Key takeaways
Felodipine ER (Plendil) and hydrochlorothiazide are both used to treat high blood pressure, but they work in different ways and belong to different drug classes. Felodipine ER is a calcium channel blocker that relaxes blood vessels to lower blood pressure and is typically taken once daily. In contrast, hydrochlorothiazide is a diuretic (water pill) that helps you urinate more to remove extra fluid and certain electrolytes, which also lowers blood pressure. Hydrochlorothiazide can be taken once or twice daily, depending on the condition being treated. Felodipine ER is not recommended for people with heart failure, while hydrochlorothiazide must be used with caution in people with severe kidney or liver problems. Common side effects of felodipine ER include swelling, headache, and flushing, whereas hydrochlorothiazide commonly causes dizziness, increased urination, and sensitivity to sunlight. Both medications are available as lower-cost generics, but felodipine ER should not be cut or split due to its extended-release formulation.
