Chocolate also contains the chemical theobromine, which is poisonous to dogs.
The level of capsaicin needed to cause coughing was about one third higher in the volunteers who had been given theobromine compared with placebo.
No. The volunteers who took theobromine had none of the side-effects normally caused by other cough medicines.
There is additional information about caffeine which is also generally true for its relatives theobromine and theophylline.
The other methylxanthines (the major two being theobromine and theophylline) have similar but slightly differing effects and strengths from caffeine.