Heparin (UFH) | Drug Overview & Clinical Reference
Heparin (UFH)
Clinical safety rating: safe
Human studies have proved safety
How it works
Mechanism information is still being processed. Check the DailyMed link in the sidebar for the official prescribing information.
Dosing & administration
Dosing varies by indication and patient profile. Always follow your institution's current prescribing guidelines.
Renal impairment
Consult protocols for adjustment.
Liver impairment
Consult protocols for adjustment.
Use during pregnancy
1st trimester
Safe. Used for VTE treatment and prevention.
2nd trimester
Safe.
3rd trimester
Safe. Preferred choice from 36 weeks onward (when transition from LMWH occurs) to allow neuraxial anesthesia with appropriate washout.
Clinical note
Safe in pregnancy. Unfractionated heparin does not cross the placenta due to its large molecular size. Preferred over LMWH in specific scenarios: near delivery (allows complete reversal with protamine), in patients with renal impairment (where LMWH is less predictable), and for acute PE requiring thrombolysis or catheter-directed therapy. Requires aPTT monitoring. Long-term use associated with heparin-induced osteoporosis and thrombocytopenia (HIT); LMWH preferred for long-term use.
Breastfeeding
Safe. Large molecular weight prevents breast milk excretion; not orally bioavailable. Compatible with breastfeeding.
