Prescription Drug Information: Isosorbide Dinitrate (Page 2 of 2)

OVERDOSAGE

Hemodynamic Effects

The ill effects of isosorbide dinitrate overdose are generally the results of isosorbide dinitrate’s capacity to induce vasodilatation, venous pooling, reduced cardiac output, and hypotension. These hemodynamic changes may have protean manifestations, including increased intracranial pressure, with any or all of persistent throbbing headache, confusion, and moderate fever; vertigo; palpitations; visual disturbances; nausea and vomiting (possibly with colic and even bloody diarrhea); syncope (especially in the upright posture); air hunger and dyspnea, later followed by reduced ventilatory effort; diaphoresis, with the skin either flushed or cold and clammy; heart block and bradycardia, paralysis; coma; seizures; and death.

Laboratory determinations of serum levels of isosorbide dinitrate and its metabolites are not widely available, and such determinations have, in any event, no established role in the management of isosorbide dinitrate overdose.

There are no data suggesting what dose of isosorbide dinitrate is likely to be life-threatening in humans. In rats, the median acute lethal dose (LD 50 ) was found to be 1100 mg/kg.

No data are available to suggest physiological maneuvers ( e.g. , maneuvers to change the pH of the urine) that might accelerate elimination of isosorbide dinitrate and its active metabolites. Similarly, it is not known which, if any, of these substances can usefully be removed from the body by hemodialysis.

No specific antagonist to the vasodilator effects of isosorbide dinitrate is known, and no intervention has been subject to controlled studies as a therapy for isosorbide dinitrate overdose. Because the hypotension associated with isosorbide dinitrate overdose is the result of venodilatation and arterial hypovolemia, prudent therapy in this situation should be directed toward increase in central fluid volume. Passive elevation of the patient’s legs may be sufficient, but intravenous infusion of normal saline or similar fluid may also be necessary.

The use of epinephrine or other arterial vasoconstrictors in this setting is likely to do more harm than good.

In patients with renal disease or congestive heart failure, therapy resulting in central volume expansion is not without hazard. Treatment of isosorbide dinitrate overdosage in these patients may be subtle and difficult, and invasive monitoring may be required.

Methemoglobinemia

Nitrate ions liberated during metabolism of isosorbide dinitrate can oxidize hemoglobin into methemoglobin. Even in patients totally without cytochrome b 5 reductase activity, however, and even assuming that the nitrate moieties of isosorbide dinitrate are quantitatively applied to oxidation of hemoglobin, about 1 mg/kg of isosorbide dinitrate should be required before any of these patients manifests clinically significant (≥10%) methemoglobinemia. In patients with normal reductase function, significant production of methemoglobin should require even larger doses of isosorbide dinitrate. In one study in which 36 patients received 2 to 4 weeks of continuous nitroglycerin therapy at 3.1 to 4.4 mg/hr (equivalent, in total administered dose of nitrate ions, to 4.8 to 6.9 mg of bioavailable isosorbide dinitrate per hour), the average methemoglobin level measured was 0.2%; this was comparable to that observed in parallel patients who received placebo.

Notwithstanding these observations, there are case reports of significant methemoglobinemia in association with moderate overdoses of organic nitrates. None of the affected patients had been thought to be unusually susceptible.

Methemoglobin levels are available from most clinical laboratories. The diagnosis should be suspected in patients who exhibit signs of impaired oxygen delivery despite adequate cardiac output and adequate arterial pO 2 . Classically, methemoglobinemic blood is described as chocolate brown, without color change on exposure to air.

When methemoglobinemia is diagnosed, the treatment of choice is methylene blue, 1 to 2 mg/kg intravenously.

DOSAGE AND ADMINISTRATION

As noted under ” CLINICAL PHARMACOLOGY ,” multiple-dose studies with isosorbide dinitrate and other nitrates have shown that maintenance of continuous 24-hour plasma levels results in refractory tolerance. Every dosing regimen for isosorbide dinitrate tablets must provide a daily dose-free interval to minimize the development of this tolerance. With immediate-release isosorbide dinitrate, it appears that one daily dose-free interval must be at least 14 hours long.

As also noted under ” CLINICAL PHARMACOLOGY ,” the effects of the second and later doses have been smaller and shorter-lasting than the effects of the first.

Large controlled studies with other nitrates suggest that no dosing regimen with isosorbide dinitrate tablets should be expected to provide more than about 12 hours of continuous anti-anginal efficacy per day.

As with all titratable drugs, it is important to administer the minimum dose which produces the desired clinical effect. The usual starting dose of isosorbide dinitrate is 5 mg to 20 mg, two or three times daily. For maintenance therapy, 10 mg to 40 mg, two or three times daily is recommended. Some patients may require higher doses. A daily dose-free interval of at least 14 hours is advisable to minimize tolerance. The optimal interval will vary with the individual patient, dose and regimen.

HOW SUPPLIED

Product: 63739-367

NDC: 63739-367-10 10 TABLET in a BLISTER PACK / 10 in a BOX, UNIT-DOSE

Product: 63739-569

NDC: 63739-569-10 10 TABLET in a BLISTER PACK / 10 in a BOX, UNIT-DOSE

CLINICAL STUDIES

In clinical trials, immediate-release oral isosorbide dinitrate has been administered in a variety of regimens, with total daily doses ranging from 30 mg to 480 mg. Controlled trials of single oral doses of isosorbide dinitrate have demonstrated effective reductions in exercise-related angina for up to 8 hours. Anti-anginal activity is present about 1 hour after dosing.

Most controlled trials of multiple-dose oral isosorbide dinitrate taken every 12 hours (or more frequently) for several weeks have shown statistically significant anti-anginal efficacy for only 2 hours after dosing. Once-daily regimens, and regimens with one daily dose-free interval of at least 14 hours ( e.g. , a regimen providing doses at 0800, 1400 and 1800 hours), have shown efficacy after the first dose of each day that was similar to that shown in the single-dose studies cited above. The effects of the second and later doses have been smaller and shorter-lasting than the effect of the first.

From large, well-controlled studies of other nitrates, it is reasonable to believe that the maximal achievable daily duration of anti-anginal effect from isosorbide dinitrate is about 12 hours. No dosing regimen for isosorbide dinitrate, however, has ever actually been shown to achieve this duration of effect. One study of 8 patients, who were administered a pretitrated dose (average 27.5 mg) of immediate-release isosorbide dinitrate at 0800, 1300, and 1800 hours for 2 weeks, revealed that significant anti-anginal effectiveness was discontinuous and totaled about 6 hours in a 24 hour period.

Manufactured by:

PAR PHARMACEUTICAL

Chestnut Ridge, NY 10977

Revised 02/2016

Isosorbide Dinitrate Tablets, USP

Label Image
(click image for full-size original)

Isosorbide Dinitrate Tablets, USP

Label Image
(click image for full-size original)
ISOSORBIDE DINITRATE
isosorbide dinitrate tablet
Product Information
Product Type HUMAN PRESCRIPTION DRUG Item Code (Source) NDC:63739-367(NDC:49884-022)
Route of Administration ORAL DEA Schedule
Active Ingredient/Active Moiety
Ingredient Name Basis of Strength Strength
ISOSORBIDE DINITRATE (ISOSORBIDE DINITRATE) ISOSORBIDE DINITRATE 20 mg
Inactive Ingredients
Ingredient Name Strength
FD&C BLUE NO. 1
D&C YELLOW NO. 10
FD&C YELLOW NO. 6
ANHYDROUS LACTOSE
MICROCRYSTALLINE CELLULOSE
SODIUM STARCH GLYCOLATE TYPE A CORN
ISOPROPYL ALCOHOL
Product Characteristics
Color green Score 2 pieces
Shape ROUND Size 8mm
Flavor Imprint Code Par;022
Contains
Packaging
# Item Code Package Description Multilevel Packaging
1 NDC:63739-367-10 10 BLISTER PACK in 1 BOX, UNIT-DOSE contains a BLISTER PACK
1 10 TABLET in 1 BLISTER PACK This package is contained within the BOX, UNIT-DOSE (63739-367-10)
Marketing Information
Marketing Category Application Number or Monograph Citation Marketing Start Date Marketing End Date
ANDA ANDA087537 12/15/1981
ISOSORBIDE DINITRATE
isosorbide dinitrate tablet
Product Information
Product Type HUMAN PRESCRIPTION DRUG Item Code (Source) NDC:63739-569(NDC:49884-021)
Route of Administration ORAL DEA Schedule
Active Ingredient/Active Moiety
Ingredient Name Basis of Strength Strength
ISOSORBIDE DINITRATE (ISOSORBIDE DINITRATE) ISOSORBIDE DINITRATE 10 mg
Inactive Ingredients
Ingredient Name Strength
ANHYDROUS LACTOSE
MICROCRYSTALLINE CELLULOSE
SODIUM STARCH GLYCOLATE TYPE A CORN
STEARIC ACID
MAGNESIUM STEARATE
Product Characteristics
Color white Score 2 pieces
Shape ROUND Size 8mm
Flavor Imprint Code Par;021
Contains
Packaging
# Item Code Package Description Multilevel Packaging
1 NDC:63739-569-10 10 BLISTER PACK in 1 BOX, UNIT-DOSE contains a BLISTER PACK
1 10 TABLET in 1 BLISTER PACK This package is contained within the BOX, UNIT-DOSE (63739-569-10)
Marketing Information
Marketing Category Application Number or Monograph Citation Marketing Start Date Marketing End Date
ANDA ANDA086925 12/22/1979
Labeler — McKesson Corporation dba SKY Packaging (140529962)
Establishment
Name Address ID/FEI Operations
Legacy Pharmaceutical Packaging, LLC 143213275 repack (63739-367), repack (63739-569), relabel (63739-367), relabel (63739-569)

Revised: 11/2020 McKesson Corporation dba SKY Packaging

Page 2 of 2 1 2

RxDrugLabels.com provides trustworthy package insert and label information about marketed prescription drugs as submitted by manufacturers to the U.S. Food and Drug Administration. Package information is not reviewed or updated separately by RxDrugLabels.com. Every individual prescription drug label and package insert entry contains a unique identifier which can be used to secure further details directly from the U.S. National Institutes of Health and/or the FDA.

Medication Sections

Medication Information by RSS

As a leading independent provider of trustworthy medication information, we source our database directly from the FDA's central repository of drug labels and package inserts under the Structured Product Labeling standard. RxDrugLabels.com provides the full prescription-only subset of the FDA's repository. Medication information provided here is not intended as a substitute for direct consultation with a qualified health professional.

Terms of Use | Copyright © 2020. All Rights Reserved.