What is Ismo?
Ismo is a trade name for isosorbide mononitrate, a vasodilator used to treat angina pectoris due to coronary artery disease as a prophylactic treatment. It is not sufficiently fast acting to stop an acute episode of angina. It has also been used as a cervical dilator to speed delivery in obstetric hospitals
How does Ismo work?
Like all nitrates, Ismo works by dilating blood vessels to reduce the workload on the heart.
What does Ismo look like?
Ismo is supplied as a round orange pill with a strength of 20 mg and imprinted with “Ismo 20 W”.
Ismo dosing and administration
The standard dosage of Ismo is 20 mg three times a day.
Common adverse effects from Ismo
The most common side effect, occurring in more than thirty percent of patients is headache. This tends to occur only in the early stages of treatment. Other common side effects are fatigue, sleep disturbance, gastrointestinal upset, hypotension, loss of appetite and nausea. Hypotension with dizziness and nausea have been reported but generally disappear as treatment continues. Infrequently reported side effects have included tachycardia, vomiting, diarrhea, vertigo and dyspepsia. This last group of side effects have been linked to extended release forms of the drug. Other side effects which have been reported included dysuria, erectile dysfunction, neck stiffness, arthralgia, respiratory problems including bronchitis and pneumonia.
More information about isosorbide mononitrate side effects at this site: https://www.universaldrugstore.com/medications/Ismo/side-effects
Ismo warnings and precautions
Ismo treatment may occasionally need to be discontinued because of serious side effects including dizziness, headaches and nausea. Severe postural hypotension may occur even when only low doses of Ismo are being used. This may be accompanied by bradycardia and an exacerbation of angina pectoris. Angina resulting from hypertrophic cardiomyopathy may be exacerbated by nitrate therapy. Industrial workers who have had extensive exposure to organic nitrates have shown tolerance to nitrates and the unaccustomed withdrawal of nitrates from these workers have resulted in chest pain, severe heart attacks and death. This indicates a physical dependence associated with nitrates, but this has not yet been directly linked to normal clinical treatment with Ismo. Ismo has been linked to stillbirths and neonatal death in rats exposed to high doses of Ismo. Although there have been no clinical studies on human subjects, Ismo should only be used in pregnancy if there is a compelling potential benefit to the mother. Whether or not Ismo is present in human milk has not been definitely established, but caution should be used in prescribing this drug to nursing mothers. There has been no difference in response noted in elderly patients, but caution should be shown in prescribing to this age group and it is recommended that the starting dosage should be at the lower end of the scale. The safety of Ismo for pediatric use has not been established.
Interactions with Ismo
Drugs with which ismo has serious interactions may include sildenafil (Viagra) which may potentiate the vasodilatory action of Ismo and lead to serious side effects including syncope and heart attack. Calcium channel blockers and organic nitrates may cause severe hypotension in combination with Ismo.