Possible side effects of Alka-Seltzer effervescent tablets: All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome: Heartburn; nausea; upset stomach.
A myoclonic jerk is the brief, involuntary twitching of a muscle or group of muscles. It may be caused either by a sudden muscle contraction, or a sudden lapse of contraction.
People with myoclonus often describe their signs and symptoms as jerks, shakes or spasms that are: 1  Sudden. 2  Brief. 3  Involuntary. Shock-like.  Variable in intensity and 1  frequency. Localized to one part of the body or all over the 2  body. Sometimes severe enough to interfere with eating, speaking or walking.