Isosorbide Mononitrate: Price, Dosage & Where to Buy

Isosorbide mononitrate is an organic nitrate medicine used mainly to prevent and treat angina pectoris caused by coronary artery disease. It widens blood vessels, helping reduce the heart’s workload and its need for oxygen. The medicine requires a prescription in the United Kingdom, and it is available as a generic product under its medicine name.

Isosorbide mononitrate is indicated for the prevention and treatment of angina pectoris due to coronary artery disease. Angina is chest pain or discomfort related to the heart muscle not receiving enough oxygen-rich blood. This medicine is intended to reduce the likelihood of angina episodes and support treatment of the condition.

The oral medicine does not work sufficiently quickly to abort an acute anginal episode. New, severe, worsening, or persistent chest pain requires urgent medical assessment rather than reliance on this medicine alone.

Isosorbide mononitrate belongs to the organic nitrate class. After it is processed in the body, it releases signals that relax the smooth muscle in blood vessel walls. This causes blood vessels to widen, particularly veins, reducing the amount of blood returning to the heart.

The heart consequently has less work to do and requires less oxygen. Widening certain arteries may also improve blood flow through the coronary circulation.

The medicine’s blood-vessel-relaxing effect can lower blood pressure and may cause headache, dizziness, or light-headedness. Regular nitrate-free intervals are used because continuous exposure can lead to tolerance, meaning the effect may become less pronounced.

The label lists 10 mg and 20 mg film-coated tablets. The label lists 20 mg twice daily, with the doses seven hours apart, as the recommended regimen. The usual starting dose is 5 mg, described as half of a 10 mg tablet, for people of particularly small stature.

The label lists an increase to at least 10 mg by the second or third day of therapy in that situation. The label lists that dosage adjustments are not necessary for elderly patients or patients with altered hepatic or renal function. The label lists that doses above 20 mg twice daily, with the doses seven hours apart, have not been adequately studied.

The label lists that 5 mg twice daily is clearly effective only for the first day of a twice-daily regimen with the doses seven hours apart. The asymmetric regimen provides a daily nitrate-free interval intended to minimise tolerance.

A missed dose can reduce protection against angina. General pharmacy advice is to follow the prescribed schedule and seek advice from a pharmacist or doctor if the next dose is near.

A double dose should not be used to make up for a missed dose, because excessive vasodilation may cause hypotension, dizziness, fainting, or other harmful effects. Regular timing is particularly relevant because the label regimen includes a nitrate-free interval.

Animal reproduction studies in rats and rabbits found no evidence of harm to the fetus at the doses studied. However, there are no adequate and well-controlled studies in pregnant women, and animal findings may not predict human response.

The label states that isosorbide mononitrate should be used during pregnancy only if clearly needed. The label does not provide specific lactation advice, so pregnancy or breastfeeding should be discussed with a doctor or pharmacist.

Store at 20°C to 25°C and keep the tablets tightly closed to maintain quality. Protect the medicine from unsuitable storage conditions and keep it out of the reach of children. Follow the product label or pharmacist’s advice if storage conditions are unclear.