WARFARIN (COUMADIN, JANTOVEN, GENERIC)
WARNING: Can cause major/fatal bleeding. Monitor INR. Drugs, dietary changes, other factors affect INR. Instruct pts about bleeding risk.
USES: *Prophylaxis & Treat of PE & DVT, AF w/ embolization*, other postop indications.
ACTIONS: ↓ Vit K-dependent clotting factors in this order: VII-IX-X-II.
DOSE:
Adults: Titrate, INR 2.0–3.0 for most; mechanical valves INR is 2.5–3.5. American College of Chest Physicians guidelines: 5 mg initial, may use 7.5–10 mg; ↓ if pt elderly or w/ other bleeding risk factors; maint 2–10 mg/d PO, follow daily INR initial to adjust dosage.
Peds: 0.05–0.34 mg/kg/24 h PO or IV; follow PT/INR to adjust dosage; monitor vit K intake; ↓ w/ hepatic impairment/elderly.
W/P: [X, +].
CI: Bleeding, peptic ulcer, pregnancy.
DISP: Tabs 1, 2, 2.5, 3, 4, 5, 6, 7.5, 10 mg; Inj.
SE: Bleeding d/t over anticoagulation or injury & therapeutic INR; bleeding, alopecia, skin necrosis, purple toe syndrome.
NOTES: Monitor vit K intake (↓ effect); INR preferred test; to rapidly correct overanticoagulation: vit K, fresh-frozen plasma, or both. Caution pt on taking w/ other meds that can ↑ risk of bleed. Common warfarin interactions: Potentiated by: Acetaminophen, EtOH (w/ liver disease), amiodarone, cimetidine, ciprofloxacin, cotrimoxazole, erythromycin, fluconazole, flu vaccine, isoniazid, itraconazole, metronidazole, omeprazole, phenytoin, propranolol, quinidine, tetracycline. Inhibited by: Barbiturates, carbamazepine, chlordiazepoxide, cholestyramine, dicloxacillin, nafcillin, rifampin, sucralfate, high–vit K foods. Consider genotyping for VKORC1 & CYP2C9.
WITCH HAZEL (TUCKS PADS, OTHERS [OTC])
USES: After bowel movement, cleansing to decrease local irritation or relieve hemorrhoids; after anorectal surgery, episiotomy, Vag hygiene.
ACTIONS: Astringent; shrinks blood vessels locally.
DOSE: Apply PRN.
W/P: [?, ?] External use only.
CI: None.
SUPPLIED: Presoaked pads.
SE: Mild itching or burning.