As pharmaceutical knowledge improves and a prescription ordering service helps patients with a growing number of complex conditions, more people are taking a combination of medications to treat certain conditions.

This is not a problem on its own, but the more medications that are taken, the greater the risk of side effects caused by problematic polypharmacy, defined by the NHS Specialist Pharmacy Service as prescribing or taking more medicines than are clinically appropriate.

Whilst there is no specific number of medications that would describe polypharmacy, the most accepted number of prescription medicines that would qualify is five or more. There are 8.4m people in England according to an NHS review that are prescribed this on a regular basis.

The concern is that with prescription medications, in particular, there is an increased risk of taking two medicines or taking a medicine in combination with another substance that had a harmful side effect.

Here are some common combinations that should be avoided if at all possible.

Warfarin And Cranberry Juice

Warfarin is a commonly used blood thinning medication that reduces the risks and effects of blood clots. 

However, this also means that a lot of other parts of a person’s diet and lifestyle need to be taken care of as well to avoid taking medication that could cause them to bleed more heavily.

This means that warfarin has a huge number of medicines and foods that can affect it, such as food and drink with a lot of vitamin K(which includes avocado, mature cheese, broccoli, liver and olive oil), as well as grapefruit and cranberry juice.

A lot of common medicines such as aspirin and ibuprofen also react with warfarin, which means there is a real chance of having multiple foods and medicines that affect a single drug and significantly increase the risk of bleeding.

Lisinopril And Bananas

Lisinopril is a medication that helps to treat high blood pressure and heart failure and can sometimes be used in an emergency to help keep someone alive after a heart attack. 

However, it also increases the levels of potassium in your blood, which if taken with supplements or large amounts of potassium-rich foods such as bananas can lead to hyperkalemia that can lead to life-threatening heart problems.

What makes this concerning is that in most cases when blood pressure medication is recommended, potassium-rich diets are similarly suggested and this serves as an antithesis to this.

Opiates And Alcohol

An all-too-common cause of overdose and potentially lethal side effects is taking opiates in combination with substances that contain alcohol, in part because so many prescription medications are affected by alcohol in one way or another.

This is in part because alcohol naturally impairs memory and brain function, meaning that it can be easy to simply forget when you last took prescription medication, but with opiates, there is a more concerning combined effect.

The combination can create a feeling of euphoria or greater pain relief but in practice enhances the sedative effect of both substances, which can lead to overdose, respiratory depression and potentially lethal consequences.