How does this medication work? What will it do for me?

July 18, 2014

nifedipine - acetylsalicylic acid (ASA) is no longer being manufactured for sale in Canada. This article is being kept available for reference purposes only. If you are using this medication, speak with your doctor or pharmacist for information about your treatment options.

This is a combination product containing 2 medications: nifedipine and acetylsalicylic acid. It is used to treat high blood pressure and angina (chest pain brought on by exercise or stress) as well as prevent heart attack and stroke.

Nifedipine belongs to the class of medications called calcium channel blockers. It works to control blood pressure and reduce the number of angina attacks by relaxing blood vessels. Acetylsalicylic acid (ASA) belongs to the class of medications called platelet aggregation inhibitors (also called antiplatelet or anticlotting agents). It works by interfering with the production of compounds in the body that cause blood clots.

Because of the antiplatelet (anticlotting) properties of ASA, it may be used under the supervision of your doctor to:

  • prevent a first non-fatal heart attack in people who are at increased risk of having a heart attack, as determined by their doctor (factors that increase your risk of heart attack include smoking, high blood pressure, high cholesterol, inactive lifestyle, stress, and being overweight)
  • prevent a second heart attack or stroke
  • reduce the risk of "mini-stroke" or transient ischemic attack (TIA)

Nifedipine - acetylsalicylic acid is used by people who require treatment with both nifedipine and acetylsalicylic acid.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

Adalat XL Plus is no longer being manufactured for sale in Canada and is no longer available under any brand names. This article is being kept available for reference purposes only. If you are using this medication, speak with your doctor or pharmacist for information about your treatment options.

How should I use this medication?

This product combines 2 medications (nifedipine extended release and ASA) into a single package. It is prescribed for people who are already taking both nifedipine extended release and ASA, and who may find it more convenient to have both medications in a single package.

The recommended dose of extended release nifedipine tablets ranges from 20 mg to 90 mg once daily. The dose you take will depend on the dose of the individual medications that you have already been taking. The maximum recommended daily dose is 90 mg. The recommended dose of ASA for adults is one tablet (81 mg) once daily.

Each package contains tablets of nifedipine extended release and tablets of ASA that are to be taken at the same time each day. These medications should be swallowed whole and should not be chewed or broken (divided). They should be taken after meals with plenty of liquid.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not use nifedipine - acetylsalicylic acid (ASA) if you:

  • are allergic to nifedipine, acetylsalicylic acid (ASA), or any ingredients of the medication
  • are allergic to other medications of the same class as nifedipine (e.g., amlodipine, felodipine)
  • are breast-feeding
  • are pregnant or may become pregnant
  • are prone to bleeding or have a history of blood clotting problems
  • are taking methotrexate at doses of 15 mg or more per week
  • are taking rifampicin
  • have an active peptic ulcer
  • have a Kock pouch (a pouch that is used to collect body wastes after bowel surgery)
  • have had a severe allergic or asthmatic reaction caused by salicylates, ASA, or nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., diclofenac, ibuprofen, indomethacin, naproxen)
  • have very low blood pressure or cardiovascular shock

This medication should not be given to children.

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • bleeding, tender, or swollen gums
  • constipation
  • diarrhea
  • difficulty sleeping
  • dizziness
  • drowsiness
  • dry mouth
  • fatigue
  • flushing and feeling of warmth
  • gas
  • headache
  • heartburn or indigestion
  • mild-to-moderate abdominal or stomach cramps, pain, or discomfort
  • nausea
  • skin rash
  • swelling of the ankles, feet, or lower legs
  • unusual tiredness or weakness
  • vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • bleeding, tender, or swollen gums
  • buzzing or ringing in ears
  • confusion
  • fainting
  • hearing loss
  • leg cramps
  • painful, swollen joints
  • severe nausea or vomiting
  • severe or continuing abdominal or stomach pain, cramping, or burning
  • signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
  • unusual bruising or bleeding (e.g., bruising more easily)
  • unusual tiredness or weakness
  • vision changes

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • chest pain or tightness
  • irregular or fast, pounding heartbeat
  • signs of bleeding (e.g., bloody nose, blood in urine, coughing blood, cuts that don't stop bleeding)
  • signs of stomach bleeding (e.g., bloody or black, tarry stools; or swelling of the mouth and throat)
  • symptoms of an allergic reaction (e.g., difficulty breathing, coughing, or wheezing; hives; itchy skin rash)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Alcohol: People taking acetylsalicylic acid (ASA) on a daily basis are at an increased risk of developing stomach bleeds if they drink alcohol. Avoid alcohol or limit your alcohol intake while taking ASA.

Asthma: If you have asthma, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Bleeding: ASA may increase your risk of bleeding. If you have blood clotting disorders, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Your doctor will monitor you while you are taking this medication, especially if you are also taking anticoagulant medications (e.g., warfarin). Contact your doctor immediately if you notice any signs of bleeding (e.g., bloody or black, tarry stools).

Diabetes: If you have diabetes, nifedipine or ASA may affect your control of blood sugar levels. Your doctor may ask you to test your blood sugar levels more frequently when you are taking this medication.

Fluid retention: Nifedipine may cause fluid to build up in the lower legs. If you notice any puffiness or swelling of the lower legs, ankles or feet, contact your doctor as soon as possible to rule out any complications.

Gout: If you have gout or a history of gout, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Grapefruit juice: Grapefruit juice can increase blood levels of nifedipine. Avoid drinking grapefruit juice or eating grapefruit before or while you are taking nifedipine.

Heart disease: If you have severe coronary artery disease you may have an increased risk for angina and heart attack while taking this medication. Talk to your doctor about the risks and benefits of using this medication.

Heart failure: If you have severe heart failure or aortic stenosis (narrowing of a heart valve) you may be at risk for severely low blood pressure and decreased heart function while taking this medication. If you have heart failure, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Kidney function: If you have kidney disease or reduced kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: If you have liver disease or reduced liver function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Low blood pressure: Blood pressure may occasionally drop more than expected when starting nifedipine. If you are prone to low blood pressure you should monitor your blood pressure frequently while taking nifedipine. Be alert for any lightheadedness, dizziness, or a faster-than-normal heart rate. Get up slowly when moving from a lying to an upright position. If your blood pressure drops too low, your doctor will adjust your dose or try another medication.

Stomach disorders: People with certain stomach disorders (e.g., narrowing of the gastrointestinal tract or stomach ulcers) should talk with their doctor about the risks and benefits of taking this medication

Stopping the medication: Do not stop taking this medication without checking with your doctor first. Your doctor can advise you on how to stop the medication safely.

Surgery: If you are scheduled for surgery, inform your doctor that you are taking this medication. ASA should be stopped at least one week before elective surgery because of the risk of bleeding. If you are scheduled for surgery, talk to your doctor about when you should stop taking ASA.

Pregnancy: Nifedipine may cause harm to the unborn baby and should not be used during pregnancy. If you become pregnant while taking this medication, stop taking the medication and contact your doctor immediately.

Breast-feeding: Do not breast-feed if you are taking this medication.

Children: The safety and effectiveness of nifedipine have not been established for children. Children, teenagers, and young adults should not take ASA when they have chickenpox, influenza, or flu-like illnesses, as it increases their risk for Reye's syndrome, a serious health condition that may cause liver or brain damage. This product is not recommended for children under 18 years of age.

Seniors: Seniors may be more sensitive to the side effects of nifedipine.

What other drugs could interact with this medication?

There may be an interaction between nifedipine - acetylsalicylic acid and any of the following:

  • alcohol
  • angiotensin converting enzyme (ACE) inhibitors (e.g., fosinopril, lisinopril, ramipril)
  • anticoagulants (e.g., heparin, warfarin)
  • antidiabetes medications (e.g., glimepiride, glyburide)
  • antiplatelet medications (e.g., clopidogrel, ticlopidine)
  • "azole" antifungal medications (e.g., fluconazole, itraconazole, ketoconazole)
  • benzodiazepines (e.g., diazepam, lorazepam)
  • beta-blockers (e.g., atenolol, carvedilol, metoprolol, propranolol)
  • carbamazepine
  • cimetidine
  • corticosteroids (e.g., prednisone)
  • cyclosporine
  • digoxin
  • erythromycin
  • flecainide
  • fluoxetine
  • grapefruit juice
  • HIV protease inhibitors (e.g., amprenavir, indinavir, nelfinavir, ritonavir, saquinavir)
  • imipramine
  • medications containing salicylates and acetaminophen
  • methotrexate
  • nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., diclofenac, ibuprofen, indomethacin, naproxen)
  • phenobarbital
  • phenytoin
  • phenylbutazone
  • probenecid
  • propafenone
  • quinidine
  • ranitidine
  • rifampicin
  • rifampin
  • spironolactone
  • sulfinpyrazone
  • tacrolimus
  • theophylline
  • valproic acid
  • warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.