Let's face it, there's lots to think about when people use drugs. Consider the physical and psychological effects of the drug, how much you take, what it's made from, what it's cut with, where you use it, how you use it, who you use it with, where it's sourced from, and your physical and mental health. Combine two or more drugs and it's clear that mixing meth with other drugs is a very risky practice.
There's clear evidence about the effects of combining some drugs with meth, but for other drugs the evidence is less clear and the effect is unknown. But remember, a lack of evidence doesn't mean it's safe.
Medications for psychotic disorders (antipsychotics)
Medications used to treat psychotic disorders such as schizophrenia can stop working when people use meth as blood levels of these medications are often reduced. Without an adequate level of the medication in the blood, psychotic symptoms can return. Risk of seizures (fits) is also increased.
Regular doses of HIV medications are crucial for HIV positive people, but medications are often forgotten when a person is bingeing on meth.
Mixing meth and HIV medications can also cause meth toxicity (overdose) so it's very important to discuss the risks with your prescribing doctor.
When combined with meth, alcohol can increase blood pressure and heart rate more than meth alone, which places a greater burden on the heart. Meth can also stop you from feeling drunk even when your blood alcohol levels are high so never drive a car even if you think you're ok or feel sober.
Meth users sometimes take more benzos than they intend. Like alcohol, even if you don't feel tired or relaxed, benzos will still effect you and your coordination.
Reduce your risk of accidents and becoming dependent on benzos by keeping track of how many pills you take and how often.
Avoid taking more than prescribed by your doctor. If they haven't been prescribed for you, take regular breaks and watch out for withdrawal symptoms when you cut down or stop (e.g. anxiety; difficulty concentrating; sleeping problems; headaches; sensitivity to loud noises/light/touch; feelings of unreality; numbness; metallic taste in the mouth; pain; stiffness and muscular spasms).
Benzo withdrawal is life threatening and can result in uncontrolled fits if untreated. If you've been taking benzos regularly and think you might be dependent, you need professional support to wean off it slowly and safely.
Some people use cannabis to soften the edges when coming down from meth. Smoking cannabis can make some people feel more paranoid though, and for those people who already have a mental illness such as schizophrenia, or who are vulnerable to psychosis, cannabis can make symptoms worse.
Opioids (heroin, methadone, codeine etc)
Mixing meth with opioids can increase the risk of overdose. Because meth can delay the 'rush' from heroin, people can end up using much more than they're used to. It's also been suggested that the heart might be affected by the combination of these two drugs as meth stimulates heart rate, while opioids slow heart rate and breathing.
Medications for depression (antidepressants)
Some medications that stop excess serotonin from being recycled (called SSRIs), tricyclic antidepressants, and particularly monoamine oxidase inhibitors (MAOIs), when taken within the same two weeks as meth, can cause dangerously high blood pressure, overheating, fits, heart attack, stroke, and kidney failure. Always discuss the risks with your doctor, and always be honest about your meth use. If you need to take medication for depression you really need to take a break from using meth.
Other stimulants (ecstasy, cocaine etc)
Other psychostimulants such ecstasy and cocaine can interact with meth to increase a user’s risk of heart attack, stroke and psychosis.
How does meth work
Meth causes the brain to quickly release a huge amount of certain brain chemical messengers known as neurotransmitters, and keep them circulating for a long time.
Neurotransmitters are released from a neuron, travel across a small space known as a synapse, and attach to another neuron that’s been programmed to accept it – called a receptor. The neurostransmitters affected by meth are dopamine, which is responsible for memory, concentration, behaviour, and feelings of pleasure, and noradrenaline which prepares the body to fight or run away from a threat (‘fight or flight’ mode). Meth also affects serotonin.
Dopamine controls movement, keeps our attention focused and our memory working well. It’s also responsible for feelings of pleasure when we do things that are essential for our survival such as eating, drinking, and sex: when we feel good we’re motivated to do these things again.
Noradrenaline is the ‘fight or flight’ neurotransmitter that prepares us to respond to threats. It increases heart rate and blood pressure, widens air passages in the lungs, dilates the pupils to improve vision, and narrows blood vessels in organs that aren’t needed for defence such as the stomach.
Serotonin regulates temperature, blood pressure, and appetite; helps us to sleep, think, and to perceive our environment accurately. It’s also involved in how we tolerate pain and sexual behaviour. Importantly, it helps us to regulate our emotions.
Meth quickly raises the level of these neurotransmitters and also blocks the neuron’s natural ability to reabsorb the excess - known as 're-uptake'. Normal physical processes are accelerated and users often have little appetite, are wide awake, and feel energetic, confident, sociable and euphoric.
The problem is that there are only so many of these neurotransmitters stored at any one time - think of a glass full of ‘happy’ messengers - so after a while the glass empties and even if a person uses meth, he or she will still feel pretty awful. There are just too few neurotransmitters left to tell the brain to feel good. It’s like overdrawing a bank account – no matter how many times you go back to the bank, the balance is still zero until a deposit is made.
So, it takes rest, a good diet, and most of all time for neurons to restock neurotransmitter stores. Until then, people can feel pretty flat, moody, irritable, forgetful, restless and exhausted: kind of the opposite feeling you'd expect to get from using meth. This is also when people often get strong meth cravings.