Antacids and tigecycline, a antibiotic used to treat various bacterial infections, are not known to have a direct chemical interaction. Antacids work by neutralizing stomach acid, thereby increasing the pH level in the stomach [1]. Tigecycline, on the other hand, is a stable compound and its absorption is not significantly affected by pH changes [2].

However, antacids can potentially impact the absorption of tigecycline indirectly. Antacids can bind to other medications, forming a complex that prevents the absorption of the medication in the gastrointestinal tract [3]. This is known as a chelation reaction. However, this interaction is not specifically documented for tigecycline and antacids [2].

It is always recommended to consult with a healthcare provider or pharmacist for specific drug interaction questions and concerns [4]. They can provide the most accurate and up-to-date information based on the patient's individual medical history and current medications.

Sources:
[1] Mayo Clinic. (2021). Antacids. Retrieved from https://www.mayoclinic.org/tests-procedures/antacids/about/pac-20393563
[2] Tygacil (tigecycline) [prescribing information]. Pfizer Labs Div Pfizer Inc. 2015 Aug. Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2015/021827s017lbl.pdf
[3] National Institute on Aging. (2021). Mixing Medications and Food. Retrieved from https://www.nia.nih.gov/health/mixing-medications-and-food
[4] DrugPatentWatch. (2021). Tigecycline. Retrieved from https://www.drugpatentwatch.com/drugs/tigecycline