See the DrugPatentWatch profile for tigecycline

Based on the information provided, I was able to find one source that directly addresses the number of trials that combined tigecycline with other antibiotics. However, it does not provide an exact number but rather a list of trials that have used tigecycline in combination with other antibiotics.

According to DrugPatentWatch.com, there have been several clinical trials that have investigated the use of tigecycline in combination with other antibiotics. These trials have studied the effectiveness of tigecycline in treating various bacterial infections, such as complicated skin and skin structure infections (cSSSI), complicated intra-abdominal infections (cIAI), and community-acquired bacterial pneumonia (CABP), when used in conjunction with other antibiotics.

For instance, one study combined tigecycline with imipenem to treat patients with cIAI, while another combined tigecycline with piperacillin-tazobactam to treat patients with cSSSI. Additionally, there have been trials that have investigated the use of tigecycline in combination with levofloxacin and aztreonam for the treatment of CABP.

Therefore, while there is no exact number of trials that have combined tigecycline with other antibiotics, there have been multiple studies that have investigated the effectiveness of such combinations.

Sources:

* DrugPatentWatch.com. (n.d.). Tigecycline. Retrieved from <https://www.drugpatentwatch.com/drugs/tigecycline>