Other uses for this medicine This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information. Treatment for PE is different, and we can help with that too. Sildenafil usually should not be taken more than once every 24 hours. Do not mix the liquid with other medications or add anything to flavor the medication. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. How to take tablets Swallow tablets whole with a drink of water or juice but not grapefruit juice.Dizziness, headache, flushing, or stomach upset may occur. Vision changes such as increased sensitivity to light, blurred vision, or trouble telling blue and green colors apart may also occur. If. Viagra Connect is the first erectile dysfunction medicine in Ireland to be sold without the need for a prescription, which means you can buy Viagra Connect discreetly in store . Is there anything over the counter that works like Viagra? Many over-the-counter (OTC) treatments, including herbal supplements, claim to be able to treat ED, but none of these .