I have been prescribed famotidine but it is not available at the moment. is it safe to take omeprazole until famotidine available which it probably will be ie is switching from omeprazole back to famotidine and vice-versa safe?

Omeprazole is expected to be a little stronger as a gastric acid suppressant as it belongs to a different class of drugs called proton pump inhibitors or PPI’s. Details about the condition being treated along with goals of treatment as well as current treatment (other drugs) will be needed for a definitive answer. Your treating doc remains your best reference for that reason.