Calan, CoveraHS, IsoptinSR, Verelan are trademarks of medicinal verapamil, which is used to treat high blood pressure and control angina.
A tablet with immediate release of this drug is also used to prevent and treat irregular heartbeats (arrhythmias).
Although this medication is not approved by the FDA for migraines, it is often prescribed to prevent it.
Verapamil is a class of drugs called calcium channel blockers. It relaxes the blood vessels, so the heart does not work so much, increasing the supply of blood and oxygen to the heart and slowing the electrical activity in the heart to control the heart rate.
Verapamil was approved by the Food and Drug Administration (FDA) in 1981.
The drug is available as a tablet, a sustained-release tablet and a sustained-release capsule for oral administration and an injection solution.
Verapamil is included in the “List of Essential Medicines” of the World Health Organization, which contains a list of the most important drugs needed in the basic health care system.
This medicine controls high blood pressure, arrhythmia and angina, but does not eliminate these conditions. You should continue to take verapamil, even if you are feeling well.
Before taking verapamil, tell your doctor if you have or have ever had:
- Poor digestion
- Myastheniagravis (a condition that leads to the weakening of certain muscles)
- Heart failure
- Heart, liver or kidney disease
- Muscular dystrophy (a hereditary disease that causes muscle weakness).
You should also tell your doctor that you are taking verapamil before any type of surgery, including dental procedures.
Your doctor will probably start with a low dose of verapamil, and then gradually increase your dose.
You must observe all meetings with your doctor while taking this medicine. You need to have your blood pressure checked regularly to determine how you react to verapamil.
Pregnancy and verapamil
The safety of verapamil during pregnancy and during breastfeeding is not defined.
Verapamil side effects
You should tell your doctor if any of the following side effects is serious or does not disappear:
- Dizziness or lightheadedness
Serious side effects
Verapamil can cause serious side effects. You should call your doctor immediately if you experience any of the following symptoms:
- Difficulty swallowing or breathing
- Swelling of the hands, feet, ankles, or lower limbs
- Blurred vision
- Slow heartbeat
- Rashes on the skin
- Extreme fatigue
- Unusual bleeding or bruising
- Lack of energy
- Loss of appetite
- Pain in the upper right side of the stomach
- Symptoms of influenza
- Yellowing of the skin or eyes (jaundice)
Interaction of verapamil
You must inform your doctor about all prescription, non-prescription, illegal, recreational, herbal, food or dietary preparations that you take, especially:
- St. John’s Wort
- Alpha blockers, such as Prazosin (Minipress)
- Antifungal agents, such as itraconazole (sporanok) and ketoconazole (Nizoral)
- Beta-blockers, such as atenolol (Tenormin), metoprolol (Lopressor, Toprol XL), nadolol (Corgard), propranolol (Inderal) and timolol (Betimol, Istalol, Timoptic, Cosopt)
- Carbamazepine (Tegretol)
- Cimetidine (Tagamet)
- Clarithromycin (Biaxin, Prevpac)
- Ciclosporin (Neoral, Sandimmune)
- Digoxin (lanoxin, lanoxicapa)
- Disopyramide (Norpace)
- Erythromycin (EES, E-Mycin, Erythrocin)
- Flecainide (Tambocor)
- Some HIV protease inhibitors, such as indinavir (Crixivan), nelfinavir (Viracept), and ritonavir (Norvir, Kaletra)
- Quinaglute (Quinidex)
- Lithium (Eskalith, Lithobid)
- Drugs to treat high blood pressure
- Nefazodone (Dutonin)
- Rifampin (Rifadine, Rimatan)
- Telithromycin (Ketek)
- Theophylline (Theolair, Uniphyl)
Other interactions of verapamil
Verapamil can change your reaction to alcohol, causing stronger and longer-lasting effects.
You should also talk to your doctor about consuming grapefruit or grapefruit juice when taking this medication.
The dose of Verapamil
For the Angina:
Compositions immediate release: initially 80-120 mg (mg), three to four times a day. The dose can be increased to 480 mg per day for several doses.
Compositions with sustained release: initially 180 mg once a day before bedtime. The dose can be increased to – 540 mg before bedtime.
Composition immediate release: Initially 80 mg three times a day. The dose may be increased to 480 mg per day, although doses greater than 360 mg do not provide any additional benefit.
Compositions with sustained release: initially 180-240 mg once a day. The dose can be increased to 240 mg, twice a day.
Direct release formulations: Initially, 80 mg three times a day. Higher doses were also used.
Overdose of verapamil
If you suspect an overdose, immediately contact a poison control center or an emergency room.
If you miss a dose of verapamil, take it as soon as you remember.
However, if there is an almost full duration of the next dose, skip the missed dose and continue your regular schedule.
Do not “double” the dose to make up for the missed one.