Patients should not take Pelargonium sidoides if they have an allergy to this herbal preparation or allergy to a similar plant family.
For more specific information on Pelargonium sidoides, (also known as South African Geranium, Umckaloabo, Kaloba, Umcka, and Zucol) please see that section.
A small study with10 human subjects showed that theobromine (a bitter compound closely related to caffeine available in dark chocolate) at a dose of 1000 mg stopped capsaicin-induced cough better than 60 mg of codeine (5). According to Simons FE et al, the effect of theobromine peaked at 2 hours and lasted for 6 hours which was comparable to the duration and bronchodilation action of theophylline currently used as a pharmaceutical therapy for asthma (6).