What coffee can teach you about how drugs work

Caffeine as a gateway drug, part one

How much do you know about the substances you put into your body? Photo by danilo.alvesd on Unsplash

At some stage this week you’re probably going to use some sort of substance that acts like a drug. It could be a herbal product, a traditional or bush medicine. Possibly something illicit…or perhaps a legal ‘lifestyle’ type drug like nicotine or alcohol.

Day in day out we use substances that act as drugs. But how much do you know about them? What happens in your body as a result? How other things in the your life impact how they work?

In this Caffeine as a Gateway Drug series, we’ll go on a deep dive to learn about how drugs work. I’ll explain the key principles and introduce some of the terminology and concepts that are useful to to be familiar with if you’d like to extend your knowledge further.

I’m going to keep the articles as plain language as possible, trying to walk the line between not expecting you to have any former scientific knowledge without being condescending or over simplified.

If the way your body works isn’t something you’ve ever really thought about much before, you might like to check out my article Bodily logistics first – this covers the fundamentals of what happens to the things (including drugs) we swallow.

Bodily logistics

Here’s the full list of what’s covered by this series:

• Part 1 (this post)- general introduction

• Part 2 - dose, formulation, route of administration, absorption

• Part 3 - well, this was a bit of a rant, but covered dose-effect relationship, local vs systemic effects

• Part 4 - pharmacology of drug-receptor interactions

• Part 5 - metabolism and pharmacokinetic drug-drug interactions

• Part 6 - physicochemical drug interactions

• Part 7 - pharmacodynamic drug interactions

• Part 8 - drug elimination

• Part 9 - putting all the pharmacokinetics together

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Why caffeine?

Well, it’s a drug that’s used pretty commonly throughout the world so I think most people would be familiar with it. The way it works and is processed in the body means it provides a good illustration of almost all the important concepts of how drugs work, including why some drugs make your pee smell funny. And it’s the drug I’ve got the most lived experience with. Starting as a kid really.

You see, Christmas in Adelaide Australia can be hot. So our Christmas lunch dessert wasn’t hot pudding with custard, it was an ice cream dessert. One of those recipes my Mum got from a glossy women’s magazine that involved mixing all sorts of things to transform a store bought tub of vanilla ice cream into layers of deliciousness. This particular creation had three layers, and my favourite by far was the middle coffee one. It started me off on my love of iced coffee.

Now, iced coffee is a bit of an institution in South Australia. It has icon status. In 2008 it outsold coca-cola 3:1. Don’t picture anything fancy, I’m talking about a coffee flavoured milk drink in a carton complete with loads of sugar. It’s lovingly nicknamed Bogan Juice, so definitely not classy.

This was as far as my coffee consumption went until my early 20s. One lunch break on a hot day I got an iced coffee from a nearby Café. It was an iced double shot of espresso with a splash of milk and a scoop of coffee gelato for sweetness.

I was buzzing for the remainder of the day, super alert. My heart was racing. I felt a bit uneasy and agitated. I think I might have even been breathing better. The frequency of toilet breaks that afternoon was much higher than usual, for sure.

What was in this iced coffee? Why was I experiencing all these effects?

That’s what we’re going to unpack in these articles. Along with some other interesting bits, like how my experience might have been different if I was a smoker and why wouldn’t I feel them the same way if I drank that same drink once again twenty years later. By the end of this series you’ll understand the first principles and key concepts of how drugs work.

In part two we’ll kick off with the physical nature of things, looking at why physical form (formulation) and method of getting the drug into the body (route of administration) are important.