What's Safe on PrEP?

Pharmacist Drew shares what medications and herbal products can interact with PrEP

What Not to Mix

Did you know something common in our medicine cabinets might not be safe while on PrEP?

Anti-inflammatories like ibuprofen (Advil) and naproxen (Aleve) can affect our kidneys and this risk may be increased while taking PrEP.

Generally, rare occasional use of anti-inflammatories while on PrEP should be okay in individuals in general good health (eg. a person goes in for dental work and takes a day or two of them). 

However, more frequent or regular use is not typically recommended and should be closely monitored if being taken together. Acetaminophen (Tylenol) is usually preferred for pain and fever. 

Valacyclovir, sometimes used for herpes management, has a potential interaction with PrEP but can be safely combined when monitored appropriately.

What else should I know about?

Not Expected to Interact
With PrEP

This information is for
educational purposes only.
  • MDMA / Molly / Ecstasy, cocaine, crystal meth
  • ED Meds (eg. Viagra, Cialis)*
  • Cannabis
  • Alcohol
  • Poppers

Not Recommended
While on PrEP

Speak to your care provider about the
appropriateness of combing these.
  • Ongoing or regular anti-inflammatory use
  • Some anti-seizure medication*
  • Some prescription antifungals*
  • St John's Wort*

Can I take supplements while on PrEP?

Many supplements can be combined safely with PrEP. However, it is important to let your care provider know if you will be taking creatine or protein supplements. While generally safe, these may affect the results from routine PrEP lab test results.

One of the regular blood tests while on PrEP measures the level of creatinine in your blood and provides an estimate of how well things are clearing from the kidneys. This is known as the eGFR (estimated glomerular filtration rate). Supplements can potentially make it appear your kidneys are not clearing things as well, even when they are working normally.

Always let whoever is prescribing and monitoring your PrEP medication know what you are taking so they can best interpret lab results.

What Not to Mix with Descovy

If you’re taking the newer formulation of PrEP (Descovy) you should also be aware that the common herbal product St. John’s Wort should not be combined with it. This herbal is sometimes used for mild to moderate depression but when combined with PrEP may decrease its ability to protect against HIV. Some data suggests lower strengths of St. John’s Wort may be okay, but generally it is not recommended. If your care provider has started you on this you should follow-up with them.

In terms of prescription medication, some seizure medications and antifungals are not safe to take with this version of PrEP. 

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