I’ve just discovered Instacast, an app that makes it astonishingly easy to subscribe to and follow podcasts on an iPhone or iPad. Subscriptions are entered by touching one button, podcasts can be streamed or downloaded for off-line viewing, show notes can be browsed or followed while listening to or watching a podcast. Instacast makes the iPhone — and especially the iPad — an amazingly versatile medical education tool. It has quickly become my favorite app of all time. It is available from the iTunes app store for $1.99. Instacast HD for the iPad — with added functionality — is $4.99.

[Full disclosure: I have absolutely no association -- financial or otherwise -- with Instacast or Vemedio. I just love Instacast.]

Here are the medical podcasts I subscribe to:

• EMCrit - Scott Weingart’s brilliant and entertaining discussion of topics that “bring upstairs care downstairs”, covering intensive care principles that are essential to the practice of emergency medicine.
• Emergency Ultrasound Podcast - Mike Mallon and Matt Dawson break down even complex subjects like diastolic dysfunction and make them clear. The lectures have great illustrations and cases. I can’t imaging anyone interested in emergency ultrasound who would not want to view every episode. For a taste, check out the post about cardiac wall motion abnormalities. By the way, this podcast looks great on the iPad.
• ERCast - Rob Orman and guests discuss important topics in emergency medicine. Recent podcasts have covered pediatric fever, RLQ pain in pregnancy, and spinal tap following a negative CT in suspected subarachnoid hemorrhage.
• The Journal of Medical Toxicology Podcast — Each month, Drs. Howard Greller and Daniel Rusyniak review the current issue of J Med Toxicol.
• Free Emergency Medicine Talks – This is an amazingly comprehensive set of lectures selected and posted by Joe Lex. Need I say more?
• ToxTalk – Discussion from the toxicology service at the University of Massachusetts.
• Smart EM – Drs. David Newman and Ashley Shreves provide in-depth discussion of focused questions in emergency medicine. Their episode about the recent NEJM article on acute otitis media in children was one of the most spectacular dissections of a medical paper I’ve ever heard.
• EMRAP: Educators’ Edition – Rob Rogers, Amal Mattu, Mel Herbert and guests discuss all things related to medical education and academics.

For a comprehensive set of links to emergency medicine and toxicology blogs, see this database at Life in the Fast Lane.

Life is not all emergency medicine. Here is a list of my non-medical subscriptions on Instacast:

TED Talks

NPR: Fresh Air

NPR: Wait Wait . . . Don’t Tell Me

This American Life

The Extension 720 Podcast

KCRW’s Morning Becomes Eclectic

Clinical toxicology of newer recreational drugs. Hill SL, Thomas SHL Clin Toxicol 2011;49:705-719. 

Abstract

This essential article will probably be of most interest to chemical structure geeks (like me) and academics, but it is the best review I know that gets granular about the pharmacology of the many new designer drugs.

The authors did a comprehensive review of published medical literature involving new designer drugs. (Synthetic cannabinoids, synthetic cocaine , and GHB are not covered.) They classify these drugs into four categories:

1. piperazines
2. phenethylamines
3. tryptamines
4. piperidines

Piperazines are synthetic chemicals that do no exist in nature. Included in this group is BZP, a sympathomimetic stimulant with effects similar to those of amphetamine.  BZP inhibits re-uptake of dopamine and norepinephrine.

Phenethylamines include amphetamine, methamphetamine, and MDMA (ecstasy). Other examples are the synthetic cathinone mephedrone, MDPV (commonly found in “bath salts”), bromodragonFLY, and the 2C series.  Phenethylamines are predominantly sympathomimetic stimulants, but can have varying degrees of psychoactive and hallucinogenic properties created by substitutions on the basic molecule.

Tryptamines are derived from the amino acid tryptophan. Examples include psilocybin, LSD and DMT (a component used by Ayahuasca shamans). Tryptamines are primarily hallucinogenic rather than entactogenic or stimulant.

Piperidines include desoxypipradrol (2-DPMP), a component of the designer drug “whack”. It has also been found recently in products sold as “Ivory Wave” bath salts. Piperidines are stimulants that can cause prolonged psychotic effects.

This classification scheme is very helpful in thinking about designer drugs, but has limited clinical usefulness. In fact, when dealing with a patient who has been acutely exposed to a designer drug, the clinician is never certain exactly what chemical or chemicals are involved. Street products can contain a mixture of ingredients. Therefore, there are few specific recommendations regarding medical management in this paper. The authors’ approach can be summed up by their last sentence:

The management of users with acute toxic effects is pragmatic and, in general, as for poisoning with longer established stimulant or hallucinogenic drugs such as amphetamines and MDMA.

With 169 references through 2011, this article should be in the files of anyone with more than a passing interest in the science of designer drugs.

Related posts:

“Party pills”: review of BZP and TFMPP

 CBS News reports on the designer drug 2 C-E and the death of a Minnesota teenager

Mephedrone review

Confirmed mephedrone-associated fatality

How does the body handle mephedrone and other designer drugs?

Mephedrone (meow-meow): first confirmed report 

Nexus (2C-B) associated with Significant Cerebral Vasospasm 

Ayahuasca – a pharmacologically fascinating psychedelic brew 

From pre-trial hearings and yesterday’s opening arguments in court, it is apparent that the defense team for Dr. Conrad Murray — the physician accused of manslaughter in the death of Michael Jackson — plans to argue that Jackson administered the fatal dose of propofol to himself, possibly by swallowing it. This contention is certainly based in part on the forensic toxicology report, which showed 0.13 mg of propofol in the singer’s gastric contents.  It is unclear from the report whether this is a total amount or is based on volume.  Interestingly, lidocaine was also found in the gastric contents.  Lidocaine is often administered with propofol to prevent burning, but this would obviously be unnecessary if the drug was ingested (unless it was pre-mixed). To my knowledge, there are no studies showing to what extent, if any, propofol might undergo postmorten redistribution, with leakage of the drug from the circulatory system into stomach contents.

Apparently the prosecution has retained an expert witness who is expected to testify that it would have been impossible for Jackson to have swallowed the fatal dose.

This trial involves many fascinating toxicology issues.  TPR will follow developments closely.  The trial itself is being televised in its entirety on HLN.

Related posts:

Propofol effects, blood levels, and abuse

Propofol as a drug of abuse

Michael Jackson toxicology report released

Abstract

The title of this article grossly overstates what it contains.  It is a retrospective review of “bath salt” exposure not in the “United States”, but rather as reported to two state-wide poison control centers (Kentucky and Louisiana). It does not really describe direct “clinical experience”, but instead data reported to and recorded by the regional poison control centers. (The calls came both from medical professionals and the lay public.) And “analytical confirmation” occurred in just a small minority of patients. Nevertheless, the paper is well worth reading, especially since there’s still not much medical literature related to the “bath salt” phenomenon. The authors retrospectively reviewed records from a computerized database to identify calls related to “bath salts” received by the two poison control centers over a period of approximately 1 year (January 2010 through February 2011). It is not clear to me what methods were used to confirm that each case actually represented bath salt or synthetic cathinone exposure. They found 236 cases, 22% of which represented calls from the general public. Clinical effects were predominantly cardiovascular and neurological, consistent with the sympathomimetic toxidrome, with a high incidence of aggressive violent behavior, hallucinations, and paranoia. The paper also describes cases of alarmingly dangerous behavior:

Examples of these new onset behaviors in separate patients included: jumping out of a window to flee from non-existent pursuers; requiring electrical shock (Taser) and eight responders to initially subdue the patient; repeatedly firing guns out of the house windows at “strangers” who were not there; walking into a river in January to look for a friend who was not there; leaving a 2-year-old daughter in the middle of a highway because she had demons; climbing into the attic of the home with a gun to kill demons that were hiding there, and breaking all the windows in a house and wantering barefoot through the broken glass.

There was one death: a 21-year-old man shot himself during a delusional episode. This seems to be the well-known tragic case of Dickie Sanders described in the following piece from NBC’s Today show:

www.youtube.com/watch?v=TlorzOfCNb4

Blood and/or urine tests for synthetic cathinones were carried out on samples from 19 patients; the only psychoactive stimulant detected was MDPV. In addition, 15 “bath salt” products were obtained and tested, all of which contained MDPV, mephedrone, and/or methylone.

It’s always important to keep in mind that “bath salts” and “legal highs” are moving targets, as suppliers attempt to stay one step ahead of the law and specific substances are increasingly being banned by state legislatures.  However, management of patients presenting with a sympathomimetic toxidrome does not depend on what specific stimulant they’ve been exposed to, and is based on principles outlined in a recent letter in the New England Journal of Medicine.

Click here to reveal the 39 different product names reported by users

Related posts:

New England Journal of Medicine on “Bath Salts”

New York Times on Bath Salts

NBC’s Dateline goes undercover to investigate the “bath salt” industry

“Bath salts” in Michigan

Were “bath salts” involved in a double murder/suicide in Washington State?

Dr. Oz on bath salts (MDPV)

NBC’s Today Show reports on bath salts (MDPV)

Death in Britain: “Ivory Wave” (MDPV) or diabetic ketoacidosis

“Ivory Wave” identified as MDPV

It’s not your mom’s bath salts

To read my Emergency Medicine News column on bath salts, click here.