Although no formal drug interaction studies have been performed, tiotropium bromide has been used concomitantly with other drugs commonly used in the treatment of COPD and asthma, including sympathomimetic bronchodilators, methylxanthines, oral and inhaled steroids, antihistamines, mucolytics, leukotriene modifiers, cromones and anti-IgE treatment without clinical evidence of drug interactions.
Common concomitant medications (LABA, ICS and their combinations) used by patients with COPD were not found to alter the exposure to tiotropium.
The co-administration of tiotropium bromide with other anticholinergic containing drugs has not been studied and therefore is not recommended.