Felodipine: what it treats, how to take it, side effects
Last updated September 3, 2026.
Felodipine is a calcium channel blocker - it relaxes blood vessels so pressure comes down. The extended-release tablet, once a day - and it comes with two specifics most people never hear: grapefruit, and your gums.
What does it treat?
High blood pressure, alone or with other medications.
How do you take it?
One extended-release tablet once a day, same time daily - swallowed whole, never split, chewed, or crushed: the shell is the release system. Grapefruit and grapefruit juice raise the drug level - the grapefruit conversation with your doctor is the rule. It controls blood pressure; it does not cure it - keep taking it even when you feel fine. Missed dose: take it when you remember unless the next one is close; never double up.
Side effects to know
- Common: headache, flushing, dizziness or lightheadedness, weakness, fast heartbeat, heartburn, constipation, and enlargement of gum tissue around the teeth - the gum effect makes brushing and flossing part of the treatment.
- Serious - call your doctor immediately: swelling of the face, eyes, lips, tongue, arms, or legs; difficulty breathing or swallowing; fainting; and rash.
Who should not take it?
Flag heart failure, liver disease, and every medication you take - interactions are real on this one. Dizziness on standing early: rise slowly. If you become pregnant, call your doctor.
When is it an emergency?
Fainting, face or throat swelling, or trouble breathing is a 911 call. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
What a Pymander AI doctor consult looks like
Illustrative example, not a real member's messages.
Common questions
Why no grapefruit?
Grapefruit blocks the enzyme that clears felodipine - the level in your blood can climb well past the intended dose, and the dizziness and flushing climb with it. The label directs a specific conversation with your doctor about grapefruit and its juice. The simple version most people adopt: grapefruit off the menu for the duration.
What is this about my gums?
On the label: enlargement of gum tissue around teeth - the calcium-channel-blocker class effect. The counters are unglamorous and effective: thorough brushing, daily flossing, and regular dental cleanings, plus a mention to your dentist that you take it. Caught early, it is managed in the chair; ignored, it can need more. The flossing habit is literally part of this prescription.
Why can't I split or crush the tablet?
The extended-release shell meters the day's dose across 24 hours - break it and the whole dose lands at once: blood pressure drops hard, dizziness follows. Whole, once a day, same time. Trouble swallowing is a pharmacy conversation - there are options that do not involve breaking the design.
Why do I flush and feel my heart race at first?
Vessels relaxing is the mechanism - and the face flushing, warmth, and fast heartbeat of the first days are the body noticing the change before it adapts. Usually gone within the first week or two. Flushing that persists, worsens, or comes with chest pain or fainting is a call, not a wait.
Why take it every day when I feel fine?
High blood pressure damages silently - heart, brain, kidneys - while you feel fine. The pill controls the pressure; it does not cure the tendency. Feeling fine is the drug working. Stopping means the pressure returns without announcing itself. The daily anchor is the whole treatment in one habit.
What happens if I miss a dose of felodipine?
Take it as soon as you remember, unless it is almost time for the next one - then skip it and never double up: doubling an extended-release tablet stacks a full day's release into an already-covered day. One missed day barely moves the week; the morning anchor keeps the question rare.