Activates antithrombin which then inhibits clotting factors thrombin and factor Xa

Activates antithrombin but due to shorter length preferentially inhibits factor Xa

reduced due to endothelial binding (SC), IV

up to 90% via SC (greater than heparin)

very high protein binding.

less prot bind than heparin

Vd 0.05-0.1L/kg

Vd ~ 0.1L/kg

By heparinases in the liver,
reticuloendothelial system and kidneys

Hepatic depolymerisation and desulfation to less active fragments

urine as inactive metabolites, little change in renal failure

urine as 40% of dose and 10% active fragments, dose adjustment in renal failure

variable half life due to protein binding 30 - 150 mins depending on dose

2-4 times longer half-life than heparin
dose independent half time

Bleeding, Heparin Induced Thrombocytopaenia, Osteoporosis,
Transient transaminitis

Bleeding
Needs adjustment in renal failure
Less HITS and osteoporosis

Anticoagulants

Anticoagulants

1. the prevention of venous thromboembolic disease
2. the priming of haemodialysis and cardiopulmonary bypass machines
and for maintaining the patency of indwelling lines and the treatment of
3. DIC
4. fat embolism, and
5. in the treatment of acute coronary syndromes.

1. the prevention of venous thromboembolic disease
2. the treatment of acute coronary syndromes.

Heparin is an anioic, mucopolysaccaride,
organic acid. It occurs naturally in the liver and mast cell granules.

MW: 5000-25000 Daltons

Enoxaparin is a LMWH prepared from
unfractionated heparin by controlled
enzymatic or chemical depolymerisation
Consists of smaller fragments of
Heparin. MW: Average of 5000 Daltons

Level 1

Level 1

s/c or i.v. - I.U. (not mg) due to variable potencies. 5000IU BD s/c or 5000IU IV then infusion-rate based on wttitrated (APTT)

Usually s/c, but can be given i.v.
20mg or 40mg BD s/c as prophylaxis, 1mg/kg BD s/c as therapeutic dose

Monitor:
Anti-Xa level

Reversal:
Protamine by slow infusion (1mg/100i.u.
heparin). Cationic compound forms a stable covalent salt with heparin

Reversal:
Protamine by slow infusion
Less e¬ffective than heparin due to the preferential Xa action (1mg/1mg
LMWH), but max effect is < 60%