From the Guidelines
Yes, 600mg of caffeine can cause muscle twitching, as it exceeds the recommended daily limit and can lead to increased neuromuscular excitability. This dose is significantly higher than the moderate coffee consumption suggested by the DGA, which is three to five 8-oz servings per day or approximately 400 mg caffeine/d 1. Caffeine's stimulatory effects on the central nervous system can increase the release of neurotransmitters like dopamine and norepinephrine, potentially leading to involuntary muscle contractions or twitches. Key factors to consider include:
- The individual's body weight, as high caffeine intakes (e.g., >5 mg · kg body weight–1 · d–1) are associated with an increased risk of anxiety and withdrawal symptoms 1
- Metabolism, as children and adolescents metabolize caffeine more rapidly than adults 1
- Caffeine tolerance, which can influence the severity of symptoms experienced at high doses Other symptoms that might accompany muscle twitching at this caffeine level include:
- Anxiety
- Rapid heartbeat
- Insomnia
- Digestive issues
- Headaches It is essential to note that the effects of caffeine can vary widely among individuals, and some may experience more severe symptoms than others. Reducing caffeine intake is advisable if muscle twitching or other adverse effects occur. The effects should subside as the caffeine is metabolized, typically within 4-6 hours, though this varies based on individual factors 1.
From the FDA Drug Label
Signs and symptoms reported in the literature after caffeine overdose in preterm infants include ... fine tremor of the extremities, hypertonia, opisthotonos, tonic-clonic movements, One case of caffeine citrate overdose (from New Zealand) of an estimated 600 mg caffeine citrate (approximately 322 mg/kg) administered over 40 minutes was complicated by ...
Muscle Twitching can be associated with fine tremor of the extremities, hypertonia, tonic-clonic movements. A dose of 600mg caffeine is considered an overdose and has been reported to cause symptoms that may include muscle twitching, as evidenced by the symptoms of fine tremor, hypertonia, and tonic-clonic movements. 2
From the Research
Caffeine and Muscle Twitching
- Caffeine can cause muscle twitching due to its effects on calcium release from the sarcoplasmic reticulum 3, 4, 5.
- Studies have shown that caffeine can potentiate twitch responses in both fast-twitch and slow-twitch muscles, with the soleus muscle being more sensitive to caffeine's effects 3.
- The mechanism of caffeine's effect on muscle twitching is thought to involve the increase of calcium release from the sarcoplasmic reticulum, which can lead to an increase in muscle contraction force 3, 4.
Dose-Response Relationship
- The dose-response relationship between caffeine and muscle twitching is not fully understood, but studies suggest that low to moderate doses of caffeine (0.01-2.5 mM) can potentiate twitch tension, while higher doses (20 mM) can lead to maximal contractures 6.
- A dose of 600mg of caffeine is equivalent to approximately 2-3 mM, which is within the range that can potentiate twitch tension in some studies 6.
Individual Variability
- Individual variability in response to caffeine's effects on muscle twitching is likely due to differences in muscle fiber type, caffeine sensitivity, and other factors 7.
- More research is needed to fully understand the relationship between caffeine dose and muscle twitching, as well as the individual factors that influence this response.