# Suicide by "Methadone and Cold Medication" **URL:** \ **Category:** Factual Questions\ **Created:** [January 28, 2015, 5:42am UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085 "2015-01-28T05:42:58Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [January 28, 2015, 5:42am UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/1 "2015-01-28T05:42:58Z")
Yes, the Strack tragedy in Utah Short form: Worried about the impending Apocalypse (aka “End Times”), parents kill 3 kids and themselves with what police say was a combination of “methadone and cold medication”. Another story goes into more detail: diphenhydramine (Benadryl). He used heroin, she went with “methadone, dextrorphan, diphenhydramine and doxylamine”. The kids had to make do with just methadone and diphenhydramine. Did the antihistamine (also sold as OTC ‘Sleep Aid’) actually accomplish anything? Yes, morbid - but I guessed that one would puke before one could get close to a lethal dose. Well, I’ve put this together so I"ll finish with: Yes, there is an established LD50 for diphenhydramine in humans - and it is surprisingly small. It is listed on Pfizer’s MSDS. ---
**Author:** ![boffking](https://avatars.discourse-cdn.com/v4/letter/b/858c86/32.png) [@boffking](https://boards.straightdope.com/u/boffking)\ **Post date:** [January 28, 2015, 4:32pm UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/2 "2015-01-28T16:32:45Z")
If someone is taking just diphenhydramine, it takes a ridiculous amount to fatally OD. I knew a guy in college who liked to get high by taking 20+ benadryl at a time. Although, taking those four drugs together may have a combination effect that is much stronger. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [January 28, 2015, 6:17pm UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/3 "2015-01-28T18:17:22Z")
Antihistamines like diphenhydramine are well-known to potentiate the effects of opioids like methadone. A dose of opioid that may not be fatal for someone can become fatal when an antihistamine is taken at the same time. In addition, dextromethorphan is an opioid-type molecule with limited activity, but stacking it on top of another opioid will raise the risk of opioid overdose too. All in all, mixing heroin, methadone, destromethorphan, diphenhydramine AND doxylamine (another antihistamine) is just not a good idea. ---
**Author:** ![gigi](https://avatars.discourse-cdn.com/v4/letter/g/a587f6/32.png) [@gigi](https://boards.straightdope.com/u/gigi)\ **Post date:** [January 28, 2015, 10:28pm UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/4 "2015-01-28T22:28:29Z")
QtM, I hope you don’t mind if I ask a vaguely-related question. Can dextromethorphan be used by someone taking SSRIs? I hope this is still a GQ even though it’s me, on Lexapro. I am asking for a general answer on the combination, not medical advice. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [January 28, 2015, 10:34pm UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/5 "2015-01-28T22:34:00Z")
Taking DXM with SSRIs and similar drugs **greatly** raises the risk of experiencing Serotonin Syndrome, a nasty, often fatal condition. I can see no possible advantage worth the risk of combining those two. DXM is a crappy cough suppressant anyway. ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [January 29, 2015, 2:20am UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/6 "2015-01-29T02:20:51Z")
Maybe this is why the Lunesta started being more effective - I have a runny nose, so I added a 25mg capsule of diphenhydramine to the bedtime cocktail (Mirtazapine, MS-Contin, Lunesta, antihypertensives). The addition of the diphen is the only change, and I’m sleeping longer and more deeply (re. the “Is it Really Sleep Q” - close enough, and it’s the only one I’ve got. End discussion. ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [January 29, 2015, 2:25am UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/7 "2015-01-29T02:25:29Z")
**QtM** - is the LD50 on Pfizer’s MSDS based on anything? I’ll save the rest of you folks the trouble: is shows Human LD50 - 10.1 mg/kg for diphenhydramine hcl. This cannot be right, or I am even more of an outlier then I suspected. ---
**Author:** ![gigi](https://avatars.discourse-cdn.com/v4/letter/g/a587f6/32.png) [@gigi](https://boards.straightdope.com/u/gigi)\ **Post date:** [January 29, 2015, 3:57am UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/8 "2015-01-29T03:57:09Z")
> [@Qadgop\_the\_Mercotan](#): > > Taking DXM with SSRIs and similar drugs **greatly** raises the risk of experiencing Serotonin Syndrome, a nasty, often fatal condition. I can see no possible advantage worth the risk of combining those two. DXM is a crappy cough suppressant anyway. Thanks – I was told many years ago and wanted to make sure I remembered right. Unfortunately it means no Nyquil. ---
**Author:** ![buddha\_david](https://avatars.discourse-cdn.com/v4/letter/b/ee7513/32.png) [@buddha\_david](https://boards.straightdope.com/u/buddha_david)\ **Post date:** [January 29, 2015, 4:11am UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/9 "2015-01-29T04:11:36Z")
My cousin committed suicide with an overdose of Benadryl. So yes, it is possible. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [January 29, 2015, 4:22am UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/10 "2015-01-29T04:22:13Z")
One of the antivaxx poster children who was supposedly killed by the HPV vaccine actually overdosed on Benadryl. Don’t know how much she took, but it was enough. Sad tale. [Medical examiner: Girl's death not caused by HPV vaccination](http://www.jsonline.com/news/health/medical-examiner-girls-death-not-caused-by-routine-vaccination-b99376029z1-280058462.html) ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [January 29, 2015, 5:16am UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/11 "2015-01-29T05:16:58Z")
By this calc, a 140 lb person would need no more than 14 capsules of 50mg diphen to have a 50/50 chance of dying. How many drugs have an established LD100? (dosage at which 100% of the subjects died)? I know I’ve taken at least 4x50mg at once (I now have real sleepers). Of all the nasty drugs I’ve been prescribed, I don’t think any of the 'script meds are nearly as dangerous. ---
**Author:** ![grude](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@grude](https://boards.straightdope.com/u/grude)\ **Post date:** [January 29, 2015, 5:58am UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/12 "2015-01-29T05:58:31Z")
This story is so odd, it says the mom was on methadone but they don’t say if it was for pain or addiction treatment. So she had to have had an opiate tolerance. Apparently the dad OD’d on heroin alone, no info on what the kids OD’d on. FWIW dextorphan is not used in any pharmaceutical, but is a metabolite of dextromethorphan. Unsure why they reported it this way. EDIT:Whoops in the OP “The kids had to make do with just methadone and diphenhydramine.”. ---
**Author:** ![SpeedwayRyan](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@SpeedwayRyan](https://boards.straightdope.com/u/SpeedwayRyan)\ **Post date:** [January 29, 2015, 9:24pm UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/13 "2015-01-29T21:24:55Z")
> [@Qadgop\_the\_Mercotan](#): > > Antihistamines like diphenhydramine are well-known to potentiate the effects of opioids like methadone. A dose of opioid that may not be fatal for someone can become fatal when an antihistamine is taken at the same time. This is what I was going to post, but since I got scooped by an MD, I’m not going to add anything 🙂 ---
**Author:** ![Cornelius\_Tuggerson](https://avatars.discourse-cdn.com/v4/letter/c/13edae/32.png) [@Cornelius\_Tuggerson](https://boards.straightdope.com/u/Cornelius_Tuggerson)\ **Post date:** [January 29, 2015, 10:08pm UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/14 "2015-01-29T22:08:00Z")
> [@Qadgop\_the\_Mercotan](#): > > mixing heroin, methadone, dextromethorphan, diphenhydramine AND doxylamine… Shoot, a fella’ could have a pretty good weekend in Vegas with all that stuff. ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [January 30, 2015, 1:23am UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/15 "2015-01-30T01:23:53Z")
But I can do it only once… ---
**Author:** ![tapu](https://avatars.discourse-cdn.com/v4/letter/t/49beb7/32.png) [@tapu](https://boards.straightdope.com/u/tapu)\ **Post date:** [January 30, 2015, 1:52am UTC](https://boards.straightdope.com/t/suicide-by-methadone-and-cold-medication/711085/16 "2015-01-30T01:52:28Z")
I can’t believe I’m still alive.