Generic Name: nifedipine
Product Name: Adalat 10, Adalat 20
Indication: What Adalat 10, Adalat 20 are used for
Adalat tablets are not used for the relief of a sudden attack of angina or to manage unstable angina.
Ask your doctor if you have any questions about why this medicine has been prescribed for you. Your doctor may have prescribed it for another reason.
Action: How Adalat 10, Adalat 20 work
Adalat tablets contain the active substance nifedipine which belongs to a group of medicines called calcium channel blockers. They work by opening up blood vessels in the body to lower blood pressure and improve the supply of blood and oxygen to the heart.
The contractile processes of vascular smooth muscle and cardiac muscle are dependent upon calcium ions. Calcium ions enter these cells during depolarisation as slow ionic transmembrane currents. Nifedipine specifically inhibits slow inward calcium ion channels without changing serum calcium concentrations. In so doing, two distinct beneficial effects are produced which reduce anginal pain in individuals with ischaemic heart disease.
Nifedipine is a potent relaxant of arterial smooth muscle. It dilates main coronary arteries and arterioles both in normal and in ischaemic myocardial regions without inducing a steal phenomenon. Nifedipine is also a potent inhibitor of coronary artery spasm. These effects increase myocardial oxygen delivery at rest and during exercise in patients with chronic stable angina, and in patients with episodes of coronary artery spasm.
As with myocardial cell contraction, regulation of the contraction of the vascular smooth muscle is also dependent upon intracellular calcium ion concentration. By reducing the influx of calcium ions into vascular smooth muscle, nifedipine causes relaxation and peripheral vasodilatation. Peripheral vasodilatation reduces the impedance (afterload) against which the heart works. This unloading of the heart indirectly reduces myocardial energy consumption and oxygen requirements. Ventricular emptying is also facilitated by the reduction in impedance.
These tablets contain the active ingredient nifedipine. Adalat 10 contains nifedipine 10 mg. Adalat 20 contains nifedipine 20 mg.
It also contains the inactive ingredients cellulose, maize starch, lactose, polysorbate 80, hypromellose, macrogol 4000, magnesium stearate, iron oxide red, and titanium dioxide.
Dose advice: How to use Adalat 10, Adalat 20
Before you take Adalat
When you must not take it
Do not take Adalat if you have an allergy to:
- Nifedipine, the active ingredient in Adalat;
- Any of the ingredients listed here.
Some of the symptoms of an allergic reaction may include:
- Shortness of breath;
- Wheezing or difficulty breathing;
- Swelling of the face, lips, tongue or other parts of the body;
- Rash, itching or hives on the skin.
Do not take Adalat if you are in cardiogenic shock (very low blood pressure due to a failing heart). Tell your doctor if you have had a heart attack in the last week or so.
Do not take Adalat tablets if you are taking another medicine containing the active substance rifampicin, an antibiotic used to treat tuberculosis and other serious infections.
Do not take this medicine if you are pregnant. It may affect your developing baby if you take it during pregnancy.
Do not breastfeed if you are taking this medicine. The active ingredient in Adalat passes into breast milk and there is a possibility that your baby may be affected.
Do not take this medicine after the expiry date printed on the pack and blister. The expiry date is printed on the carton and on each blister after “EXP” (e.g. 11 18 refers to November 2018). The expiry date refers to the last day of that month. If it has expired return it to your pharmacist for disposal.
Do not take this medicine if the packaging is torn or shows signs of tampering. If the packaging is damaged, return it to your pharmacist for disposal.
Do not take tablets that show visible signs of deterioration (e.g. are broken or discoloured).
If you are not sure whether you should start taking this medicine, talk to your doctor.
Before you start to take it
Tell your doctor if you have allergies to any other medicines, foods, preservatives or dyes.
Tell your doctor if you have or have had any of the following medical conditions:
- Heart failure;
- Other heart or blood vessel disorders;
- Low blood pressure;
- Mini-stroke (also known as TIA or transient ischaemic attack);
- Liver disease;
If you have not told your doctor about any of the above, tell them before you start taking Adalat.
Adalat contains lactose. If you have been told by your doctor that you have an intolerance to some sugars, tell your doctor before taking it.
Tell your doctor if you eat grapefruit or drink grapefruit juice regularly, including in the last 3 days before starting Adalat. You should not have grapefruit while you are taking Adalat because this can cause unwanted changes in the blood pressure lowering effect of the tablets.
Taking other medicines
Tell your doctor or pharmacist if you are taking any other medicines, including any that you get without a prescription from your pharmacy, supermarket or health food shop. Some medicines and Adalat may interfere with each other. Examples are given below but this is not a complete list. Talk to your doctor or pharmacist if you have any questions.
Medicines to be careful with or avoid while taking Adalat include:
- Beta-blockers, e.g. metoprolol, atenolol;
- Other medicines used to treat high blood pressure or angina, e.g. diltiazem;
- Medicines used to treat arrhythmia (fast or irregular heartbeats), e.g. quinidine;
- Other medicines used to treat heart disease, e.g. digoxin;
- Some medicines used to treat stomach ulcers and heartburn, e.g. cimetidine, cisapride;
- Rifampicin, used to treat tuberculosis and other serious infections;
- Other medicines used to treat bacterial infections, e.g. erythromycin, quinupristin, dalfopristin;
- Medicines used to treat fungal infections, e.g. ketoconazole;
- Medicines used to treat HIV, e.g. ritonavir;
- Medicines used to treat epilepsy, e.g. phenytoin, carbamazepine, valproic acid, phenobarbitone;
- Anti-depressants, e.g. fluoxetine, nefazodone;
- Tacrolimus, used to prevent rejection after an organ transplant.
These medicines may be affected by Adalat or may affect how well it works. You may need to take different amounts of your medicine or you may need to take different medicines.
Your doctor or pharmacist has a more complete list of medicines to avoid while taking Adalat.
How to take Adalat
Follow all directions given to you by your doctor or pharmacist carefully. They may differ from the information contained here.
If you do not understand the instructions printed on the pharmacist label, ask your doctor or pharmacist for help.
How much to take
The correct dose of Adalat to take has been decided by your doctor. Make sure you follow the instructions given to you by your doctor.
The usual dosage is 10 mg to 20 mg twice daily. Your doctor may increase the dose if required.
How to take it
Swallow the tablets whole with some liquid, either with or without a meal. Do not break or chew the tablets.
When to take it
The tablets are usually taken every 12 hours.
How long to take it
Your doctor will determine how long you should take Adalat tablets. Do not stop taking the tablets unless you are told to do so by your doctor.
If you forget to take it
If you have forgotten to take your Adalat tablet(s) at the right time, take it as soon as you remember, then continue as normal for the next dose. If you do not remember until it is almost time to take your next dose [i.e. within 6 (six) hours of your next dose], then skip the dose that you forgot but be sure to take the next dose when it is due.
Do not take a double dose to make up for the dose you missed. If you have missed several doses, consult your doctor.
If you take too much (overdose)
Immediately telephone your doctor or Poisons Information Centre for advice (Australia: 13 11 26), or go to Accident and Emergency at your nearest hospital, if you think that you or anyone else may have taken too many Adalat tablets. Do this even if there are no signs of discomfort or poisoning. You may need urgent medical attention.
Signs of an overdose include feeling dizzy and fainting due to drop in blood pressure, irregular or rapid heartbeats, shortness of breath, shock, and loss of consciousness.
While you are taking Adalat
Things you must do
Take Adalat tablets exactly as told by your doctor. If you do not follow your doctor’s instruction, you may not get control of your blood pressure or relief from your angina.
If you are about to be started on any new medicine, remind your doctor and pharmacist that you are taking Adalat.
Tell your doctor if you continue to have angina attacks or if they become more frequent while you are taking Adalat tablets.
Tell all doctors, dentists, and pharmacists who are treating you that you are taking Adalat tablets.
The use of Adalat may affect the results of certain laboratory tests. If you are about to have any tests, tell your doctor that you are taking this medicine.
If you become pregnant while taking this medicine, tell your doctor immediately.
Things you must not do
Do not give this medicine to anyone else, even if their symptoms seem similar to yours.
Do not use it to treat any other medical conditions unless your doctor tells you to.
Do not eat grapefruit or drink grapefruit juice while you are taking this medicine. Grapefruit can cause unwanted changes in the blood pressure lowering effect of Adalat.
Do not stop taking your medicine or lower the dosage without checking with your doctor. If you stop taking it suddenly, your condition may worsen or you may have unwanted side effects.
Things to be careful of
Be careful driving or operating machinery until you know how Adalat affects you. Adalat tablets may cause dizziness or fainting in some patients, especially when they first start taking the medicine, change dose, or drink alcohol.
If you have angina, be careful not to overdo physical activities when you first start taking Adalat. You may feel better when you start taking it, but you will need time to improve your physical fitness.
After taking Adalat
Keep your tablets in the pack until it is time to take them. If you take the tablets out of the pack they may not keep well.
Keep the medicine in a cool dry place where the temperature stays below 25°C. Do not store it or any other medicine in the bathroom, near a sink, or on a window-sill. Do not leave it in the car. Heat and damp can destroy some medicines.
Keep the tablets where children cannot reach them. A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.
Schedule of Adalat 10, Adalat 20
Adalat 10 and Adalat 20 are Schedule 4 (prescription only) medicines.
Side effects of Adalat 10, Adalat 20
Tell your doctor or pharmacist as soon as possible if you do not feel well while you are taking Adalat. All medicines have side effects. Sometimes they are serious, most of the time they are not. In serious cases, you may need medical attention.
Do not be alarmed by the following lists of side effects. You may not experience any of them.
Ask your doctor or pharmacist to answer any questions you may have.
Tell your doctor or pharmacist if you notice any of the following and they worry you.
The list below includes the more common side effects of your medicine. They are usually mild and short-lived.
- Feeling dizzy;
- Fast or irregular heartbeats;
- Feeling sick (nausea);
- Generally feeling unwell;
- Unusual tiredness or weakness;
- General swelling and/or swelling of the arms, ankles or legs.
Your doctor may need to monitor your liver function, as Adalat can increase your liver enzymes. You may not experience any specific symptoms.
If any of the following happen, stop taking Adalat and tell your doctor immediately or go to Accident and Emergency at your nearest hospital:
- Chest pain;
- Rash, itching or hives on the skin;
- Swelling of the face, lips, tongue, or other parts of the body;
- Shortness of breath, wheezing, or trouble breathing;
- Signs of liver problems such as yellowing of the skin and/or eyes (jaundice);
- Signs of frequent infections such as fever, severe chills, sore throat or mouth ulcers.
These serious side effects are not common. If you have these side effects you may need urgent medical attention.
There have been reports of purple/brown discolouration of the skin or redness, flaking, and itching of the skin. Also, it has been reported for some people to develop a rash or blistering of the skin when they are exposed to sunlight. Tell your doctor if you experience any of these symptoms.
In a small number of cases of in vitro fertilisation, medicines like nifedipine appeared to have interfered with the normal function of sperm. This effect went away after the medicine was stopped. In those men who are taking Adalat tablets and are repeatedly unsuccessful in fathering a child by in vitro fertilisation, the medicine should be considered as one of the possible causes if no other explanation can be found.
Tell your doctor or pharmacist if you notice anything that is making you feel unwell. Other side effects not listed above may also occur in some people.
For further information talk to your doctor.