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.
Nerve misfiring: One hypothesis for the hypnagogic jerks is that they are an inherent aspect of the bodyâs transition from wakefulness to sleep. This hypothesis suggests that as we transition to a sleeping state, our nerves may occasionally misfire, causing a jolting movement immediately before weâre fully asleep.