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(C) Vancouver
General Hospital.
This monograph may not be reproduced without permission.
For further information, please contact a Pharmacist. |
NAME OF DRUG
argatroban
CLASSIFICATION
Anticoagulant
INDICATIONS
- anticoagulant to be used in patients who develop heparin-induced
thrombocytopenia (HIT); for use as an alternative to danaparoid in patients
with renal dysfunction
RECONSTITUTION AND STABILITY
- store vials at room temperature - protect vials from light - stable in
infusion solutions for 24 hours at room temperature
COMPATIBILITY
- compatible with D5W, NS, Ringers Solution - incompatible with other drugs
ROUTES OF ADMINISTRATION
- IV infusion
- dilute to 1 mg/mL concentration as follows: add 250 mg (= 2.5 mL; 1
vial) to 250mL IV solution or 500mg (=5mL; 2 vials) to 500mL IV solution
VH & HSC ADMINISTRATION POLICY
RESTRICTED TO HEMATOLOGY
H - The IV infusion rate must be controlled by an automated infusion control
device.
DOSAGE
Initial Dose: 0.5-1 mcg/kg/minute as follows:
| Infusion Rates
Argatroban Concentration 1 mg/mL |
| Body Weight (kg) |
Infusion Rate for DOSE:
0.5 mcg/kg/minute |
Infusion Rate for DOSE:
1 mcg/kg/minute |
Infusion Rate for DOSE:
1.5 mcg/kg/minute |
Infusion Rate for DOSE:
2 mcg/kg/minute |
| 50 |
1.5 mL/hour |
3.0 mL/hour |
4.5 mL/hour |
6.0 mL/hour |
| 60 |
1.8 mL/hour |
3.6 mL/hour |
5.4 mL/hour |
7.2 mL/hour |
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70
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2.1 mL/hour |
4.2 mL/hour |
6.3 mL/hour |
8.4 mL/hour |
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80
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2.4 mL/hour |
4.8 mL/hour |
7.2 mL/hour |
9.6 mL/hour |
|
90
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2.7 mL/hour |
5.4 mL/hour |
8.1 mL/hour |
10.8 mL/hour |
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100
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3.0 mL/hour |
6.0 mL/hour |
9.0 mL/hour |
12.0 mL/hour |
|
110
|
3.3 mL/hour |
6.6 mL/hour |
9.9 mL/hour |
13.2 mL/hour |
|
120
|
3.6 mL/hour |
7.2 mL/hour |
10.8 mL/hour |
14.4 mL/hour |
- check aPTT 2 hours after initiating therapy and following any dosage
adjustment; maintain aPTT 1.5-3 times baseline (not to exceed 100 seconds)
- adjust dosage upward (to maximum 10 mcg/kg/minute) according
to aPTT by increments of 0.25-0.5 mcg/minute
- dosage adjustment not required in renal impairment, however initial dosage
should be reduced to 0.5mcg/kg/minute with hepatic impairment,
increasing by increments of 0.25 mcg/kg/minute
POTENTIAL HAZARDS OF PARENTERAL ADMINISTRATION
- overdosage - hemorrhage (treatment - stop infusion, check aPTT; no specific
antidote, fresh frozen plasma may be indicated)
- adverse effects (>2%) include major/minor bleeding,
fever, sepsis, pain, hypotension, ventricular tachycardia, cardiac arrest,
bradycardia, myocardial infarction, dyspnea, headache, cough
IMPORTANT IMPLICATIONS
- anticoagulant effects attain steady-state levels within 2.5 hours
following initiation of argatroban or dosage adjustment
- upon cessation of argatroban, little or no argatroban remains after 4
hours
- monitor aPTT 2 hours after initiation and after each dosage change then
daily once aPTT 1.5-3.0 times initial baseline value
- Co-administration of warfarin and argatroban:
- the INR will increase with argatroban; measure INR daily with
co-administration of argatroban and warfarin
- with argatroban doses up to 2 mcg/kg/minute, an INR of 4.0 in patients
receiving warfarin may be interpreted as an INR between 2-3 attributed
to warfarin alone. Argatroban infusion should be stopped when the INR is
> 4.0 and a repeat INR obtained after 4-6 hours. If the repeat INR is
subtherapeutic, argatroban infusion should be resumed and this procedure
repeated daily until INR is therapeutic
- with argatroban doses greater then 2 mcg/kg/minute, interpretation of
INR on combined therapy is less well established. It is recommended to
temporarily reduce the argatroban dose to 2 mcg/kg/minute and obtain an
INR 4-6 hours later.
- gastrointestinal side effects include nausea, vomiting and diarrhea
Rev. Nov 2006