Why is Calan prescribed?

Verapamil is used to treat irregular heartbeats (arrhythmias) and high blood pressure. It relaxes your blood vessels so your heart does not have to pump as hard. It also increases the supply of blood and oxygen to the heart to control chest pain (angina). If taken regularly, verapamil controls chest pain, but it does not stop chest pain once it starts. Your doctor may give you a different medication to take when you have chest pain.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should Calan be used?

Verapamil comes as a regular tablet and as an extended-release (long-acting) tablet and capsule to take by mouth. The regular tablet is usually taken three times a day. The extended-release tablet and capsule are usually taken one or two times a day and should be swallowed whole. Do not chew, divide, or crush the extended-release tablet or capsule. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take verapamil exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Verapamil controls arrhythmias, high blood pressure, and chest pain (angina) but does not cure them. Continue to take verapamil even if you feel well. Do not stop taking verapamil without talking to your doctor.

What are some Calan precautions?

Before taking verapamil,

• tell your doctor and pharmacist if you are allergic to verapamil or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially aspirin, carbamazepine (Tegretol); cyclosporine (Neoral, Sandimmune); fentanyl (Duragesic); heart and blood pressure medications such as beta-blockers, digoxin (Lanoxin), disopyramide (Norpace), flecainide (Tambocor), quinidine (Quinaglute, Quinidex), diuretics ('water pills'), or any other blood pressure lowering medication; lithium (Eskalith, Lithobid); medications to treat depression; medications to treat glaucoma (increased pressure in the eye); phenobarbital; rifampin (Rifadin, Rimactane); theophylline (Theo-Dur); and vitamins.
• tell your doctor if you have or have ever had heart, liver, or kidney disease, muscular dystrophy, or gastrointestinal obstruction (strictures).
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking verapamil, call your doctor.
• if you are having surgery, including dental surgery, tell your doctor or dentist that you are taking verapamil.
• you should know that verapamil may increase the effects of alcohol and make them last longer.

What are some possible Calan side effects?

Verapamil may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• constipation
• dizziness or lightheadedness
• headache
• upset stomach
• heartburn
• excessive tiredness
• flushing (feeling of warmth)
• slow heartbeat
• vivid, unusual dreams

If you experience any of the following symptoms, call your doctor immediately:

• swelling of the face, eyes, lips, tongue, arms, or legs
• difficulty breathing or swallowing
• fainting
• rash
• yellowing of the skin or eyes
• fever
• increase in frequency or severity of chest pain (angina)

Calan SR (verapamil) is a calcium channel blocker used to treat hypertension, angina, supraventricular tachycardia, migraines, and cluster headaches. It can be used in patients age 16 and up.

The medication is thought to work by relaxing and slowing the heart, while also relaxing and dilating blood vessels, which lowers blood pressure and reduces the heart's workload. The mechanism by which it works in treating migraines and cluster headaches is not clear.

Note that the SR in this product stands for sustained release, meaning tablets need be taken just once or twice per day. Regular Calan tablets, taken two or three times per day, are available here. Calan SR tablets must be swallowed whole; regular Calan capsules can be mixed into soft foods if desired.

What to Expect from Calan SR

Calan SR may be prescribed when a person has one or more of several ailments:

• Hypertension (high blood pressure)
• Angina (chest pain)
• Supraventricular tachycardia (rapid heartbeat)
• Migraine headaches (preventative only)
• Cluster headaches (preventative only)

The medication is generally not prescribed in patients who have:

• Hypotension (low blood pressure)
• Left ventricular dysfunction in the heart
• Cardiogenic shock

The lowered heart rate and dilation of blood vessels reduce blood pressure and improve blood flow. Lowered heart rate also addresses supraventricular tachycardia, in which the heart beats too fast. Angina, typically caused by insufficient blood flow to the heart muscle, is also alleviated by the improved blood flow. While the exact mechanism behind treating migraine and cluster headaches is unclear, the medication does provide benefit in most cases.

In many conditions Calan SR treats, it is preventative---reduces the frequency and severity of angina, migraines, and cluster headaches. The medication provides little benefit if these conditions flare up; users will still need to utilize other rescue medications, such as nitroglycerin for angina or triptan medications for migraine or cluster headache pain, when they do flare up. As it takes several weeks to see the full benefit of Calan SR, having rescue treatments available will be especially beneficial at the start of treatment.

After several weeks of treatment at an appropriate dose full benefit should be seen. Blood pressure and heart rate should be lower; angina, migraines, and cluster headache frequency should be dramatically reduced, if they occur at all.

Taking Calan SR

Treatment with Calan SR is quite similar in all cases; the medication is taken daily over the long term. Other medications may or may not be involved. Personal variables, such as age and weight, can influence dosage levels, as will patient response to treatment.

In otherwise healthy adults, standard treatment is typically:

• Take 180 mg per day in the morning.
• Tablets should be swallowed whole and taken with food.

The initial dose may need to be adjusted; effects should be checked after one week of treatment for hypertension, perhaps longer---three to four weeks---for other conditions. If adjustments are needed there are several options:

• Take 240 mg once per day in the morning; or
• Take 180 mg in the morning and 180 mg in the evening; or
• Take 240 mg in the morning and 120 mg in the evening; or
• Take 240 mg every 12 hours.

Higher doses---more than 240 mg total per day---are typically reserved for heart conditions. For migraines and cluster headaches treatment is more likely 240 mg per day or less, though there may be exceptions. Patients taking Calan SR will likely need frequent heart and blood pressure tests until the ideal dosage is established, regardless of why it's being taken.

Calan SR can significantly extend and improve a patient's life by lowering blood pressure, regulating heartbeat, and reducing the frequency of angina, migraines, or cluster headaches---all of these things can have a dramatically negative impact if left untreated.