch. today morning my thigh muscles were jerking frequently. from the past 2 months i have been observing continious hissing sound in my ears. i am taking betadoxin 12 syrup for the past 4 days.