Patient Leaflet Updated 05-Oct-2026 | Tillomed Laboratories Ltd
Flecainide acetate 50 mg and 100 mg tablets
Flecainide acetate 50mg and 100mg Tablets
1. What Flecainide is and what it is used for
2. What you need to know before you take Flecainide
3. How to take Flecainide
4. Possible side effects
5. How to store Flecainide
6. Contents of the pack and other information
Flecainide belongs to a group of medicines called anti-arrhythmics. Anti-arrhythmics work by correcting irregular heartbeats to a normal rhythm.
Flecainide is used to treat:
Talk to your doctor or pharmacist before taking Flecainide:
Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines, including medicines obtained without a prescription. This includes herbal medicines.
Dairy products like milk, infant formula and possibly yoghurt have been shown to reduce the absorption of flecainide acetate in children and infants. It is not known if this may apply to adults. Talk to your doctor or pharmacist for advice.
If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.
Flecainide should not be given to pregnant or breast-feeding mothers unless the benefits to the mother outweigh the risks to the baby. If your doctor does decide to give you flecainide, you will be monitored closely during your pregnancy.
Do not drive or operate machinery if you feel dizzy or drowsy, or you have eyesight problems while taking this medicine..
This medicine contains less than 1 mmol sodium (23 mg) per tablet, that is to say essentially ‘sodium-free’.
Your doctor will choose the dose which best suits your condition.
Supraventricular arrhythmias (irregular heartbeat that starts in the upper chambers of your heart)
Ventricular arrhythmias (irregular heartbeat that starts in the lower chambers of your heart)
When your condition has been brought under control your doctor may reduce your dose to the lowest dose you need.
Your doctor may wish to start flecainide treatment in hospital where they will perform regular ECGs (electrical tracing of the heart) and monitor your blood flecainide levels. Your doctor may also wish to perform these tests if or when they alter the dose of flecainide you are taking or if you have switched from a different formulation (e.g. from an injection of flecainide).
Your doctor may give you a lower dose and will closely monitor you.
If you have a pacemaker your dose should not exceed 100 mg twice daily. Your doctor will closely monitor you.
If you are elderly, your doctor may prescribe a lower starting dose for you.
Flecainide is not recommended for use in children under 12 years of age.
If you accidentally take too many tablets, contact your doctor or nearest hospital emergency department immediately for advice. Remember to take this leaflet or any remaining tablets with you.
Take it as soon as you remember, unless it is nearly time for your next dose. If you miss a dose, do not take a double dose to make up for a forgotten dose.
Do not stop taking Flecainide tablets without first talking to your doctor. If you suddenly stop taking flecainide you may experience side effects.
If you have any further questions on the use of this medicine, ask your doctor or pharmacist.
Like all medicines, this medicine can cause side effects, although not everybody gets them.
Common side effects (may affect up to 1 in 10 people):
Rare side effects (may affect up to 1 in 1,000 people):
Very rare side effects (may affect up to 1 in 10,000 people):
Not known (frequency cannot be estimated from the available data):
Very common side effects (may affect more than 1 in 10 people):
Common side effects (may affect up to 1 in 10 people):
Uncommon side effects (may affect up to 1 in 100 people):
Rare side effects (may affect up to 1 in 1,000 people):
Very rare side effects (may affect up to 1 in 10,000 people):
Not known (frequency cannot be estimated from the available data):
If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App store. By reporting side effects, you can help provide more information on the safety of this medicine.
Flecainide 50 mg are white to off-white, round, biconvex tablets, approximately 6.5 mm in diameter, debossed with “HP” on one side and “183” on the other side.
The 50 mg tablets are available in blister packs of 20, 30, 50, 60 or 100 tablets.
Flecainide 100 mg are white to off-white, round, curved tablets, approximately 8.5 mm in diameter, debossed with a snap-type break line separating 'H' and 'P' on one side and convex tablet debossed with '184' on other side.
The 100 mg tablets are available in blister packs of 20, 50, 60 or 100 tablets.
Not all pack sizes may be marketed.
This leaflet was last revised in 09/2026
220 Butterfield, Great Marlings, Luton, LU2 8DL, UK
+44 (0)1480 402 400 [option 2]
+44 (0)1480 402 400 [option 1]
http://www.tillomed.com/
+44 (0)1480 402 400
+44 (0)1480 402 400 [option 1]