Antiplatelet and anticoagulant drugs (blood-thinners) -- Stinging nettle may affect the blood's ability to clot, and could interfere with any blood-thinning drugs you are taking, including:

• Warfarin (Coumadin)
• Clopidogrel (Plavix)
• Aspirin

Drugs for high blood pressure -- Stinging nettle may lower blood pressure, so it could make the effects of these drugs stronger:

• ACE inhibitors: Captpril (Capoten), Elaropril (Vasotec), lisinopril (Zestril), fosinopril (Monopril)
• Beta blockers: Atenolol (Tenormin), metoprolol (Lopressor, Toprol XL), propranolol (Induran)
• Calcium channel blockers: Nifedipine (Procardia), amlodipine (Norvasc), verapamil (Calan, Isoptin)

Diuretics (water pills) -- Because stinging nettle can act as a diuretic, it can increase the effects of these drugs, raising the risk of dehydration:

• Furosemide (Lasix)
• Hydrocholorothiazide

Drugs for diabetes -- Stinging nettle may lower blood sugar, so it could make the effects of these drugs stronger, raising the risk of hypoglycemia (low blood sugar).

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) -- In a scientific study of patients with acute arthritis, stewed stinging nettle leaves enhanced the anti-inflammatory effect of diclofenac, an NSAID. Although the effect can reduce pain, you should talk to your doctor before taking or using stinging nettle if you also take NSAIDs.