H2-RECEPTOR ANTAGONISTS AND THEOPHYLLINE
Cimetidine raises theophylline serum levels (by about one-third) and toxicity has been seen. The interaction is unlikely to be clinically relevant in most patients with low- dose (non-prescription) cimetidine.
Monitor theophylline levels if cimetidine is added or withdrawn. The peak effect appears to occur after 3 days. Alternatively, use ranitidine or famotidine, which appear not to interact.
Monitor theophylline levels if cimetidine is added or withdrawn. The peak effect appears to occur after 3 days. Alternatively, use ranitidine or famotidine, which appear not to interact.