Innohep (tinzaparin sodium) injectable
The following drug information is obtained from various newswires, published
medical journal articles, and medical conference presentations.
Deep vein thrombosis with or without pulmonary embolism when administered in conjunction with warfarin sodium
General Information
Innohep (tinzaparin sodium) injectable formulation is indicated
for the treatment of acute symptomatic deep vein thrombosis, with
or without pulmonary embolism when administered in conjunction with
warfarin sodium. It is available in a multiple dose 2mL vial, by
prescription only.
Clinical Results
A randomized, multicenter, double-blind study of Innohep was
held involving 435 hospitalized subjects with symptomatic, proximal
DVT. Subjects ranged in age from 19 - 92 years, with the mean
falling around 61 years of age. 55% were male and 88% were white,
8% were black. Innohep SC was administered to some subjects once
daily according to body weight (175 IU/kg) along with a placebo IV
bolus followed by continuous placebo IV infusion. Others were given
unfractionated heparin as an initial IV bolus dose (5,000 IU)
followed by continuous IV infusion of unfractionated heparin with
the rate adjusted to the aPTT (1.5 to 2.5 times control value) and
a once daily SC placebo injection. Subjects underwent treatment for
6 days and both groups also received oral warfarin sodium starting
on Day 2 continuing to Day 90 with doses titrated to a target INR
of 2.0 to 3.0. The 90 day cumulative thromboembolic (TE) rate
(recurrent DVT or PT) was not significantly different than the rate
with unfractionated heparin.
Side Effects
Innohep is contraindicated in patients who have a history of
heparin-induced thrombocytopenia, patients with active bleeding and
patients with hypersensitivity to tinzaparin sodium. Patients with
a known sensitivity to heparin, sulfites, benzyl alcohol or pork
products should not use Innohep.
Innohep is not intended for IV or IM administration.
Common side effects include, but are not limited to:
- Bleeding
- Thrombocytopenia
- Mild local pain around injection site
There are many other precautions that should be considered
before taking Innohep.
Nursing mothers should know that trace amounts of the drug were
found in the milk of test animals. There have also been reports of
fetal mortality/miscarriage in women who had high risk pregnancies
and were taking Innohep. One incident each of Down's syndrome,
optic nerve hypoplasia and cleft palate were reported by pregnant
women taking Innohep. However, no conclusive studies have been done
concerning a cause and effect relationship in these cases.
Mechanism of Action
Tinzaparin sodium is a low molecular weight heparin with
antithombotic properties. Tinzaparin sodium inhibits reactions that
lead to the clotting of blood including the formation of fibrin
clots, both in vitro and in vivo. It acts as a
potent co-inhibitor of several activated coagulation factors,
especially factors Xa and Iia (thrombin). The primary inhibitory
activity is mediated through the plasma protease inhibitor,
antithrombin.
Bleeding time is usually unaffected by tinzaparin sodium.
Activated partial thromboplastin time (aPTT) is prolonged by
therapeutic doses of tinzaparin sodium used in the treatment of
deep vein thrombosis (DVT). Prothrombin time (PT) may be slightly
prolonged with tinzaparin sodium treatment but usually remains
within the normal range. Neither aPTT nor PT can be used for
therapeutic monitoring of tinzaparin sodium.
Neither unfractionated heparin nor tinzaparin sodium have
intrinsic fibrinolytic activity; therefore, they do not lyse
existing clots. Tinzaparin sodium induces release of tissue factor
pathway inhibitor, which may contribute to the antithrombotic
effect. Heparin is also known to have a variety of actions that are
independent of its anticoagulant effects. These include
interactions with endothelial cell growth factors, inhibition of
smooth muscle cell proliferation, activation of lipoprotein lipase,
suppression of aldosterone secretion, and induction of platelet
aggregation. (From FDA Label)