Cocaine and the Heart

By |September 28th, 2019|Blog|1 Comment

Cocaine is purported to be the most potent stimulant of natural origin and is extracted from the leaves of the coca plant which is indigineous to the andean highlands of south america. It is a highly addictive and once someone uses it, it causes an irresistable craving in the user to use it again. Despite the ecstacy and euphoria, it never gives a feeling of satisfaction.

Pure cocaine was first isolated in the 1880s and it was first used as an anaesthetic in eye surgery. The property that made it particularly useful with this regard was two-fold. The first was that it provided an anesthetic effect by blocking pain signals to the brain and the second was that it seemed to cause blood vessels to constrict and thereby limit bleeding. It became a recreational drug in the 1970s.

Cocaine is well absorbed following contact with the oral, nasal, gastric, rectal, vaginal and lungs when it is inhaled. Because of its vasoconstrictive properties, the rate of absorption is prolonged and therefore there is a delay in its peak effect. The bioavailability is 90% when smoked and 80% after intranasal use. Bioavailability is less when it is ingested.

When it is taken in intravenously or smoked, it acts in less than one minute, has a peak action within 3-5 minutes and acts for about 30-60 minutes.

When it is sniffed, it acts in about 1-5 minutes, has a peak action in about 20-30 minutes and lasts for 1-2 hours

When it is taken in orally, it works in 30-60 minutes, has a peak action in 60-90 minutes

It is worth noting that cocaine levels in the body and higher for longer when cociane is taken with alcohol.

Cocaine’s main effect is that it increases our sympathetic activity (flight or fight system) by increasing the amount of adrenaline, noradrenaline, dopamine and serotonin in the blood and therefore causing an exaggerated and prolonged activation of our sympathetic system. With regards to the heart, cocaine causes an increase in the heart rate and the blood pressure. Because it has the effect of narrowing the arteries, it can increase the narrowing in the heart arteries. This is also why the blood pressure goes up. What this means is that the user has a horrendous double whammy – the heart is made to ask for more blood and the blood flow is choked at the same time! Imagine trying to pressing down on the accelerator of your car with all the force that you can and blocking the pipe that takes the fuel to the engine at the same time. Imaging how damaging that is to the engine and how easily then engine can break down in that scenario.

Another problem with this scenario is that it promotes stagnation of blood and therefore blood clots can form within the vessels which can then make everything worse. In this case, the heart can start suffocating as it does so it can go into funny heart rhythm disturbances which then make everything worse can prove fatal. In addition cocaine can also with interfere directly with the sodium and potassium channels in the heart and cause QT prolongation thereby predisposing patients to dangerous dysrhtythmias.

What we also know is that the effects of regular cocaine use can become chronic. Because of all the stress that the blood vessels take during cocaine use, it can cause permanent damage to the blood vessels and this damage firstly remains even after the person has stopped using cocaine and secondly can predsipose patients to accelerated atherosclerosis as they get older or develop other comorbidities.

Studies have shown that cocaine users have more more muscular and fibrotic hearts than non users. In addition cocaine users have 4 fold greater prevalence of coronary disease and calcium compared to non users.

It is therefore incredibly important for young people who use cocaine to know exactly how damaging this habit can be and that the effects may remain to haunt them for the rest of their lives even if they decide at some stage to stop abusing this agent.

 

I hope you found this useful and would be really interested in your comments and thoughts.

Here is a video I have done on this subject

Here is an interesting reference for this subject

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6387265/

Tags: Cocaine; coronary spasm, heart attacks, sudden cardiac arrest

About the Author:

Dr Sanjay Gupta
I'm Dr Sanjay Gupta, a Consultant Cardiologist with specialist interest in Cardiac Imaging at York Teaching Hospital in York, UK. I believe that high quality reliable jargon-free information about health should be available at no cost to everyone in the world.

One Comment

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    Lynne Speight 2nd October 2019 at 3:15 pm - Reply

    Having experienced the effects of cocaine on the heart accidentally, I cannot understand why you would repeat it! I suffered a very bad reaction to a local anaesthetic of lignocaine and adrenaline given by a dentist. Within seconds of the injection I felt the most excruciating heart pain with tightness like having your heart in a vice. My resp rate shot up. This lasted about 10 mins and was followed a period of chest discomfort/stinging and, as you describe, several days of arrhythmias. I have suspected coronary vasospasm already but this was something else, not at all a pleasant experience!

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