Severe hypersensitivity reactions (HSRs) to anticancer drugs often make it difficult to continue treatment, especially in paclitaxel, even when treated with prophylactic medication. The authors of this book analysed severe HSRs incidence in patients treated with modified premedication protocol and historically compared to that using standard premedication before 2004. It was found that the modified premedication protocol could successfully reduce the incidence of severe HSRs in patients treated with paclitaxel. Furthermore, substandard and faked formulations are a global burden of virtually all countries. The collapse of the former Soviet Union (FSU) in the nineties lead to the retardation of the formerly remarkable pharmaceutical industry and drug quality control system of FSU. This book describes the pharmacopoeial quality of three EU registered and three Russian Federation registered aciclovir formulations. The data indicates that the pharmacopoeial quality of the antimicrobial and antiviral formulations from the Russian Federation drug market is similar to the European competitors. Other chapters in this book evaluate bioequivalence in order to establish the interchangeability of generic drugs, describe the most important aspects of the cholinergic neurotransmission, as well as natural and synthetic compounds that are able to influence it as therapeutic or experimental drugs. The authors also provide a comprehensive overview of the clinical and practical aspects of corticosteroids-induced delayed hypersensitivity and its consequences on anti-inflammatory therapeutic choices.