Isoptin SR 240mg (Verapamil)

Isoptin general information

What is Isoptin used for?

Isoptin tablets SR 240mg are used to treat essential hypertension, which is high blood pressure when at rest. Although there are usually no other symptoms, high blood pressure increases risk of cardiovascular disease and Isoptin tablets SR 240mg reduce the risk of stroke and heart attack, by lowering blood pressure to normal resting levels. Isoptin tablets SR 240mg are also used to treat chronic stable angina, to prevent symptoms like chest pain and to prevent heart attack; also to treat angina due to coronary artery spasm, which is an acute angina attack which can occur at rest. For patients who have recently had a heart attack (myocardial infarction) Isoptin SR 240mg is used for secondary prevention of another acute heart attack in cases where other medications like beta blockers cannot be tolerated.

How does Isoptin work?

Isoptin tablets SR 240mg contain verapamil, which is a calcium channel blocker that inhibits the inflow of calcium ions across specific calcium channels in the cell membrane into smooth muscle cells of the heart (myocardium) and blood vessel walls (only arteries). Calcium is needed for smooth muscle cells to contract, so by blocking calcium channels, smooth muscle cells contraction is prevented. Verapamil in Isoptin tablets SR 240mg blocks calcium channels in smooth muscle cells, allowing peripheral arteries to relax and widen (vasodilation) and this reduces the workload on the heart, the force needed for the heart to pump blood around the body (negative inotropic effect), increases oxygen supply to the heart, and decreases blood pressure. Isoptin tablets SR 240mg also causes widening of the main arteries of the heart, increasing the oxygen supply to the heart and, as the heart workload is reduced, the demand for oxygen is also reduced, which prevents chest pain symptoms of angina caused by lack of oxygen to the heart muscle.

What does Isoptin contain?

Isoptin tablets SR 240mg contain the active ingredient verapamil hydrochloride, a calcium channel blocker used to treat hypertension, angina and arrhythmia. They also contain calcium hydrogen phosphate, cellulose-microcrystalline, croscarmellose sodium, magnesium stearate, silica-colloidal anhydrous, hypromellose, talc-purified, sodium lauryl sulfate, Macrogol 6000 and titanium dioxide.

Treating Angina with Isoptin

Isoptin tablets SR 240mg contains verapamil, a calcium channel blocker that is used to treat angina, to prevent symptoms like chest pain and to prevent heart attack. Verapamil in Isoptin tablets SR 240mg blocks the inflow of calcium ions, which are needed for contraction, into smooth muscle cells of the heart and blood vessel walls (only arteries). This causes blood vessel walls to relax and peripheral arteries to widen. The action of verapamil in Isoptin SR 240mg reduces the workload on the heart and its demand for oxygen, while at the same time increasing oxygen supply to the heart, which prevents chest pain symptoms of angina caused by lack of oxygen to the heart muscle.

Isoptin for hypertension (high blood pressure)

Isoptin tablets SR 240mg contains verapamil, a calcium channel blocker that is used to treat acute hypertension (high blood pressure at rest), to lower blood pressure in people who are at risk of cardiovascular disease due to high blood pressure. Verapamil in Isoptin SR 240mg inhibits the inflow of calcium ions across specific calcium channels in the cell membrane into smooth muscle cells of the heart (myocardium) and blood vessel walls (only arteries). Calcium is needed for smooth muscle cells to contract, so by blocking calcium channels, smooth muscle cells contraction is prevented. The result is that the smooth muscle cells relax, which causes peripheral arteries to widen (vasodilation). This reduces peripheral vascular resistance, which reduces workload on the heart, (force needed for the heart to pump blood around the body), increases oxygen supply to the heart, and decreases blood pressure.

What are the side effects of Isoptin?

The most commonly reported side effects when taking Isoptin tablets SR 240mg include: headache oedema (swelling of the ankles, feet, face or hands), flushing, palpitations, tiredness, drowsiness, dizziness, abdominal and pain nausea.

When should Isoptin not be used?

You should not use Isoptin tablets SR 240mg if you:

• are allergic to verapamil or any ingredients in Isoptin
• are pregnant or are breastfeeding
• have kidney or liver disease
• have certain types of abnormal heart rhythm like sick sinus syndrome or atrial fibrillation
• have heart problems including, cardiogenic shock, congestive heart failure, left ventricular failure or myocardial infarction
• have impaired neuromuscular transmission, such as with myasthenia gravis, Lambert-Eaton syndrome, advanced Duchenne muscular dystrophy
• have hypotension (low blood pressure)
• have a certain type of tumour in the head
• are taking medicines that interact with Isoptin, including beta-blockers like propranolol, digoxin for heart failure, the antiarrhythmics quinidine, flecainide and disopyramide, statins for high cholesterol like simvastatin, the antiepileptic carbamazepine, inhalation anaesthetics like halothane, cimetidine and ranitidine for gastric ulcers or reflux, lithium, buspirone and midazolam for mood disorders, the antiepileptic phenytoin, antibiotics like erythromycin, clarithromycin and rifampicin, sulfinpyrazone and colchicine for gout, theophylline for asthma, the antivirals atazanavir and ritonavir, immunosuppressants like cyclosporine and tacrolimus, the anti-cancer drug doxorubicin, the antidiabetic drug glibenclamide, the anti-inflammatory aspirin, grapefruit juice and alcohol

What medications interact with Isoptin?

Several medications interact with Isoptin and should either not be taken while you are taking Isoptin or only after discussion and instruction from your doctor:

• Drugs that cause a serious reaction with Isoptin: beta-blockers like propranolol, the antiarrhythmics quinidine, flecainide, and disopyramide, inhalation anaesthetics like halothane, the anti-inflammatory aspirin
• Drugs that affect Isoptin: cimetidine and ranitidine for gastric ulcers or reflux, the antiepileptic phenytoin, antibiotics like erythromycin, clarithromycin and rifampicin, sulfinpyrazone for gout, the antivirals atazanavir and ritonavir, grapefruit juice and alcohol
• Drugs that are affected by Isoptin: digoxin for heart failure, statins for high cholesterol like simvastatin, the antiepileptic carbamazepine, lithium, buspirone and midazolam for mood disorders, theophylline for asthma, colchicine for gout, immunosuppressants like cyclosporine and tacrolimus, the anti-cancer drug doxorubicin, the antidiabetic drug glibenclamide

How should Isoptin be taken?

You should take your Isoptin tablets SR 240mg with a glass of water, swallowed whole, once or twice daily, with food. The dose you take and for how long will depend on your condition and should be as recommended by your doctor. If required your doctor may increase your dose. You should continue to take your Isoptin tablets SR 240mg for as long as recommended by your doctor.

How long should you take Isoptin?

You should continue to take your Isoptin tablets SR 240mg for as long as recommended by your doctor.

Missed dose of Isoptin

If you miss a dose of Isoptin tablets SR 240mg take it as soon as you remember, unless it is time to take the next dose, then skip the missed dose. Do not take a double dose.

How should Isoptin be stored?

You should store your Isoptin below 25°C in a cool dry place.