When you start or stop taking Harvoni, your doctor may need to adjust the doses of any other medicines you take on a regular basis.
If you also take an antacid: Wait at least 4 hours after taking the antacid before you take ledipasvir and sofosbuvir.
If you also take a stomach acid reducer: You may need to wait 12 hours after taking the stomach acid medicine before you take ledipasvir and sofosbuvir. This includes cimetidine, famotidine, nizatidine, ranitidine, Axid, Pepcid, Tagamet, Zantac, and others.
Ask a doctor or pharmacist before taking certain other stomach acid reducers such as esomeprazole, lansoprazole, omeprazole, pantoprazole Nexium, Prevacid, Prilosec, Protonix, and others.
Many drugs can interact with ledipasvir and sofosbuvir. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.
 Harvoni drug interactions (more detail)
