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What are they?

Opioids are any drug made from or related to the opium poppy (which sounds kind of cute right?), or those that interact with the opioid receptors in the brain (not sounding so cute here though). They slow down the messages travelling between the brain and the body – basically it means that we are a few steps behind the beat. There are legal (e.g., codeine, fentanyl, morphine, oxycodone, buprenorphine, and methadone) and illegal opioids (e.g., heroin).

Opioid medications are often swallowed in tablet form. Some synthetic opioids are found in liquid, tablet and film formations (with the film forms often dissolved under the tongue). Heroin is usually injected but can be snorted or smoked. With injecting, there is risk of contracting blood borne viruses, such as hepatitis B & C and HIV if needles are shared and the risk of infection at the injecting site.

What are the effects?

Opioids facilitate the release of dopamine in the brain. Dopamine causes pain relief and feelings of relaxation and pleasure.

  • Extreme relaxation
  • Drowsiness and clumsiness
  • Confusion and slurred speech
  • Slow breathing and heartbeat.
  • Cold, clammy skin
  • Slow breathing
  • Blueish or ashen/greyish lips and fingertips
  • Falling asleep (‘going on the nod’)
  • Increased tolerance, meaning we need more to feel the same kind of high
  • Constipation
  • Vital organ damage (heart, brain, lungs)
  • Death by respiratory depression


If we take a large amount or have a strong batch of opioids, then it’s possible to overdose. They slow our breathing and heart rate – and can cause us to stop breathing altogether. The symptoms of an overdose on opioids will be different depending on what drug we are taking. Watch out for each other and call 000 in an emergency.

Naloxone is an over the counter drug used to temporarily reverse an overdose on opioids. It can be purchased at local pharmacies and anyone can administer it. It’s handy to have around, just in case!! It can be used as a nose spray or injected – and no, it’s not like Pulp Fiction! Even after naloxone has been used, medical attention should be sought immediately.

Mixing with other drugs

The effects of mixing opioids with other drugs – including over the counter or prescribed medications can be unpredictable and dangerous. Do not mix opioids with the following medications because it may increase the risk of overdose, and even death:

  • Ketamine
  • Cocaine
  • Alcohol
  • GHB
  • Benzos

To discover more about the specific interactions between alcohol and other drugs, refer to the Australian Drug Foundation

HIV Medications

The interactions between opioids and antiretroviral medications are not well known. There’s currently no evidence to suggest that opioid use directly reduces the efficacy of antiretroviral medications. If some new research comes to light, then we’ll update this section and let you know.

We did find that Nevirapine significantly increases the symptoms of opioid withdrawals, so best to chat with a healthcare professional before quitting.

The interactions between opioids and PrEP and PEP are not well known. There’s currently no evidence to suggest that opioid use directly interacts with these medications or reduces their efficacy. We’ll keep looking and update you if any new research comes to light.

To find out about specific HIV medications and their interactions with opioids head to Liverpool HIV Drug Interactions Checker.


There’s currently no evidence to suggest that opioid use reduces the efficacy of HRT. We’ll keep looking and update this information if something new comes to light.

Oestradiol can affect our opioid receptors and therefore how the body processes it, so it’s best to chat with a healthcare professional about whether our dosage needs to be adjusted.

Spironolactone and opioids can potentially lead to a build-up of toxicity and affect our kidneys.

Progesterone and Cyproterone Acetate can have sedative effects and cause tiredness and fatigue, so taking these along with other depressants may lead to feeling more exhausted during or after using opioids.

Both testosterone and opioids can cause water retention, which means we may experience constipation and bloating when taking both.

We don’t yet know enough about how opioid-induced androgen deficiency (OPIAD) may impact bodies that are taking testosterone, including whether it may impact our absorption or processing of our HRT.

For more information about opioids head to the Australian Drug Foundation

The information given on this page is not medical advice and should not be relied upon in that way.