Erectile dysfunction drugs
Sildenafil is a drug used to treat erectile dysfunction. It is prescribed under brand names such as Viagra and Kamagra.
| Other names | sildenafil citrate, Viagra |
|---|---|
| Health risk | Mild |
| Addiction risk | Mild |
| Legal risk | Mild |
Background
Medical uses
In addition to erectile dysfunction, sildenafil is used to treat pulmonary arterial hypertension (a type of high blood pressure) in men and women.[1]
Mechanism of action
Sildenafil increases blood flow (vasodilation) by inhibiting the enzyme phosphodiesterase 5 (PDE5).[2] Sildenafil and other PDE5 inhibitors do not cause erections without sexual arousal, and do not increase arousal. Sildenafil also inhibits PDE5 elsewhere in the body, particularly the lungs, and can cause systemic vasodilation.
Erections occur when spongy tissue in the penis (the corpora cavernosa and corpus spongiosum) fill with blood, expand, and become rigid. The erectile tissue is surrounded by smooth muscle that is tonically (usually) contracted, and the muscle must relax (vasodilation) for sufficient blood to enter the penis. During arousal, the body increases production of cyclic guanosine monophosphate (cGMP), a molecule that triggers smooth muscle relaxation. Sildenafil increases the amount of cGMP in the corpora cavernosa by protecting cGMP from degradation by PDE5. Sildenafil has a similar molecular shape to cGMP and can bind strongly to PDE5, blocking cGMP from entering the enzyme's active site.
Appeal
Dosing
Risks
Check the notes in the medication for side effects. Different "fillers" for tablets can have different side effects.
If it affects your blood pressure, it can make you feel spaced out and other symptoms (feeling weak, sick blurred vision, fainting), in this case you should stop further sexual and BDSM activities, and ensure you are somewhere safe in case you pass out.
If experiencing prolonged or painful erection, especially if it lasts for more than 2 hours, call emergency services[3].
Drug interactions
Addiction
Risk mitigation
Sildenafil should never be used with poppers as together they can cause fatal drop in blood pressure. It should also not be used in combination with other medicines being used to treat blood pressure.
If the user is feeling symptoms of low blood pressure:
- Seek medical attention
- Lay down
- Sitting up or standing up suddenly can worsen lightheadedness or cause fainting.
- Drink water
- Do not consume alcohol or other substances
Known incidents
Medical case reports
RACKWiki incident reports
References
https://www.nhs.uk/conditions/low-blood-pressure-hypotension/
- ↑ "Sildenafil (oral route) - Side effects & dosage". Mayo Clinic. Retrieved 2025-11-06.
- ↑ "Sildenafil". go.drugbank.com. Retrieved 2025-11-06.
- ↑ "Side effects of sildenafil". nhs.uk. 2022-03-03. Retrieved 2024-02-16.