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 the medical term for the sudden contraction of a muscle or group of muscles. This is a neuromuscular problem. It can happen anywhere, but is quite common in the legs. Myoclonus may be an indication of an underlying seizure disorder like epilepsy. It is characteristic of some hereditary disorders, such as lipid storage diseases. It is also commonly seen in metabolic diseases that cause an increase in urea in the bloodstream. Some drugs have side effects that cause abnormal muscle movements, including myoclonus. Alcohol and drug withdrawal also may be a cause.