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.
Functional myoclonus refers to sudden jerky or shock like movements that occur as part of a functional movement disorder. Myoclonus is a symptom found in a wide range of neurological diseases as well as some normal states. Most people have had the experience of jumping or jerking as they are dropping off to sleep.