Heparin
Brand names Calciparine, Minihep, Monoparin, Multiparin, Uniparin; [LMWH] Clexane, Fragmin, Innohep.
Used in the following combined preparations None
GENERAL INFORMATION
Heparin is an anticoagulant that is used to prevent the formation and aid in the dispersion of blood clots. Because the drug acts quickly, it is particularly useful during emergencies, for instance, to prevent further clotting when a clot has already reached the lungs or the brain. people undergoing open heart surgery or kidney dialysis are also given heparin to prevent clotting. A low dose of the drug is sometimes given to people after surgery to prevent clots from forming in leg veins (i.e., deep vein thrombosis). Often, heparin is given in conjunction with other slower-acting anticoagulants, such as warfarin, until they reach their full beneficial effects.
Its most serious adverse effect, as with all anticoagulants, is the risk of excessive bleeding, so the ability of the blood to clot is watched very carefully while the patient is kept under medical supervision. Bruising may occur around the site of the injection.
A new form of heparin called “low molecular weight heparin” (LMWH) may be more effective in preventing blood clots after orthopaedic surgery.
QUICK REFERENCE
Drug group Anticoagulant
Overdose danger rating High
Dependence rating Low
Prescription needed Yes
Available as generic Yes
INFORMATION FOR USERS
This drug is given only under medical supervision and is not for self-administration.
How taken
Injection.
Frequency and timing of doses
Every 8-12 hours (continuous intravenous infusion); LMWH once daily (prevention only).
Dosage range
Treatment 5,000 units initially, followed by
40,000 units over 24 hours.
Prevention 5,000 units subcutaneously.
Onset of effect
Within 15 minutes.
Duration of action
4-12 hours after treatment is stopped.
Diet advice
None.
Storage
Not applicable; this drug is not kept in the home.
Missed dose
Notify your doctor.
Stopping the drug
Do not stop taking the drug without consulting your doctor. Stopping the drug may lead to clotting of blood.
OVERDOSE ACTION
Seek immediate medical advice in all cases. Take emergency action if bleeding, severe headache, or loss of consciousness occur. Overdose can be reversed under medical supervision by a drug called protamine.
See Drug poisoning emergency guide.
POSSIBLE ADVERSE EFFECTS
As with all anticoagulants, bleeding is the most common adverse effect with heparin.
The less common effects may occur during long-term treatment.
INTERACTIONS
Aspirin
Do not take aspirin, which may increase the anticoagulant effect of this drug and the risk of bleeding in the intestines or joints.
Dipyridamole
The anticoagulant effect of heparin may be increased when taken with this drug. The dosage of heparin may need to be adjusted accordingly.
SPECIAL PRECAUTIONS
Be sure to tell your doctor if:
You have long-term liver or kidney problems.
You have high blood pressure.
You bleed easily.
You have any allergies.
You have stomach ulcers.
You are taking other medications.
Pregnancy
Careful monitoring is necessary as it may cause the mother to bleed excessively if taken near delivery. Discuss with your doctor.
Breast-feeding
No evidence of risk.
Infants and children
Reduced dose necessary according to age and weight.
Over 60
No special problems.
Driving and hazardous work
Avoid risk of injury, since excessive bruising and bleeding may occur.
Alcohol
No special problems.
Surgery and general anaesthetics
Heparin may need to be stopped. Discuss this with your doctor or dentist before having any surgery.
PROLONGED USE
Osteoporosis and hair loss may occur; tolerance to heparin may develop.
Monitoring
Periodic blood checks will be required.
