Learning objectives Reading this article will reinforce the reader's awareness of the adverse effects of medications used for the treatment of rhinitis. Data sources Articles on therapy of rhinitis and reports of associated side effects were reviewed. A MEDLINE database using subject keywords was searched from 1992 through 1997. Study selection Pertinent articles were chosen. A distinction was made in the text between controlled studies and case reports. Results Antihistamines, decongestants, anticholinergic agents, and corticosteroids, alone or in combination are used in the treatment of rhinitis. Reported side effects include sedation, psychosis, impaired learning and memory, and cardiac arrhythmias. Conclusion Rhinitis and its complications are important medical conditions. Adverse reactions are often difficult to diagnose and assess. Side effects may arise from the use of individual drugs or from drug combinations. There is insufficient cause to abandon these medications, but physicians must be mindful of the inherent risks of the drugs that they prescribe and of others that their patients may be taking without the physicians' knowledge or approval.