Omeprazole uk price try not to eat grapefruit or drink grapefruit juice while you are being treated with Sildenafil. A serious allergic reaction to this drug is very rare, but seek immediate medical help if it occurs. Super P-Force cannot be used in patients with allergy to the medication and its components and also in individuals treated with nitrates (such as nitroglycerin). This combination can cause very low blood pressure potentially dangerous to result in a stroke, heart attack, or death. Do not take this medication if you are under 18 y.o.