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Tiazac (Generic Diltiazem)

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Why is this medication prescribed?

Tiazac is a brand name for the drug diltiazem, which belongs to a class of medications known as calcium channel blockers. It is primarily prescribed to treat high blood pressure (hypertension), chest pain (angina), and certain heart rhythm disorders such as atrial fibrillation or atrial flutter.

How should this medicine be used?

Here’s how Tiazac is typically used:

  • Dosage: The dosage of Tiazac prescribed will vary depending on the condition being treated and individual patient factors. It’s crucial to follow the dosage instructions provided by your doctor or pharmacist.
  • Administration: Tiazac is usually taken orally in the form of extended-release capsules or tablets. The extended-release formulation allows for once-daily dosing, but again, follow your doctor’s instructions regarding the timing and frequency of dosing.
  • Swallowing: Swallow the capsules or tablets whole with a full glass of water. Do not chew, crush, or break them, as this can alter the way the medication is released in the body.
  • Consistency: Try to take Tiazac at the same time each day to maintain consistent levels of the medication in your bloodstream.
  • Food Interaction: Tiazac can be taken with or without food, but it’s essential to be consistent. If you choose to take it with food, try to take it the same way each time.
  • Monitoring: Regular monitoring of blood pressure and heart rate may be necessary while taking Tiazac to ensure it’s working effectively and to detect any potential side effects.
  • Duration: Continue taking Tiazac for as long as your doctor prescribes it, even if you start feeling better. Stopping suddenly can lead to worsening of your condition.
  • Missed Dose: If you miss a dose of Tiazac, take it as soon as you remember. However, if it’s close to the time of your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Do not double up on doses to make up for a missed one.
  • Caution: Avoid consuming grapefruit or grapefruit juice while taking Tiazac, as it can interact with the medication and lead to potentially dangerous side effects.

It’s crucial to communicate with your doctor or pharmacist if you have any questions or concerns about how to use Tiazac properly. They can provide personalized guidance based on your medical history and current health status.

Other uses for this medicine

Other uses for Tiazac (diltiazem) may include:

  • Treatment of certain types of abnormal heart rhythms (arrhythmias): Diltiazem can help control the heart rate in conditions such as atrial fibrillation or atrial flutter.
  • Migraine prevention: Some studies suggest that diltiazem may be effective in preventing certain types of migraines.

What special precautions should I follow?

Special precautions to consider when taking Tiazac (diltiazem) include:

  • Allergies: Inform your doctor if you have any allergies to diltiazem or any other medications. This medication may contain inactive ingredients that can cause allergic reactions or other problems.
  • Medical History: Disclose your full medical history to your doctor, especially if you have certain heart conditions, liver disease, kidney disease, certain muscle conditions (such as myasthenia gravis), or if you have a history of heart failure.
  • Pregnancy and Breastfeeding: Inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding. The safety of diltiazem during pregnancy and breastfeeding is not well established, and your doctor will need to weigh the potential risks and benefits before prescribing it.
  • Interactions: Diltiazem can interact with other medications, including certain antibiotics, antifungals, HIV medications, and others. Make sure your doctor is aware of all the medications, supplements, and herbal products you are taking to avoid potentially harmful interactions.
  • Grapefruit: Avoid consuming grapefruit or grapefruit juice while taking diltiazem, as it can increase the levels of the medication in your bloodstream and lead to potentially serious side effects.
  • Dizziness: Diltiazem may cause dizziness or lightheadedness, especially when you first start taking it or when the dosage is adjusted. Avoid driving or operating machinery until you know how the medication affects you.

Always follow your doctor’s instructions and ask any questions you may have about the precautions associated with taking Tiazac (diltiazem).

What special dietary instructions should I follow?

There are no specific dietary restrictions associated with Tiazac (diltiazem). However, it’s generally recommended to maintain a healthy, balanced diet while taking this medication. It’s essential to follow any dietary recommendations provided by your doctor or healthcare provider, especially if you have other medical conditions such as high blood pressure or heart disease.

What should I do if I forget a dose?

If you forget a dose of Tiazac (diltiazem), take it as soon as you remember. However, if it’s close to the time of your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Do not double up on doses to make up for a missed one. If you have any concerns or questions about missed doses, consult your doctor or pharmacist for guidance.

What side effects can this medication cause?

Tiazac (diltiazem) can cause various side effects, although not everyone experiences them. Common side effects may include:

  • Dizziness or lightheadedness: Especially when standing up quickly from a sitting or lying position.
  • Headache: Some individuals may experience headaches while taking Tiazac.
  • Flushing: A feeling of warmth or redness in the face or skin.
  • Nausea or upset stomach: Some people may experience gastrointestinal discomfort.
  • Constipation: Tiazac can sometimes cause constipation as a side effect.
  • Fatigue or tiredness: Feeling more tired than usual is a common side effect.
  • Swelling of ankles or feet: Some individuals may experience swelling in the lower extremities.
  • Rash or itching: Skin reactions such as rash or itching may occur in some cases.
  • Palpitations: Some people may experience irregular heartbeats or palpitations.
  • Low blood pressure: In some cases, Tiazac may cause a drop in blood pressure, leading to symptoms such as dizziness or fainting.

Less common but potentially more serious side effects of Tiazac may include:

  • Bradycardia: A slower than normal heartbeat, which can cause symptoms such as dizziness, fainting, or shortness of breath.
  • Heart block: A condition where the electrical signals in the heart are delayed or blocked, leading to symptoms such as dizziness, fainting, or chest pain.
  • Liver problems: In rare cases, Tiazac can cause liver damage or hepatitis.
  • Allergic reactions: Some individuals may experience severe allergic reactions to diltiazem, including rash, itching, swelling of the face, tongue, or throat, severe dizziness, or trouble breathing.

If you experience any severe or persistent side effects while taking Tiazac, it’s important to contact your doctor or seek medical attention promptly. Additionally, if you have any concerns about potential side effects, talk to your doctor or pharmacist for further guidance.

What should I know about storage and disposal of this medication?

Storage and disposal:


  • Store Tiazac at room temperature away from moisture, heat, and light.
  • Keep the medication in its original packaging or container, tightly closed, and out of reach of children and pets.
  • Do not store Tiazac in the bathroom, as moisture and humidity can affect its effectiveness.
  • Avoid exposing Tiazac to extreme temperatures, such as freezing or excessive heat.


  • Dispose of any unused or expired Tiazac properly to prevent accidental ingestion by children, pets, or others.
  • Follow any specific disposal instructions provided by your doctor, pharmacist, or local waste disposal authorities.
  • Do not flush Tiazac down the toilet or pour it down the drain unless instructed to do so by specific disposal guidelines. Instead, consider using a medication take-back program or returning it to a pharmacy for proper disposal.

In case of emergency/overdose

  • If you suspect an overdose of Tiazac or experience severe symptoms such as fainting, difficulty breathing, or irregular heartbeat, seek immediate medical attention by calling your local emergency services or going to the nearest emergency room.
  • Be prepared to provide information about the amount of Tiazac taken, as well as any other medications or substances ingested.
  • If possible, bring the medication container or packaging with you to the emergency room to assist healthcare providers in determining the appropriate treatment.

What other information should I know?

  • Keep all appointments with your doctor and laboratory while taking Tiazac to monitor your response to the medication and check for any potential side effects.
  • Avoid drinking alcohol while taking Tiazac, as it can increase the risk of side effects such as dizziness or drowsiness.
  • Inform any healthcare provider involved in your care, including dentists and surgeons, that you are taking Tiazac, as it may interact with other medications or affect certain medical procedures.
  • Follow your doctor’s instructions carefully regarding dosage, timing, and duration of treatment with Tiazac, and do not stop taking the medication without consulting your doctor first.

If you have any further questions or concerns about Tiazac, its storage, disposal, or what to do in case of emergency, consult your doctor or pharmacist for personalized guidance and advice.

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