Adalat Oros

Generic Name: Nifedipine
Product Name: Adalat Oros

Indication

Adalat Oros contains the active ingredient nifedipine which belongs to a group of medicines called calcium channel blockers. Adalat Oros is mainly used for the treatment of high blood pressure (also called hypertension). This is often an asymptomatic condition where the pressure within the walls of blood vessels is too high. If left untreated hypertension can cause lead to serious effects such as stroke or heart attack. Adalat Oros when taken regularly helps to lower blood pressure. The other primary use of Adalat Oros is for prevention of angina attacks. This condition causes chest pain or discomfort when the heart muscle is deprived of oxygen. Adalat Oros helps reduce the frequency of angina attacks and improves exercise tolerance by dilating blood vessels that supply to the heart. However, it is not suitable for treatment of acute attacks (due to its slow onset of action) where medicines such as sublingual nitrates are required.

Action

Adalat Oros contains the active substance nifedipine. This medication belongs to a group of medicines called calcium channel blockers which inhibit the movement of calcium into cells within the heart and vessels. Calcium is an important component for contraction of muscle cells within the body. Adalat Oros acts specifically on cells within blood vessels to stop them from contracting, in order to dialte blood vessels. This lowers the tension in there walls causing a lowering in blood pressure. This is the main mechanism that Adalat Oros treats hypertension. In addition, Adalat Oros dilates blood vessels supplying the heart so the heart muscle gets more oxygen. Dilation of all peripheral vessels also reduces the load on the heart to pump against the resistant vessels. (Think of how much harder you would have to pump to get air into a tight hose compared to a wider one!) This is how it is thought to relieve angina. Remember that this is a disease caused by insufficient oxygen reaching the heart muscle to meet its demands.

Dose advice

Adalat Oros comes as round tablets that are rose-pink in colour. They are coated with a special substances to produce a delayed release in the body. The outer capsule of the tablets are not meant to be absorbed by the body so you may notice empty ‘ghost-tablets’ in your stools. All Adalat Oros tablets should be swallowed whole with water. You should not crush, cut or divide the tablets. Adalat can be taken with or without food. There are currently three dose of Adalat Oros available which contain 20, 30 or 60 milligrams of the active component nifedipine. They all come blister packs of 30 tablets. Before taking Adalat Oros it is important that you:

• Tell your doctor if you have any allergies to medicines, food dyes or preservatiives. Adalat Oros is not suitable if you are allergic to dihydrpyridine medications or any of the other inactive components of the tablets.
• Let your doctor know all the medications you are taking (including ones bought at the supermarket or chemist). This is important as Adalat Oros can react with other drugs in the body that use the same mechanisms for breaking down and excreting the drug.
• Inform your doctor of any medical conditions you may have or that you have experienced in the past including heart failure, low blood pressure, liver disease, diabetes, blockages within your gut or prolonged diarrhoea.
• Tell your doctor if you are pregnant or intend on becoming pregnant. Aldalat Oros should not be used during pregnancy or lactation. It can reduce oxygen supplies to the fetus and lead to fetal complications.
• In addition, Adalat Oros should not be used within 8 days of you suffering a heart attack.

Adalat Oros should always be taken as prescribed by your doctor. They will decide what dose is suitable for your specific condition and will monitor your response to the drug. They will also determine how long you should be treated with this medication. You should not cease the medication unless specifically told by your doctor or if you experience severe side effects. If you forget to take your usual dose of Adalat Oros at the correct time, you can still take it within 12 hours, then continue with the normal dose the next day. If you do not realise until after 12 hours you should skip that day’s dose but be sure to take the next day’s dose when it is due. Typical starting doses for Adalat Oros for treatment of high blood pressure is 20-30mg given once daily (usually in the morning). Your doctor will then slowly adjust the dose over 1-2 week, sometimes to up to 120mg, depending on your response. For treatment of angina doses of 30-90mg daily are used. If you have severe liver disease you may require lower doses than usual. In addition, if you are from a South Asian country you may also need to start on lower doses as some studies have shown that people from some ethnic backgrounds have trouble eliminating the drug from the body. Therefore if too high doses are used the drug could accumulate and cause side effects.

Schedule

Schedule 4

Common side effects

Like all medication Adalat Oros can cause some side effects as it is altering the normal chemicals within the body. The majority or side effects are mild and transient and will disappear with time or after the treatment is ceased. The most common side effects of Adalat Oros are listed below. These affect between 1-10% of patients taking the drug.

• Headaches.
• Flushing of the skin due to dilation of vessels.
• Asthenia which is a general feeling of weakness.
• Peripheral oedema- Which is accumulation of fluid within tissues causing swelling of the ankles or legs. This is generally worse for higher doses.
• Palpitations- Awareness of the heart beating or an irregular heart rhythm. .
• Constipation.
• Dizziness.
• Tiredness.
• Nausea.

Bleeding, tender or swollen gums, muscle pain, trembling, visual disturbances and an increase in the need to pass water may also occur, particularly in the early days of treatment. These side effects occur in approximately one patient in every 100-1000 who are taking the drug.

Uncommon side effects

There are some side effects of Adalat Oros that can be quite serious. These however are rare and occur in less than 1 out of 1000 patients. However, if you experience symptoms suggestive of any of the following side effects you should seek urgent medical advice.

• Allergic reactions- This may present as rash, itching or hives on the skin, swelling of the face, lips or tongue, or difficult or noisy breathing.
• Liver problems- Yellowing of the skin or eyes (jaundice) may be a sign of liver damage.
• Cardiovascular disorders- If you develop a fast or irregular heartbeat, episodes of fainting or chest pain whilst on this medication, it may be dropping your blood pressure too low and upsetting the supply of oxygen to the heart and brain.
• Bowel blockage- In rare cases the ‘ghost tablets’ may not be excreted and collect in the stomach causing a bowel obstruction. You may notice abdominal distension, vomiting or reduced passage of stools.

Note that the above lists of side effects are not exhaustive and new side effects can be discovered as more people use the drug. Therefore if you develop any worrying symptoms that you think may be related to this medication do not hesitate to discuss these with your doctor.

References

1. Adalat(TM) OROS- Consumer Medicine Information. Bayer Australia Ltd 2004. Available from: [URL Link]
2. Australian Medicines Handbook- 6.4.6 Nifedipine, AMH Pty Ltd. 2006.
3. MIMS online- Prescribing Information. Adalat Oros, MIMS Australia Pty Ltd 2003.

For further information talk to your doctor.