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.
Myoclonus is a leading sign of other nervous system disorders including Parkinsonâs disease, Alzheimerâs, multiple sclerosis and epilepsy. Myoclonus is caused by sudden jerks or contractions in the muscles, and also of the muscles uncontracting or relaxing after contraction.