Elderly
Aging increases the risk of dysphagia. The prevalence of dysphagia in nursing homes is approximately 50%, and 30% of the elderly with dysphagia develop aspiration. For individuals older than 75, the risk of pneumonia due to dysphagia, is six times greater than those 65. Owing to multiple factors, such as frailty, impaired efficacy of swallowing, decreased cough reflex and neurological complications, dysphagia can be considered as a geriatric syndrome. Atypical presentation is common in the elderly. Older patients may have impaired T cell function and hence, they may be unable to mount a febrile response. The mucociliary clearance of older people is also impaired, resulting in diminished sputum production and cough. Therefore, they can present non-specifically with different geriatric syndromes. Microaspirations
In the elderly, dysphagia is a significant risk factor for the development of aspiration pneumonia. Aspiration pneumonia most often develops due to micro-aspiration of saliva, or bacteria carried on food and liquids, in combination with impaired host immune function. Chronic inflammation of the lungs is a key feature in aspiration pneumonia in elderly nursing home residents and presents as a sporadic fever (one day per week for several months). Radiological review shows chronic inflammation in the consolidated lung tissue, linking chronic micro-aspiration and chronic lung inflammation. Choking
After falls, choking on food presents as the second highest cause of preventable death in aged care. Although food choking risk is commonly associated with young children, data shows that individuals over 65 years of age have a choking incidence that is seven times higher than children aged 1–4 years.
Felodipine has additionally been found to act as an antagonist of the mineralocorticoid receptor, or as an antimineralocorticoid.Different calcium channels are present in vascular tissue and cardiac tissue; an in vitro study on human vascular and cardiac tissues comparing how selective various calcium channel blockers are for vascular compared to cardiac tissue found the following vascular/cardiac tissue ratios: mibefradil 41,  felodipine 12; nifedipine 7, amlodipine 5, and verapamil 0.2.: 172

Chemistry
Felodipine is a member of the 1,4-dihydropyridine class of calcium channel blockers. : 20–21   It is a racemic mixture, and is insoluble in water but is soluble in dichloromethane and ethanol. : 25

History
The Swedish company Hässle, a division of Astra AB, discovered felodipine; it filed a patent application in 1979 claiming felodipine as an antihypertensive drug. Astra partnered this drug and others with Merck & Co. in the US under a 1982 agreement between the companies. The drug was approved by the FDA in 1991 after a three and a half year review; the drug entered a very crowded market the included the other calcium channel blockers nifedipine, verapamil, nicardipine, and isradipine.