Erectile Dysfunction Agents (Sildenafil, Tadalafil and Vardenafil)

Erectile dysfunction agents are frequently used with recreational substances in the context of ‘chemsex’ which can increase risk of adverse effects (Giorgetti et al., 2017).

Physiologically, erectile dysfunction agents improve blood circulation to the penis, but the user must be sexually aroused for an erection to occur (Jewell, 2020).

The effects of erectile dysfunction agents may vary depending how much of the substance has been used and frequency of use within a certain timeframe (Jewell, 2020). Other factors that can impact the effects of erectile dysfunction agents include:

•       Individual factors (e.g., age, weight, diet, comorbidities).
•       Environmental factors (e.g., the setting/location).
•       Drug interactions.

Serious adverse effects of erectile dysfunction agents can occur when large amounts of the substance have been used within a short timeframe. Generally, doses should not exceed 100mg within a 24 hour period (Jewell, 2020) The most common adverse effect is priapism which is a painful erection that lasts longer than 4 hours (Jewell, 2020). Adverse effects may be more likely to occur when erectile dysfunction agents are used without seeking medical advice prior to use (Giorgetti et al., 2017).

Erectile dysfunction agents are administered orally in pill or tablet form but can be injected intracavernously (at the base of the penis) usually administered by a medical professional (Steers, 2002). When erectile dysfunction agents are ingested, the effects can be experienced within 30 minutes and usually last for 2-3 hours (Jewell, 2020).

When erectile dysfunction agents are purchased from an online source without medical guidance the substance may be mixed with other unknown substances, increasing risk of adverse effects (Giorgetti et al., 2017).

Prescribed Substances

Erectile dysfunction agents may produce serious and life-threatening adverse effects when used with certain HIV medications and blood pressure medications.

HIV Medications

• Ritonavir and Cobicistat are used to boost the availability of other substances (primarily other HIV medications) in the body by decreasing the breakdown speed of these substances.
• Ritonavir and Cobicistat interact with erectile dysfunction agents by increasing the availability of erectile dysfunction agents in the body, leading to adverse effects (Bracchi et al., 2015).
• There is potential for other HIV-medications to interact with erectile dysfunction agents.

Blood Pressure Medications

• Nitrates are a form of blood pressure medication that can cause serious and/or life-threatening adverse effects when used with erectile dysfunction agents (MedlinePlus, 2021).

Other prescription medications are known to interact with erectile dysfunction agents (MedlinePlus, 2021). Users should seek medical advice regarding their erectile dysfunction agent use if they take the following medications:

• Blood thinners.
• Anti-seizure medication.
• Herbal products such as St. John’s Wort.

Recreational Substances

When erectile dysfunction agents are used with recreational substances, this can alter the intended effects of certain substances and increase risk of adverse effects.

Amyl Nitrates (Poppers)

• Using erectile dysfunction agents with poppers can cause a sudden and dramatic decrease in blood pressure (Giorgetti et al., 2017).