Loading doses of inamrinone injection should be administered as
supplied (undiluted). Infusions of inamrinone may be administered in normal or
half normal saline solution to a concentration of 1 mg/mL to 3 mg/mL. Diluted
solutions should be used within 24 hours.
Inamrinone injection may be administered into running dextrose (glucose)
infusions through a Y-Connector or directly into the tubing where preferable.
A chemical interaction occurs slowly over a 24-hour period when
the intravenous solution of inamrinone is mixed directly
with dextrose (glucose)-containing solutions. THEREFORE,
INAMRINONE SHOULD NOT BE DILUTED WITH SOLUTIONS THAT CONTAIN DEXTROSE (GLUCOSE)
PRIOR TO INJECTION.
A chemical interaction occurs immediately, which is evidenced by the
formation of a precipitate when furosemide is injected into an intravenous line
of an infusion of inamrinone. Therefore, furosemide should not be administered
in intravenous lines containing inamrinone.
The following procedure is recommended for the administration of inamrinone
1. Initiate therapy with a 0.75 mg/kg loading dose given slowly over 2 to 3
LOADING DOSE DETERMINATION
0.75 mg/kg (undiluted)
Patient Weight in kg
mL of undiluted Inamrinone Injection
2. Continue therapy with a maintenance infusion between 5 mcg/kg/min and 10
3. Based on clinical response, an additional loading dose of 0.75 mg/kg may
be given 30 minutes after the initiation of therapy.
4. The rate of infusion usually ranges from 5 mcg/kg/min to 10 mcg/kg/min
such that the recommended total daily dose (including loading doses) does not
exceed 10 mg/kg. A limited number of patients studied at higher doses support a
dosage regimen up to 18 mg/kg/day for shortened durations of therapy.
The following infusion rate chart may be used to assure that the calculations
are made correctly.
To utilize the chart, the concentration of inamrinone
infusion solution used must be 2.5 mg/mL (2500 mcg/mL). This
concentration is prepared by mixing the inamrinone solution with an equal volume
of diluent (normal or half normal saline).
*Dilution: To prepare the 2.5 mg/mL
concentration recommended for infusion mix inamrinone with an equal
volume of diluent. For example, mix three 20 mL vials of inamrinone
(3 x 20 mL = 60 mL) with 60 mL of diluent for a total volume of 120
mL of the final 2.5 mg/mL solution of inamrinone.
INAMRINONE IV INFUSION RATE (mL/hr) CHART
Using 2.5 mg/mL Infusion Concentration*
Patient Weight in kg
Example: A 70 kg patient would require a loading dose of 10.5 mL of undiluted
inamrinone. If the physician selects a dose of 7.5 mcg/kg/min for the infusion,
the flow rate would be 13 mL/hr at the 2.5 mg/mL concentration of inamrinone.
5. The rate of administration and the duration of therapy should be adjusted
according to the response of the patient. The physician may wish to reduce or
titrate the infusion downward based on clinical responsiveness or untoward
The above dosing regimens can be expected to place most patients’ plasma
concentration of inamrinone at approximately 3 mcg/mL. Increases in cardiac
index show a linear relationship to plasma concentration of a range of 0.5
mcg/mL to 7 mcg/mL. No observations have been made at greater plasma
Patient improvement may be reflected by increases in cardiac output,
reduction in pulmonary capillary wedge pressure, and such clinical responses as
a lessening of dyspnea and an improvement in other symptoms of heart failure,
such as orthopnea and fatigue.
Monitoring central venous pressure (CVP) may be valuable in the assessment of
hypotension and fluid balance management. Prior correction or adjustment of
fluid/electrolytes is essential to obtain satisfactory response with inamrinone.
Parenteral drug products should be inspected visually and should not be used
if particulate matter or discoloration is observed.
[CRCL >10 ml/min]: No change
[< 10 ml/min]: Administer 50% to 75% of dose.
Specific guidelines not available. Refer to [<10 ml/min] dosing.
National Institutes of Health, U.S. National Library of Medicine,
DailyMed Database. Provides access to the latest drug monographs submitted to the
Food and Drug Administration (FDA). Please review the latest applicable package insert for
additional information and possible updates. A local search
option of this data can be found here.
The authors make no claims of the accuracy of the information contained herein; and these suggested doses are not a substitute for clinical
judgment. Neither GlobalRPh Inc. nor any other party involved in the
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