Zemtard XL (diltiazem XL) is the extended-release version of a calcium channel blocker better known by the brand name Cardizem. Calcium channel blockers widen blood vessels, improve blood and oxygen flow to the heart, and reduce the speed and strength of individual heart beats. The end result is lower blood pressure and reduced heart strain.

This medication is most commonly used to treat:

• Mild to moderate hypertension (high blood pressure)
• Angina

Off-label it may be used to treat:

• Certain heart arrhythmias
• Cluster headaches
• Raynaud's disease/phenomenon
• Tardive dyskinesia
• Other conditions

It is thought that the medication is beneficial in all conditions due to its vasodilation properties, which improve overall blood flow. Arteries can be clogged with cholesterol, become constricted with age, or otherwise impair blood flow; Zemtard XL works to counter this and often provides significant benefit, allowing patients to retain independence, improve quality of life, and even extend life.

Getting Started

The XL in Zemtard XL indicates it's a sustained release formula, meaning it's taken just once per day. Other formulations are taken two to four times per day; this particular formula is the most convenient.

Zemtard XL comes in capsules, which must be swallowed whole. Destroying the integrity of the capsule will allow all of the medication to be released at once, ruining its XL properties and putting the patient at risk of overdose. Patients who have difficulty swallowing whole tablets should speak with a doctor about alternative options.

Capsules may be taken with or without food according to personal preference. A glass of fluid is recommended, but not necessary.

Treatment usually consists of:

• Patients are typically started on 240, taken once per day.
• Capsules should be taken at the same time each day.
• Results should be evaluated after 14 days; dosage may be increased or decreased depending on patient response and tolerance to side effects.
• Most patients find 180 mg to 300 mg effective.
• Hypertension patients will usually be given another hypertension medication rather than increasing Zemtard XL dosage over 360 mg per day.
• Angina patients should not exceed 480 mg per day.
• Off-label conditions are highly variable; doctor instructions should be followed.

Patients who experience serious or disruptive side effects at the starting dose of 240 mg may have dosage reduced. Those who have other medical conditions or take other medications that put patients at increased risk of side effects are typically started at lower doses, usually 120 mg.

Angina patients should have fewer angina episodes. Some lucky patients won't have episodes at all while taking Zemtard XL, but many do still have them, just less frequently. Zemtard XL will not address a current episode; patients are usually prescribed a fast-acting rescue treatment to have on hand if needed.

Both hypertension and angina patients are usually encouraged to address the underlying issue by making and maintaining lifestyle changes, such as adopting an exercise regimen and dietary changes. In the majority of cases this is the only way to permanently address the underlying issue and stop relying on medications.

Patients who stop taking Zemtard XL abruptly may experience withdrawal effects. If the time comes to end treatment, speak with a doctor about a discontinuation plan.

Before Taking Zemtard XL

There are some other medical conditions that put patients at increased risk of serious complications when Zemtard XL is taken, namely:

• Sick sinus syndrome
• Severe bradycardia (slow heartbeat)
• Heart failure
• Left ventricular failure
• Atrioventricular block
• Kidney or liver impairment

And other medications known to interact with Zemtard XL include:

• Digoxin
• Cimitidine
• Azole antifungals
• Macrolide antibiotics
• Benzodiapines
• Rifamycins
• St. John's wort
• Aprepitant
• Buspirone
• Ivabradine
• Cold or flu medications
• NSAIDs

All calcium channel blockers will lower blood pressure and slow heart rate, regardless of what they're taken to treat. Any medical condition or medications that reduce blood pressure and/or influence heart rate have the potential to cause serious complications and should be brought to the attention of the prescribing doctor

Don't be afraid to ask questions or bring up concerns, no matter how trivial they may seem.