Before prescribing hirudotherapy, it is necessary to examine the accumulated tissue to ensure the presence of venous stasis and not arterial insufficiency. Drugs that increase the risk of bleeding or decrease the immune response should be reconsidered, and patients should avoid caffeine until therapy is completed to reduce the risk of vasoconstriction.
Smoking and the use of nicotine replacement products are contraindicated during therapy due to the vasoconstrictor effects of carbon monoxide and nicotine.
...Contraindications to treatment with leeches:
Arterial insufficiency
Previous allergic reaction to leeches
Unstable medical status
Immunosuppression (eg, HIV infection, concurrent chemotherapy)
If the patient refuses to accept a blood transfusion if it is needed (for example, for religious reasons)
If the patient refuses to consent to treatment with leeches