The Side Effects of Drugs Annuals forms a series of volumes in which the adverse effects of drugs and adverse reactions to them are surveyed. The series supplements the contents of Meyler's Side Effects of Drugs: the International Encyclopedia of Adverse Drug Reactions and Interactions. This review of the January 2012 to June 2013 publications on drugs that act on the cerebral and peripheral circulations covers buflomedil, cilostazol, pentoxifylline, diosmin, ergot alkaloids, the triptans and inhibitors of phosphodiesterase type V. A number of systematic reviews and meta-analyses have shown that adding cilostazol to aspirin and clopidogrel is not significantly associated with increased risk of bleeding. Cilostazol may exacerbate left ventricular outflow tract obstruction in patients with pre-existing sigmoid shaped interventricular septum. A case of carbamazepine and cilostazol-induced hypersensitivity syndrome/reaction with eosinophilia and systemic symptoms was reported. Another case of pleural and pericardial effusion with pleuropericarditis possibly induced by ergotamine was reported. Observational studies demonstrated an increased risk of prematurity with dihydroergotamine. Animal studies showed an increased incidence of thyroid and liver cancer with chronic administration of gingko biloba. Acute kidney injury was reported with naftidrofuryl oxalate and sumatriptan. Serous retinal detachment was reported with tadalafil. This drug was also shown to exert detrimental effects on the testes and sperm function in animal studies.