ISMO Side Effects

Generic Name: isosorbide mononitrate

Please note - some side effects for ISMO may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).

Side Effects of ISMO - for the Consumer

ISMO

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using ISMO:

Dizziness; headache; nausea.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); changes in vision; fainting; numbness of an arm or leg; severe stomach pain; sharp or crushing chest pain; sudden leg pain; sudden, severe headache; sudden shortness of breath; vomiting.

ISMO Side Effects - for the Professional

Ismo

The table below shows the frequencies of the adverse reactions observed in more than 1% of the subjects (a) in 6 placebo-controlled domestic studies in which patients in the active-treatment arm received 20 mg of isosorbide mononitrate twice daily, and (b) in all studies in which patients received isosorbide mononitrate in a variety of regimens. In parentheses, the same table shows the frequencies with which these adverse reactions led to discontinuation of treatment. Overall, 11% of the patients who received isosorbide mononitrate in the six controlled U.S. studies discontinued treatment because of adverse reactions. Most of these discontinued because of headache. “Dizziness” and nausea were also frequently associated with withdrawal from these studies.

Other adverse reactions, each reported by fewer than 1% of exposed patients, and in many cases of uncertain relation to drug treatment, were::

Cardiovascular: angina pectoris, arrhythmias, atrial fibrillation, hypotension, palpitations, postural hypotension, premature ventricular contractions, supraventricular tachycardia, syncope.

Dermatologic: pruritus, rash.

Gastrointestinal: abdominal pain, diarrhea, dyspepsia, tenesmus, tooth disorder, vomiting.

Genitourinary: dysuria, impotence, urinary frequency.

Miscellaneous: asthenia, blurred vision, cold sweat, diplopia, edema, malaise, neck stiffness, rigors.

Musculoskeletal: arthralgia.

Neurological: agitation, anxiey, confusion, dyscoordination, hypoesthesia, hypokinesia, increased appetite, insomnia, nervousness, nightmares.

Respiratory: bronchitis, pneumonia, upper-respiratory tract infection.

Extremely rarely, ordinary doses of organic nitrates have caused methemoglobinemia in normal-seeming patients; for futher discussion of its diagnosis and treatment see under OVERDOSAGE.

Side Effects by Body System

General

Isosorbide mononitrate is generally well-tolerated.

Nervous system

Nitrate-induced headaches are probably due to vasodilation, and may resolve spontaneously over days to weeks or respond to acetaminophen analgesia.

Nervous system side effects such as headache have occurred in up to 36% of patients. In a large multicenter trial, 1.2% of patients discontinued therapy due to headache. Up to 8% of patients experienced dizziness/vertigo symptoms.

Cardiovascular

Organic nitrates may induce a sudden drop in systemic blood pressure and enhanced vagal tone, resulting in possible inhibition of reflex tachycardia and syncope.

Cardiovascular side effects include flushing, increased heart rate, hypotension, and orthostasis. These are more likely in patients with hypovolemia or who are on antihypertensive medications. Syncope has been reported in rare cases. Due to tolerance to the antianginal effects of the drug, eccentric dosing is usually recommended. This typically means giving the drug upon wakening and again approximately seven hours later, leaving a "nitrate-free" period during the night to decrease the incidence of tolerance.

Gastrointestinal

Gastrointestinal side effects are relatively uncommon, and include nausea and constipation in 1% to 3% of patients.

Hypersensitivity

Hypersensitivity reactions, presenting as pruritus and drug rash, are reported with the organic nitrates.

Hematologic

Nitrates converted to nitrites may accelerate the oxidation of hemoglobin, resulting in abnormally high plasma concentrations of methemoglobin. While most cases of methemoglobinemia are asymptomatic, methemoglobin levels greater than 60% usually induce symptoms, particularly in the presence of underlying coronary artery disease. Treatment in symptomatic persons is methylene blue 1% solution 2 mg/kg intravenously over 10 minutes. It is recommended that affected patients be screened for NADP-methemoglobin reductase deficiency.

A rare hematologic side effect of nitrates is methemoglobinemia.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date, and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This information does not endorse drugs, diagnose patients, or recommend therapy. This drug information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug of drug combination is safe, effective, or appropriate for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of information provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse, or pharmacist.