From the Research
Muscle twitches can begin within 1-2 hours after consuming 1000mg of caffeine, which is a very high and potentially dangerous dose. This timeframe corresponds to when caffeine reaches peak blood concentration and starts to cause significant adverse effects. At this excessive dose, caffeine overstimulates the central nervous system by blocking adenosine receptors and increasing the release of excitatory neurotransmitters like dopamine and norepinephrine, as seen in a case report of a 20-year-old woman who presented with severe agitation, tremor, and vomiting approximately 1-2 h after suicidal ingestion of concentrated caffeine 1. This neural hyperactivity can cause muscle twitching, tremors, heart palpitations, anxiety, and in severe cases, seizures or cardiac arrhythmias. It's essential to note that 1000mg of caffeine exceeds the FDA's recommended safe daily limit of 400mg for healthy adults and could constitute caffeine toxicity requiring medical attention. Individual sensitivity varies based on body weight, metabolism, and caffeine tolerance, but most people would experience adverse effects at this dose, as highlighted in a study of fatal caffeine overdoses where the cause of death was ruled as caffeine intoxication and the manner of death was accidental 2. If you've consumed this amount and are experiencing symptoms, seek medical help immediately, as prompt treatment can help prevent severe complications, such as those reported in cases of nonfatal and fatal intoxications with pure caffeine 3. Key points to consider include:
- The risk of severe and even fatal poisoning is higher with pure caffeine compared to food products and non-prescription medicines containing low doses of caffeine
- Hemodialysis can be an effective treatment for severe caffeine intoxication, as seen in a case where a patient was treated using hemodialysis, which caused a rapid decrease in blood levels of caffeine and relief of the clinical symptoms of poisoning 3
- Death from caffeine overdose can be sudden and due to functional mechanisms, such as cardiac arrest, emphasizing the importance of prompt medical attention 3