Drug information of Dalteparin


Dalteparin

Drug group: Anticoagulants

Dalteparin, a low molecular weight heparin (LMWH) prepared by nitrous acid degradation of unfractionated heparin of porcine intestinal mucosa origin, is an anticoagulant.

It is composed of strongly acidic sulphated polysaccharide chains with an average molecular weight of 5000 and about 90% of the material within the range of 2000-9000. LMWHs have a more predictable response, a greater bioavailability, and a longer anti-Xa half life than unfractionated heparin.

Dalteparin can also be safely used in most pregnant women. Low molecular weight heparins are less effective at inactivating factor IIa due to their shorter length compared to unfractionated heparin.

Mechanism of effect

Dalteparin potentiates the activity of ATIII, inhibiting the formation of both factor Xa and thrombin. The main difference between dalteparin and unfractionated heparin (UH) is that dalteparin preferentially inactivates factor Xa. As a result, only a slight increase in clotting time [(i.e. activated partial thomboplastin time (APTT)] is observed relative to UH. For this same reason, APTT is not used to monitor the effects of dalteparin except as an indicator for overdosage.

Pharmacodynamic

Dalteparin has an antithrombin binding site that is essential for high affinity binding to the plasma protein antithrombin (ATIII). Anti-Xa activity of plasma is used as both as an estimate of clotting activity, and as a basis to determine dosage.

Its use should be avoided in patients with a creatinine clearance less than 20mL/min. In these patients, unfractionated heparin should only be used. As for monitoring, active partial thromboplastin time (aPTT) will only increase at high doses of low molecular weight heparins (LMWH). Therefore, monitoring aPTT is not recommended. However, anti-Xa activity can be measured to monitor the efficacy of the LMWH.

Pharmacokinetics

  • Half-Life: 3-5 hr
  • Onset of action: 1-2 hr (anti Xa activity)
  • Peak plasma time: 4 hr
  • Duration: >12hr
  • Peak plasma concentration: 0.19 IU/mL (2500 IU dose)
  • Protein binding: Low
  • Bioavailability: 81-93%
  • Vd: 40-60 mL/kg
  • Excretion: Urine
  • Clearance: 15-25 mL/hr/kg (dose-dependent)

Drug indications

cardiovascular conditions

Dosage

Adult

Deep Vein Thrombosis Prophylaxis

Hip Replacement

  • PostOp Start
  • 2500 units SC 4-8 hr postsurgery, THEREAFTER 5000 units qDay
  • PreOp Start
  • On day of surgery: 2500 IU SC within 2 hours presurgery, THEN 2500 units SC 4-8 hr postsurgery, THEREAFTER 5000 units SC qDay (administration: At least 6 hr between first post-op dose & Post-op Day 1 dose)
  • Evening before Surgery: 5000 units SC 10-14 hr presurgery, THEN 5000 units SC 4-8 hr postsurgery, THEREAFTER 5000 units SC qDay

Abdominal Surgery

  • 2500 IU SC 1-2 hr preop, THEREAFTER 2500 units SC qDay
  • High risk of thromboembolic complications (eg, malignancy): 5000 units SC evening before surgery, THEN 5000 units qDay (first dose may be evenly split in a preop & postop dose)

Unstable Angina & Non-Q-Wave MI

120 IU/kg SC q12hr for 5-8 days (concurrent with aspirin 75-165 mg qDay) 

Not to exceed 10,000 units/dose or 18,000 units/day

Treatment Duration: Continue until patient stabilized; 5-10 days usual

Extended VTE Treatment in Patients with Cancer

200 units IU/kg SC qDay for 30 days, THEN 

Months 2-6: 150 units/kg SC qDay

Not to exceed 18,000 units daily

Treatment Duration: 5-10 days usual

Severe Mobility Restriction: 5000 units SC qDay

Pediatric

Safety & efficacy not established

Drug contraindications

thrombocytopenia

Alerts

Epidural or spinal hematomas may occur in patients anticoagulated with LMWH or heparinoids who receive neuraxial (epidural/spinal) anesthesia or spinal puncture

These hematomas may result in long-term or permanent paralysis

Patients should be frequently monitored for signs and symptoms of neurologic impairment; if neurological compromise noted, urgent treatment necessary

Optimal timing between the administration of dalteparin and neuraxial procedures is not known

Physicians should consider the benefits versus risk before neuraxial intervention in patients anticoagulated or to be anticoagulated for thromboprophylaxis

Factors increasing risk of epidural or spinal hematomas

  • Indwelling epidural catheters
  • Concomitant use of other drugs that affect hemostasis (eg, NSAIDs, platelet inhibitors, other anticoagulants)
  • History of traumatic or repeated epidural or spinal punctures
  • History of spinal deformity or spinal surgery

Points of recommendation

Follow all directions on your prescription label. Do not use this medicine in larger or smaller amounts or for longer than recommended.

Do not mix dalteparin with other medications in the same syringe unless your doctor tells you to.

Prepare your dose in a syringe only when you are ready to give yourself an injection. Do not use dalteparin if it has changed colors or has particles in it. Call your pharmacist for new medication.

You should be sitting or lying down during the injection. Do not inject dalteparin into a muscle.

Use a different place on your stomach each time you give the injection. Your care provider will show you the best places on your body to inject the medication. Do not inject into the same place two times in a row.

Use a disposable needle only once. Keep this container out of the reach of children.

Tell any doctor who treats you that you are using dalteparin. If you need surgery or dental work, tell the surgeon or dentist ahead of time that you are using this medication. If you need anesthesia for a medical procedure or surgery, you may need to stop using dalteparin for a short time.

While using dalteparin, your blood and your stool (bowel movement) may need to be tested often. Your nerve and muscle function may also need to be tested.

Store dalteparin vials (bottles) at room temperature away from moisture and heat. Once you have used a vial for the first time, the medicine will keep at room temperature for up to 2 weeks. Throw away the vial after 2 weeks have passed since you first punctured the vial, even if there is still medicine left inside.

Use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

Pregnancy level

HAVE NOT BEEN ESTABLISHED


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