Caffeine is an analgesic adjuvant for paracetamol,2-4
The *analgesic adjuvant effects of caffeine are proposed to result from several mechanisms:8,9
- Blockade of the peripheral pronociceptive actions of adenosine
- Activation of central noradrenergic pathways that constitute an endogenous pain suppressing system
- Central nervous system stimulation with a consequent modulation of the affective component of pain
*A minimum concentration of 65mg caffeine in a single dose is required to have a statistically significant adjuvant effect.
Panadol Cold & Flu formulations contain 25mg per single dose. Coffee and tea have an estimated caffeine content of 0 – 96mg/237ml and 2-47mg/237ml respectively depending on the variant.
Caffeine enhances the analgesic effect of paracetamol4
Increases the effectiveness of paracetamol
Paracetamol-caffeine combinations have been shown to provide superior pain relief compared to paracetamol alone.4
After oral administration, caffeine is completely and rapidly absorbed from the gastrointestinal tract with peak concentrations occurring between 5 and 120 minutes depending on the dose, health status, and co-medications in fasted subjects.5
The influence of caffeine (60 mg) on the pharmacokinetic characteristics of acetaminophen (500 mg single dose) was studied in 10 healthy male human volunteers in a complete cross‐over design. High‐performance liquid chromatography (HPLC) was used to analyse serum drug concentrations.1
Caffeine caused a highly significant (p< 0.01) increase in AUC and AUMC, a significant (p<0.05) increase in Cmax, and a significant (p<0.05) decrease in clearance (Cl/F) of acetaminophen.1
Adverse reactions reported for caffeine include dizziness, headache, insomnia, restlessness, anxiety, irritability, nervousness, heart palpitation, and gastrointestinal disturbances.
Note that combining caffeine-containing medicinal products with dietary caffeine intake may increase the potential for caffeine-related adverse effects.4