Substance
What not to mix with Opioids
OpioidDrug class
Also calledopiate, opiates, opioid, heroin, dope, smack
Full agonists — heroin, oxycodone, morphine
Summary
Opioids is checked against 40 other substances — 13 dangerous, 3 unsafe and 8 caution.
Dangerous
13- Opioids and AlcoholEach makes the other stronger, and together they can knock you out without warning. Do not combine. Keep naloxone nearby, and put anyone who passes…
- Opioids and BenzodiazepinesTogether they can slow or stop breathing and knock you out very quickly. Do not combine. Keep naloxone nearby, and put anyone who passes out on their…
- Opioids and CocaineCocaine hides how much the opioid is slowing you down, so you take more; when the cocaine wears off first, breathing can stop. Do not combine. Keep…
- Opioids and CodeineCodeine adds a lot of slowed breathing for very little extra effect. Do not combine. Keep naloxone nearby.
- Opioids and DXMTogether they slow breathing and strain the heart and liver, and DXM makes the opioid hit harder. Do not combine. Keep naloxone nearby.
- Opioids and FentanylYour tolerance to heroin or pills does not carry over cleanly to fentanyl, which is increasingly what is in both anyway. Do not combine. Never use…
- Opioids and GHB / GBLEach makes the other much stronger, fast and unpredictably, so people pass out quickly. Do not combine. Keep naloxone nearby, and put anyone who…
- Opioids and KetamineTogether they can cause vomiting and unconsciousness. Do not combine. Keep naloxone nearby, and put anyone who passes out on their side.
- Opioids and KratomKratom's ceiling does not protect you once heroin or oxycodone is on board, and a second opioid is almost always found in kratom deaths. Do not…
- Opioids and MethadoneMethadone is still there whether you feel it or not, and it blunts other opioids, so people take more of them. Do not combine. Keep naloxone nearby.
- Opioids and MXEMXE can make the opioid hit harder. Do not combine. Keep naloxone nearby.
- Opioids and PregabalinHigh risk of death or life-changing injury. Do not combine.
- Opioids and TramadolTramadol raises the seizure risk, and together they can slow breathing. Do not combine. Keep naloxone nearby.
Unsafe
3- Opioids and BuprenorphineBuprenorphine on top of a full opioid can throw you into sudden, severe withdrawal; the other way round, chasing past it leads to overdose. Avoid…
- Opioids and DiphenhydramineEach makes the other stronger, raising the risk of memory loss, collapse and unconsciousness. Avoid this combination. Keep naloxone nearby.
- Opioids and MethamphetamineMeth hides how much the opioid is slowing you, and when it fades, everything you redosed hits at once, often as you fall asleep. Avoid this…
Caution
8- Opioids and AcetaminophenMany opioid pills already contain acetaminophen, so extra Tylenol can take you past the daily limit of about 4 g. Check the label and count every…
- Opioids and AmphetaminesThe stimulant hides how much the opioid is slowing you; if it wears off first, breathing can stop. Take less of each than usual, do not use alone…
- Opioids and LithiumTogether they add sedation, and dehydration can push lithium levels up. Keep up water, and keep naloxone nearby.
- Opioids and MAOIsWith certain opioids, MAOIs have caused rare but severe and fatal reactions. Take less of each than usual, do not use alone, and keep naloxone nearby.
- Opioids and MelatoninMelatonin deepens the opioid's sedation and makes an overdose look like falling asleep. Do not use alone, and keep naloxone nearby.
- Opioids and MephedroneThe stimulant hides how much the opioid is slowing you; if it wears off first, breathing can stop. Take less of each than usual, do not use alone…
- Opioids and Nitrous OxideEach makes the other stronger, so you can lose balance or pass out without warning. Take less of each than usual, do not use alone, and keep naloxone…
- Opioids and PCPPCP can lower your opioid tolerance, making an overdose more likely. Take less opioid than usual, do not use alone, and keep naloxone nearby.
Low / synergy
1Low / no synergy
15Checking more than one?
This page rates Opioids against one substance at a time. Combinations of three or more carry risks that no pair-by-pair list can show — the checker rates every pair at once and flags the whole-mix ones on top.
Open Opioids in the checkerOther opioids
All combinations →Educational information only, not medical advice. Absence of a documented interaction is not evidence of safety. Combination data from the TripSit drug combination chart, retrieved 2026-08-20.