Serotonin Syndrome: Understanding the Risks

Many people are unaware of the risks until symptoms occur, but the consequences can be serious. In this article we will look at the causes of drugs serotonin syndrome, potential warning signs and when medical intervention may be necessary.

What Is Serotonin Syndrome?

Serotonin syndrome, also known as serotonin toxicity, is caused when there is too much serotonin in the body. Serotonin is a chemical messenger that carries signals between nerve cells and is important for regulating moods. It is linked to numerous functions and processes, including sleep quality, appetite and even memory.

Serotonin is probably best known for making us feel good. It regulates anxiety and boosts happiness. It is sometimes known as ‘the happy hormone’, in fact, but in this case you can certainly have too much of a good thing.

Serotonin syndrome can cause a number of effects, including changes to the mental state, including confusion and agitation, muscle tremors, cardiovascular issues and hyperthermia or extreme overheating.

The most serious cases, if left untreated, can lead to coma and even death.

Which Drugs Are Most Commonly Linked to Serotonin Syndrome?

Serotonin may be triggered by upping the dosage of a drug you are already taking, combining drugs that increase serotonin levels, or misusing drugs that boost serotonin levels. These can include prescription medications, illicit drugs and emerging substances or designer drugs.

The NHS says the main categories associated with serotonin syndrome are drugs known as serotonin-reuptake inhibitors, monoamine oxidase inhibitors and serotonin-releasing agents. These include antidepressants such as amitriptyline and clomipramine, opioids such as fentanyl and tramadol, and illicit serotonin-releasing drugs such as amphetamines and ecstasy.

Why Is Serotonin Syndrome Becoming a Growing Concern?

Serotonin syndrome is a serious and growing concern due partly to the rise of polydrug use – which can involve the use of multiple substances that may be illicit or prescribed – and attempts at self-medication.

Awareness of serotonin syndrome also remains relatively low despite the potential dangers.

Early Warning Signs People Often Miss

Serotonin syndrome can be very serious if left untreated. It is highly treatable though and is not usually dangerous as long as the affected person gets treatment, and their serotonin levels return to normal. This is why it is very important to recognise early warning signs and get treatment as soon as possible.

Some symptoms that may initially seem harmless or unrelated, however, serotonin syndrome can sometimes be mistaken for other conditions.

Some signs to look out for could include:

• High blood pressure
• Irregular heartbeat
• Overheating
• Excessive sweating
• Tremors and involuntary muscle contractions
• Over-responsive reflexes
• Anxiety
• Agitation
• Confusion

When Does Serotonin Syndrome Become a Medical Emergency?

While serotonin syndrome is treatable, symptoms can escalate quickly. Prompt medical attention can be critical but should always be sought immediately if you or someone else is experiencing:

• A high fever
• Severe confusion or delirium
• Loss of consciousness
• Severe muscle issues
• Cardiovascular distress

Recreational Drug Use and Serotonin Syndrome

Many drugs that are used recreationally, including both illicit substances and prescription medications that are misuses, have an effect on serotonin levels. This is one of the main reason many are sought out, in fact.

Festival, party, and club drug environments may increase risk due to heat and activity levels. People may mix drugs more freely and the purity and presence of unknown ingredients in drugs can also complicate matters.

Can Certain Drug Combinations Increase the Risk?

Different drugs can interact with each other in unpredictable ways and medications should be carefully managed by relevant clinicians, while patients should always take care to use prescription drugs only as directed. There can still sometimes be issues though and adding misused substances – whether illicit substances or misused prescription drugs – can also add to the risks.

Research suggests that most cases of serotonin syndrome involve the use of two or more drugs that increase serotonin levels in different ways. For example, opioids such as tramadol and pethidine may present a particular risk when combined with serotonergic antidepressants.

Any combination of drugs should always be reviewed by a medical professional and it should be remembered that recreational drugs that affect serotonin levels can interact, not only with each other but also with some properly used prescription medications.

Who Is Most at Risk?

People who take multiple medications may be more at risk, although this depends on the drugs involved. Monoamine oxidase inhibitors (MAOIs) are frequently involved in cases of serotonin syndrome. They are one of the oldest classes of antidepressants, although they are used less commonly now.

Individuals with impaired metabolism and the elderly may also be more at risk. People with substance misuse disorders and recreational drug users may put themselves at risk, especially if combining different drugs that affect serotonin levels, or combining recreational and prescription drugs.

Recovery, Treatment and Long-Term Outlook

In most cases, serotonin syndrome can be effectively treated by removing the medications or substances that are implicated and managing any symptoms that the patient is experiencing. In mild cases it may take 24-48 hours for serotonin levels to stabilise, although this can vary depending on the substances involved.

Management of symptoms will depend on the type and severity of those symptoms. For example, hyperthermia may be treated with rapid cooling and benzodiazepines may be prescribed for symptomatic relief of anxiety, agitation and muscle rigidity.

Once the symptoms have been managed, existing treatments with implicated medicines may be restarted in a carefully controlled and monitored manner that may involve lower doses or different combinations of drugs.

What Does Serotonin Syndrome Tell Us About Substance Misuse?

Serotonin syndrome can occur when people are using properly prescribed medicines, but it may sometimes be an indicator of other issues, including the misuse of prescription drugs and illicit substances that can affect serotonin levels. In some cases this may involve taking larger doses or combining prescription drugs in a way that has not been prescribed. In others it may involve illicit drugs interacting with each other or with legitimate medications.

Combining drugs of any kind can be unpredictable and dangerous, but serotonin syndrome is a risk that many people are unaware of. If substance misuse is becoming difficult to manage, it is always best to seek professional help as soon as possible in order to minimise those risks.