A newer form of the medicine that dissolves on the tongue might work faster than the pill that you swallow. Kidney disease that needs to be treated with dialysis. It may be difficult to remain firm despite wanting to have sex. Those with a history of blood pressure or heart issues, hormonal imbalances, mental health issues, and diabetes should consult their doctor before trying PDE5 inhibitors. Most companies have an FAQ or shipping policy page you can reference to learn whether discreet packaging is available. However, others work on a cash-pay basis and don’t partner with insurance companies. If approved, the provider will issue a prescription.Sildenafil (Viagra). This medicine works best when you take it on an empty stomach an hour before sex. The body takes longer to absorb it after a high-fat meal or .  · a light-headed feeling, like you might pass out. Common sildenafil side effects may include: flushing (warmth, redness, or tingly feeling); headache, dizziness; .