Split and simplify the following sentence while retaining its full meaning: Pre-treatment with other anti- inflammatory medicines may result in additional or increased adverse effects and , accordingly a treatment-free period with such substances should be observed for at least 24 hours before the commencement of treatment with Onsior .
 Simplified version:
Prior treatment with other anti-inflammatory medicines may increase side effects or cause additional side effects . Therefore , a period of at least 24 hours without treatment should be observed before the start of treatment with Onsior .